wjnstWorld Journal of Nuclear Science and Technology2161-68092161-6795Scientific Research Publishing10.4236/wjnst.2026.163005wjnst-152626ArticleEngineeringPhysicsMathematicsLow Doses of Gamma Radiation Induce Cellular Stress Associated with Hsp70 Expression in HaCat CellsJuárezManuel Venancio Muñoz1VergilJesús Rodríguez1DávilaKevin Said Ramírez1LópezDavid Alejandro García1LeónConsuelo Letechipía De2LunaMaría Argelia López3LópezJesús Adrián4CamachoDiego Armando Alvarado1BenitezCarlos Eduardo Loera1RodríguezSergio Hugo Sánchez1 Laboratorio de Biología Celular y Neurobiología, Unidad Académica de Ciencias Biológicas, Universidad Autónoma de Zacatecas, Zacatecas, México Laboratorio de Radiobiología, Unidad Académica de Estudios Nucleares, Universidad Autónoma de Zacatecas, Zacatecas, México Unidad Académica de Ciencias Químicas, Universidad Autónoma de Zacatecas, Campus UAZ Siglo XXI, Zacatecas, México Laboratorio de MicroARNs y Cáncer, Unidad Académica de Ciencias Biológicas, Universidad Autónoma de Zacatecas, Zacatecas, México
The authors declare no conflicts of interest regarding the publication of this paper.
Ionizing radiation is widely used in the diagnosis and treatment of diseases; however, cumulative exposure, even within doses considered permissible, can induce cellular damage, particularly in the skin, as it is the first organ exposed. In this context, the present study aimed to evaluate changes in the expression of the Hsp70 protein as a bioindicator of cellular stress in HaCaT epithelial cells exposed to low doses of gamma radiation. To this end, HaCaT cells cultured in vitro were irradiated using a 137Cs source, and Hsp70 expression was subsequently analyzed by SDS-PAGE, Western blotting, and immunodetection. Basal Hsp70 expression was detected in non-irradiated cells, as well as an increase in expression under heat stress conditions. Following exposure to the radiation field, an increase in Hsp70 expression was observed at a dose of 73.7 µGy, followed by a slight decrease as the dose increased. These findings suggest a dose-dependent response in Hsp70 expression to gamma radiation and demonstrate that exposure to low doses induces cellular stress in HaCaT cells, as reflected by changes in the expression of this protein. Taken together, these results support the potential use of Hsp70 as an early biomarker of cellular stress and may contribute to the development of more effective radiological protection and safety strategies for low-dose radiation exposures.
Biological organisms are increasingly exposed to low or high doses of gamma radiation, particularly humans, through clinical diagnostic procedures, the application of nuclear analytical techniques, and radiological accidents. Low levels of gamma radiation pose a stochastic health risk, defined as the probability of inducing genetic damage and cancer, whereas high doses produce deterministic effects, meaning the severity of acute tissue damage that will occur with certainty. Acute exposure to high doses rapidly leads to significant injury, and the long-term effects of exposure include health problems ranging from fibrosis to cancer [1][2].
The interaction of gamma rays with cells and the damage they cause is a function of probability [3][4]. Since cellular repair usually occurs, damage to living tissue is not necessarily permanent, considering that energy deposition within a cell occurs very rapidly, approximately within 10−18 seconds, and randomly. These interactions and the resulting cellular damage may affect organs and the organism as a whole; however, it should be noted that there is no single specific type of cellular damage uniquely associated with radiation. The action of radiation on the cell can be classified as either direct or indirect, depending on the medium in which energy transfer occurs [5][6]. In direct interactions, the entire cell is affected because its macromolecules (proteins or DNA) are damaged to an extent that results in cell death or DNA mutations [7]. One of the main causes of this type of cell death is DNA double-strand breaks (DSBs), since if they are not repaired or are repaired incorrectly, DSBs can lead to chromosomal aberrations and human diseases, including cancer [5][8]. Indirect action occurs when radiation energy is deposited in the cell and interacts with water rather than with macromolecules [9]. Since most living organisms are composed largely of water, the probability of an event occurring in a water molecule is very high. This interaction causes radiolysis of the water molecule, resulting in the formation of highly reactive free radicals (reactive oxygen species and reactive nitrogen species) that are potentially toxic to the cell [5].
These biological effects or damages in molecules and cellular structures activate intracellular mechanisms that attempt to maintain homeostasis and cell survival; one such mechanism involves the expression of heat shock protein 70 (Hsp70) [10]-[14]. In 1962, Ritossa discovered a group of proteins known as heat shock proteins (Hsps) [15]. Most function as molecular chaperones, possessing the ability to bind to other proteins and mediate their folding, transport, and interactions with other proteins. They comprise a family of highly conserved proteins classified according to their molecular weight. Their expression is induced in both prokaryotic and eukaryotic cells in response to various physiological and environmental stressors, such as heat shock, inflammation, infections, environmental contaminants, ultraviolet radiation, low-frequency radiation, and gamma radiation fields. They are also expressed in malignant neoplasms, contributing to tumor growth, differentiation, invasion, and metastasis; in tumor cells, they play an important role in tumorigenesis by inhibiting apoptosis and senescence [16].
The induction of Hsps in response to stress protects against the initial insult and generates a state of stress resistance within the cell. This protective role has been attributed to several functional properties, including the prevention of protein aggregation and the promotion of protein disaggregation through the catalysis of refolding of damaged or denatured proteins [17]. Therefore, heat shock proteins are essential for survival under adverse environmental conditions [18].
Hsp70 is the most evolutionarily conserved member of this family, existing in constitutive and inducible forms and being localized in different intracellular organelles. Under normal conditions, its primary function is to mediate the folding and transport of newly synthesized proteins. Additionally, it restores proteome homeostasis by assisting in the refolding or elimination of denatured proteins through its ATPase activity. During cellular stress processes that result in protein damage or abnormal folding, Hsp70 processes these molecules by either refolding or degrading them. It has been demonstrated that following heat shock, Hsp70 accumulates within the nucleolus, the cellular structure responsible for ribosome production. It also provides protection to the centrosome and intermediate filaments [19].
In its constitutive form, Hsp70 is expressed at low levels in healthy, unstressed cells, whereas its heat-inducible form is rapidly expressed during cellular stress and throughout cell-cycle progression. This process begins with signaling cascades involving extracellular signal-regulated mitogen-activated protein kinase (MAPK/ERK) and stress-activated protein kinase (SAPK), which activate heat shock factors [20].
Several recent studies have demonstrated that Hsp70 modulates the progression of apoptosis induced by a wide variety of stimuli [17]. During apoptotic signaling, high Hsp70 expression interferes with multiple steps, including cytochrome c release, caspase activation, accumulation of misfolded proteins, generation of reactive oxygen species, and DNA fragmentation. Inhibition of Hsp70 increases cellular sensitivity to apoptosis. Therefore, Hsp70 directly or indirectly modulates both intrinsic and extrinsic apoptotic pathways [21].
The skin is the first biological barrier exposed to radiation, and its outermost layer is composed of cells known as keratinocytes. The biological model used in this study consisted of HaCaT cells, an immortalized human keratinocyte cell line [22][23], which were exposed to low gamma-radiation fields to subsequently evaluate the potential damage generated by this factor.
One of the most extensively investigated biological mechanisms used by both prokaryotic and eukaryotic cells to cope with potential damage generated by gamma-radiation exposure is the activation of heat shock protein (Hsp) expression [19]. Among this family of proteins, Hsp70 is considered a bioindicator used to assess cellular damage resulting from exposure to ionizing radiation [11][13][14].
Considering the above, the objective of this study was to evaluate changes in Hsp70 protein expression as a biomarker of cellular stress in HaCaT cells exposed to low doses of gamma radiation. This work contributes to a deeper understanding of the biological effects triggered by exposure to low-dose gamma radiation.
2. Materials and Methods2.1. Study Model
Human keratinocytes from the HaCaT cell line were used as the experimental model.
2.2. Cell Culture
HaCaT cells were obtained from the American Type Culture Collection and cultured at 36.5˚C in disposable plastic culture flasks (Costar 3151, Cambridge, MA) under a controlled atmosphere of 95% air and 5% carbon dioxide (SteriCult 200, Forma Scientific, Ohio). Cells were maintained in 20 mL of Dulbecco’s Modified Eagle Medium (cDMEM; D1152, Sigma Chemical Co., St. Louis, MO) supplemented with penicillin (100 U/mL), streptomycin (100 μg/mL; In Vitro, Mexico), insulin (0.08 U/mL; Eli Lilly, Mexico), and 10% certified fetal bovine serum (FBS) (Gibco BRL, 16000-028, Grand Island, NY).
For cell detachment, trypsin combined with EDTA (In Vitro, Mexico) was used to promote cell dissociation through calcium chelation and disruption of substrate adhesion interactions. Cells were subsequently seeded in polystyrene culture dishes (Costar) until reaching a confluence of 5 × 106 cells/mL, using a total of 15 culture dishes.
Of the total dishes, three were exposed to 40˚C for 40 minutes and used as positive controls to induce Hsp70 expression; three were maintained without heat or radiation exposure and used as negative controls; and the remaining nine were exposed to a 137Cs radioactive source. Overall, the experimental design included three biological replicates for each exposure condition.
2.3. HaCaT Cells Exposed to Gamma Radiation
The samples were irradiated by placing each cell culture (contained in a Petri dish) on a plastic platform positioned 10 cm from a 137Cs source emitting 0.662 MeV gamma rays, located at the Academic Unit of Nuclear Studies (UAEN), Autonomous University of Zacatecas (UAZ). The radioactive source was positioned at the center of the experimental setup (Figure 1), and the experimental samples were arranged around it at a distance of 10 cm.
All procedures were carried out inside an incubator to maintain the temperature at 37˚C, and the exposure process was performed in accordance with the regulatory radiological protection measures established for sealed radioactive sources. During exposure to the 137Cs source, the absorbed doses were calculated.
Following irradiation, the cultures were incubated for 45 minutes at 37˚C to allow the cells to activate their homeostatic mechanisms involved in nuclear and protein repair.
Figure 1. Experimental setup used for irradiation of HaCaT cells with gamma radiation from a 137Cs source.
2.4. Absorbed Dose Analysis Using TLD-100 Dosimeters (Calibration)
Thermoluminescent dosimeters (TLDs) type 100 (lithium fluoride, natural Li), Harshaw ribbon-type dosimeters measuring 3.2 × 3.2 × 0.89 mm, were used. TLD-100 dosimeters are widely employed for X-ray and gamma-ray dosimetry in the range of 10 pGy to 10 Gy. Prior to use, the TLDs were annealed at 400˚C for 1 hour to erase any residual signal.
During exposure, groups of four TLDs were placed in Eppendorf tubes. The TLD-100 groups were exposed for 0, 60, 90, and 150 seconds at a distance of 10 cm from the 137Cs source and the samples. One group of TLD-100 dosimeters was used to measure background radiation (0 exposures).
The same procedure was repeated using a RaySafe ThinX RAD solid-state monitor, which was activated during sample exposure to the 137Cs source. The same number of exposure times used for the thermoluminescent dosimeters was employed with the RaySafe equipment.
2.5. Absorbed Dose Calculation
During gamma-ray exposure, TLDs were used to calculate the absorbed dose. Their response was measured using a Harshaw 3500 reader by heating the dosimeters in a nitrogen atmosphere from 50˚C to 350˚C at a rate of 10˚C/s.
The responses from each exposed TLD group were averaged and corrected using the mean response of the TLDs employed for background measurements. These values were correlated with the readings obtained from the RaySafe monitor, resulting in a strong correlation (r2 = 0.9987) between the TLD response, expressed in nanocoulombs, and the number of exposures of cells subjected to the 137Cs source.
2.6. Cell Lysis
Following irradiation, cells were washed with 3 mL of cold phosphate buffer (pH 7.2; Gibco BRL, Grand Island, NY, USA, 21300-58) and subsequently lysed with 500 μL of lysis buffer containing 1% Triton X-100, 140 mM NaCl, 1 mM EDTA, 10 mM Tris-HCl (pH 7.6), and a protease inhibitor cocktail (11697498001, Roche Diagnostics).
Using a cell culture scraper, the bottom surface of each Petri dish was scraped to obtain the cellular extract. Cell extracts were collected, homogenized, and centrifuged at 14,000 rpm for 10 min at 4˚C to obtain the soluble protein fraction present in the supernatants.
2.7. Protein Quantification
Protein quantification was performed using the soluble fraction obtained after cell lysis according to the method described by Bradford (1976) [24].
2.8. Determination of Hsp70 and Tubulin Expression by SDS-PAGE and Western Blot-ECL
Hsp70 and Tubulin (constitutive control) protein expression was analyzed for each experimental unit. Twenty micrograms (20 μg) of total protein were separated on 7.5% SDS-polyacrylamide gels according to the method described by Laemmli (1970) [25].
Following electrophoresis, proteins contained in the polyacrylamide gels were transferred onto nitrocellulose membranes (Hybond-C RPN 303 C, Amersham, Little Chalfont, Buckinghamshire) using the method described by Towbin et al. (1979) [26].
2.9. Immunodetection
The proteins retained on the nitrocellulose membranes were subjected to immunodetection. Non-specific binding sites were blocked overnight at 4˚C with a 3% casein-PBS solution.
After blocking, the membranes were incubated with the primary monoclonal antibody against Hsp70 (SC-24, Santa Cruz Biotechnology®, USA) and anti-β Tubulin (T-5293, SigmaAldrich®, USA) at a dilution of 1:1000 for 1 hour at room temperature under gentle agitation (25 rpm). Membranes were then washed seven times alternately with PBS and PBS-Tween solutions (5 min per wash, 45 rpm agitation).
Subsequently, the peroxidase-conjugated secondary antibody against mouse IgG (anti-mouse IgG-HRP conjugate, SC-2005, Lot F0412, Santa Cruz Biotechnology®, USA) was added and incubated for 1 hour, followed by eight additional washes.
For signal detection, an enhanced chemiluminescence (ECL) solution (GERPN2232-ECLTM Prime Western Blotting System) was applied to the membranes. This reagent interacted with the HRP-conjugated antibody and generated a photoluminescent signal. Signal intensity was analyzed using the Image Lab imaging system (Bio-Rad® Laboratories) to perform optical densitometric analysis and determine the level of Hsp70 and Tubulin (constitutive control) protein expression [27].
2.10. Statistical Analysis
Three biological replicates were performed for each gamma-irradiation condition and control group. Statistical analyses were conducted using Microsoft Excel® and GraphPad Prism version 8.0.1.
Differences among experimental groups were evaluated using one-way analysis of variance (ANOVA), followed by Dunnett’s post hoc test to compare each experimental condition with the control group. Results were graphically represented using GraphPad Prism and expressed as mean ± standard error of the mean (SEM). A value of p < 0.05 was considered statistically significant.
3. Results3.1. Cell Culture, Irradiation, and Absorbed Doses
Confluent HaCaT cell cultures were irradiated using a 137Cs source that emits gamma radiation. The irradiation periods were 1, 1.5, and 2.5 minutes. During this process, the absorbed doses received by the cell cultures were calculated.
Thermoluminescent dosimeters (TLDs) were used, and the average response of each dosimeter group was determined and corrected using the mean response of the TLDs employed for background measurements. The absorbed doses corresponded to 73.7 µGy after 1 minute of exposure, 110.5 µGy after 1.5 minutes, and 184.3 µGy after 2.5 minutes (Table 1).
Table 1. Absorbed dose in each of the samples as a function of exposure time.
Sample
Irradiation time
Dose (µGy)
1
Control, not irradiated
0.0
2
Exposure to 40˚C for 40 minutes
0.0
3
1 minute
73.5
4
1.5 minutes
110.5
5
2.5 minutes
184.3
3.2. Hsp70 Protein Expression
Following the irradiation of HaCaT cells, Hsp70 protein expression was evaluated in each experimental unit using Western blot-ECL analysis (Figure 2). Densitometric analysis of the Hsp70 and Tubulin bands obtained was subsequently performed.
The mean optical densities obtained from the immunodetections showed significant differences compared with the basal control. As expected, the positive control subjected to heat treatment at 40˚C exhibited the highest Hsp70 expression. This was followed by the 1-minute exposure group corresponding to a dose of 73.7 µGy, then the 1.5-minute exposure group receiving 110.5 µGy, and finally the 2.5-minute exposure group receiving 184.3 µGy.
Analysis of the optical density values revealed an increase in Hsp70 expression at 73.7 µGy. Subsequently, as the radiation dose increased, Hsp70 expression progressively decreased (Figure 3).
Figure 2. Expression of Hsp70 and Tubulin in HaCaT cells exposed to low doses of gamma radiation. Western Blot-ECL technique.
(a) (b)
Figure 3. Optical density measurements of Hsp70 expression (±S.E.) and Tubulin in HaCaT cells exposed to low doses of gamma radiation (73.7 µGy, 110.5 µGy and 184.3 µGy).
4. Discussion
In the present study, the expression of a biomarker of cellular stress induced by low doses of gamma radiation was evaluated. The results showed the presence of Hsp70 protein in the control samples analyzed. These findings are consistent with previous studies demonstrating that Hsp70 is constitutively and ubiquitously expressed in eukaryotic cells, where it plays an essential role in maintaining cellular function [12]-[14][28]-[31].
Likewise, analysis of Hsp70 expression in cells exposed to low doses of gamma radiation revealed an increase compared with the control group, with the first dose (73.7 µGy) producing the most significant quantitative increase (p < 0.05). It is noteworthy that the heat-induced expression of Hsp70 was very similar to that observed during the first minute of exposure to gamma radiation. These findings are consistent with reports from different experimental models exposed to gamma rays. For example, irradiated C3H 10T1/2 and NIH3T3 mouse cells exhibited increased Hsp70 expression following irradiation [32]. Similar observations have been reported in cells recovered from the salivary glands of one of the most radioresistant organisms known, Chironomus ramosus [33]. In human leukocytes exposed to low gamma-radiation fields, Hsp70 overexpression has also been documented [14].
In a study reported by Murakami et al. [34], the expression of several proteins involved in apoptosis was analyzed in irradiated cells, leading to the conclusion that Hsp70 plays an important role in cellular recovery under stress conditions. Furthermore, low doses of gamma radiation have been shown to accelerate the differentiation process in keratinocytes (HaCaT cells), accompanied by the expression of involving and p21 proteins, both associated with cellular differentiation [35].
It is also known that Hsp70 expression promotes adaptive responses to various stressors, including heat, ionizing radiation, and reactive oxygen species. Radioadaptive effects induced by low doses of gamma radiation have been demonstrated in acinar cells of the parotid salivary gland of Rattus norvegicus [36]. In myeloid leukemia cells, improvements in colony-forming capacity and increased Hsp70 mRNA expression have been reported, although no changes in Hsp70 protein levels were observed [37]. Collectively, these findings suggest that low-dose radiation-induced cellular stress modulates Hsp70 expression and may contribute to the development of radioadaptive responses. However, although radioadaptation may occur, it is also important to consider that repeated exposure to low-dose radiation fields may generate stochastic risks due to cumulative dose effects.
The analysis of Hsp70 expression also reflects the degree of stress imposed by the low-intensity gamma-radiation field to which keratinocytes are exposed. From a dosimetric perspective, it is important to consider any specific quantity or unit of natural or artificial radiation to which the human body is exposed, since the present study demonstrates that even low-dose exposures can elicit a cellular stress response, evidenced by increased Hsp70 expression. These observations highlight the importance of establishing more precise radiation-protection standards and occupational exposure limits for ionizing radiation [38][39].
Taken together, the results of the present study suggest that exposure to low doses of gamma radiation induces a cellular stress response, as evidenced by increased Hsp70 expression in HaCaT keratinocytes. However, these findings should be interpreted with caution and do not allow a direct conclusion that HaCaT cells exhibit radiosensitivity or that the low doses evaluated necessarily lead to progressive accumulation of cellular damage over time. This study did not assess direct indicators of biological injury, such as DNA damage, cell survival, proliferative capacity, apoptosis, senescence, or mechanisms of sustained cellular adaptation.
Therefore, the observed overexpression of Hsp70 should primarily be regarded as a marker of stress-response activation under the experimental conditions evaluated. Future studies incorporating genotoxicity biomarkers, functional survival assays, and repeated-exposure or longitudinal assessments will be necessary to determine whether this response is associated with radioadaptive processes, maintenance of cellular homeostasis, or, alternatively, cumulative effects resulting from exposure to low doses of ionizing radiation.
5. Conclusion
Exposure of HaCaT cells to low doses of gamma radiation from a 137Cs source induced cellular stress, as evidenced by the expression of the Hsp70 biomarker. The data generated suggest that the early expression of Hsp70 may serve as valuable information for the implementation of safer radiological protection measures, not only in the context of high-dose radiation exposure but also for low-dose exposures. This is particularly relevant because the effects of low-dose radiation may accumulate over time, potentially leading to significant biological alterations in the future, especially among occupationally exposed personnel.
ReferencesMoroni, M., Maeda, D., Whitnall, M., Bonner, W. and Redon, C. (2013) Evaluation of the γ-H2AX Assay for Radiation Biodosimetry in a Swine Model. International Journal of Molecular Sciences, 14, 14119-14135. https://doi.org/10.3390/ijms140714119 10.3390/ijms14071411923880859https://doi.org/10.3390/ijms140714119Moroni, M.Maeda, D.Whitnall, M.Bonner, W.Redon, C.2013Evaluation of the γ-H2AX Assay for Radiation Biodosimetry in a Swine ModelInternational Journal of Molecular Sciences1410.3390/ijms14071411923880859Zhu, J., Ren, Z., Chen, Y. and Hu, B. (2016) The Biological Effects Induced by High-Charged and Energy Particles and Its Application in Cancer Therapy. International Journal of Radiation Research, 14, 1-7. https://doi.org/10.18869/acadpub.ijrr.14.1.1. 10.18869/acadpub.ijrr.14.1.1https://doi.org/10.18869/acadpub.ijrr.14.1.1Zhu, J.Ren, Z.Chen, Y.Hu, B.2016The Biological Effects Induced by High-Charged and Energy Particles and Its Application in Cancer TherapyInternational Journal of Radiation Research1410.18869/acadpub.ijrr.14.1.1Mohammed, M.R., Ahmed, M.M. and Montaser, S.A. (2022) Cytogenetic and Immunological Efficacy of Nicotiflorin and Rutin Combination on γ Irradiated Rats. International Journal of Radiation Research, 20, 455-460. https://doi.org/10.52547/ijrr.20.2.29 10.52547/ijrr.20.2.29https://doi.org/10.52547/ijrr.20.2.29Mohammed, M.R.Ahmed, M.M.Montaser, S.A.2022Cytogenetic and Immunological Efficacy of Nicotiflorin and Rutin Combination on γ Irradiated RatsInternational Journal of Radiation Research2010.52547/ijrr.20.2.29Kasić, A., Sakić, Z. and Kasumović, A. (2025) Assessment of Outdoor Radiation Dose and Radiological Health Hazards. International Journal of Radiation Research, 23, 921-926.2025Assessment of Outdoor Radiation Dose and Radiological Health HazardsInternational Journal of Radiation Research23Bayo, N.A. (2001) Reacción celular ante la radiación. Radiobiología: Revista electrónica, 1, 9-11.Bayo, N.A.2001Reacción celular ante la radiaciónRadiobiología: Revista electrónica1Voos, P., Fuck, S., Weipert, F., Babel, L., Tandl, D., Meckel, T., et al. (2018) Ionizing Radiation Induces Morphological Changes and Immunological Modulation of Jurkat Cells. Frontiers in Immunology, 9, Article 922. https://doi.org/10.3389/fimmu.2018.00922 10.3389/fimmu.2018.0092229760710https://doi.org/10.3389/fimmu.2018.00922Voos, P.Fuck, S.Weipert, F.Babel, L.Tandl, D.Meckel, T.2018Ionizing Radiation Induces Morphological Changes and Immunological Modulation of Jurkat CellsFrontiers in Immunology992210.3389/fimmu.2018.0092229760710Helm, J.S. and Rudel, R.A. (2020) Adverse Outcome Pathways for Ionizing Radiation and Breast Cancer Involve Direct and Indirect DNA Damage, Oxidative Stress, Inflammation, Genomic Instability, and Interaction with Hormonal Regulation of the Breast. Archives of Toxicology, 94, 1511-1549. https://doi.org/10.1007/s00204-020-02752-z 10.1007/s00204-020-02752-z32399610https://doi.org/10.1007/s00204-020-02752-zHelm, J.S.Rudel, R.A.Damage, OStress, I2020Adverse Outcome Pathways for Ionizing Radiation and Breast Cancer Involve Direct and Indirect DNA Damage, Oxidative Stress, Inflammation, Genomic Instability, and Interaction with Hormonal Regulation of the BreastArchives of Toxicology9410.1007/s00204-020-02752-z32399610Vignard, J., Mirey, G. and Salles, B. (2013) Ionizing-radiation Induced DNA Double-Strand Breaks: A Direct and Indirect Lighting Up. Radiotherapy and Oncology, 108, 362-369. https://doi.org/10.1016/j.radonc.2013.06.013 10.1016/j.radonc.2013.06.01323849169https://doi.org/10.1016/j.radonc.2013.06.013Vignard, J.Mirey, G.Salles, B.2013Ionizing-radiation Induced DNA Double-Strand Breaks: A Direct and Indirect Lighting UpRadiotherapy and Oncology10810.1016/j.radonc.2013.06.01323849169Bolus, N.E. (2017) Basic Review of Radiation Biology and Terminology. Journal of Nuclear Medicine Technology, 45, 259-264. https://doi.org/10.2967/jnmt.117.195230 10.2967/jnmt.117.19523029203550https://doi.org/10.2967/jnmt.117.195230Bolus, N.E.2017Basic Review of Radiation Biology and TerminologyJournal of Nuclear Medicine Technology4510.2967/jnmt.117.19523029203550Vega-Carrillo, H.R., Manzanares-Acuña, E., Bañuelos-Valenzuela, R., Montaño Zentina, L.M. and Herrera Corral, G. (2011) Human Lymphocytes Response to Low Gamma-Ray Doses. AIP Conference Proceedings, 630, 146-152. https://doi.org/10.1063/1.3682855 10.1063/1.3682855https://doi.org/10.1063/1.3682855Vega-Carrillo, H.R.Valenzuela, R.Zentina, L.M.Corral, G.2011Human Lymphocytes Response to Low Gamma-Ray DosesAIP Conference Proceedings63010.1063/1.3682855García López, D.A., Reveles Hernández, R.G., Ramírez Santoyo, R.M., Vidales Rodríguez, L.E., López Luna, M.A. and Sánchez Rodríguez, S.H. (2023) Alteración en viabilidad celular, daño en adn y cambios en la expresión de hsp70 en leucocitos humanos expuestos a radiación uva y calor. Estudos em Biociências e Biotecnologia: Desafios, Avanços e Possibilidades II, 11, 14-25. https://doi.org/10.37572/edart_3105238352 10.37572/edart_3105238352https://doi.org/10.37572/edart_3105238352Santoyo, R.M.Luna, M.A.Desafios, A2023Alteración en viabilidad celular, daño en adn y cambios en la expresión de hsp70 en leucocitos humanos expuestos a radiación uva y calorEstudos em Biociências e Biotecnologia: Desafios1110.37572/edart_3105238352García-López, D.A., Ortiz-Letechipia, J., Bañuelos-Valenzuela, R., Reveles-Hernández, R.G., Ramírez-Santoyo, R.M. and Sánchez-Rodríguez, S. (2024) Disparidad en daño al ADN, Hsp70 y apoptosis, por UVA en leucocitos ovinos y humanos. Revista MVZ Córdoba, 29, e3176. https://doi.org/10.21897/rmvz.3176 10.21897/rmvz.3176https://doi.org/10.21897/rmvz.3176Ortiz-Letechipia, J.Valenzuela, R.Santoyo, R.M.ADN, H2024Disparidad en daño al ADN, Hsp70 y apoptosis, por UVA en leucocitos ovinos y humanosRevista MVZ Córdoba2910.21897/rmvz.3176Letechipia, J.O., de León, C.L., Vega-Carrillo, H.R., García López, D.A. and Rodríguez, S.H.S. (2023) Apoptosis and Cellular Stress Induction in Human Leukocytes by Dental X-Rays. Radiation Physics and Chemistry, 204, Article ID: 110650. https://doi.org/10.1016/j.radphyschem.2022.110650 10.1016/j.radphyschem.2022.110650https://doi.org/10.1016/j.radphyschem.2022.110650Letechipia, J.O.Vega-Carrillo, H.R.2023Apoptosis and Cellular Stress Induction in Human Leukocytes by Dental X-RaysRadiation Physics and Chemistry204110650ID10.1016/j.radphyschem.2022.110650Padilla, J.L.S., López, D.A.G., de León, C.L., Vega-Carrillo, H.R. and Rodríguez, S.H.S. (2023) Low-Dose γ Radiation Fields Decrease Cell Viability, Damage DNA, and Increase the Expression of Hsp70 and p53 Proteins in Human Leukocytes. World Journal of Nuclear Science and Technology, 13, 55-72. https://doi.org/10.4236/wjnst.2023.134005 10.4236/wjnst.2023.134005https://doi.org/10.4236/wjnst.2023.134005Padilla, J.L.S.Vega-Carrillo, H.R.Viability, D2023Low-Dose γ Radiation Fields Decrease Cell Viability, Damage DNA, and Increase the Expression of Hsp70 and p53 Proteins in Human LeukocytesWorld Journal of Nuclear Science and Technology1310.4236/wjnst.2023.134005Roh, B.H., Kim, D.H., Cho, M.K., Park, Y.L. and Whang, K.U. (2008) Expression of Heat Shock Protein 70 in Human Skin Cells as a Photoprotective Function after UV Exposure. Annals of Dermatology, 20, 184-189. https://doi.org/10.5021/ad.2008.20.4.184 10.5021/ad.2008.20.4.18427303188https://doi.org/10.5021/ad.2008.20.4.184Roh, B.H.Kim, D.H.Cho, M.K.Park, Y.L.Whang, K.U.2008Expression of Heat Shock Protein 70 in Human Skin Cells as a Photoprotective Function after UV ExposureAnnals of Dermatology2010.5021/ad.2008.20.4.18427303188Letechipia, J.O., López, D.A.G., de León C.L., Vega Carrillo, H.R. and Sánchez Rodríguez, S.H. (2019) Rayos X inducen cambios en laviabilidad celular: Expresiónde Hsp70 y caspasa-8 enleucocitos humanos. Ingenierias, XII, 35-42.Letechipia, J.O.Carrillo, H.R.Ingenierias, X2019Rayos X inducen cambios en laviabilidad celular: Expresiónde Hsp70 y caspasa-8 enleucocitos humanosIngenierias35Beere, H.M., Wolf, B.B., Cain, K., Mosser, D.D., Mahboubi, A., Kuwana, T., et al. (2000) Heat-Shock Protein 70 Inhibits Apoptosis by Preventing Recruitment of Procaspase-9 to the Apaf-1 Apoptosome. Nature Cell Biology, 2, 469-475. https://doi.org/10.1038/35019501 10.1038/3501950110934466https://doi.org/10.1038/35019501Beere, H.M.Wolf, B.B.Cain, K.Mosser, D.D.Mahboubi, A.Kuwana, T.2000Heat-Shock Protein 70 Inhibits Apoptosis by Preventing Recruitment of Procaspase-9 to the Apaf-1 ApoptosomeNature Cell Biology210.1038/3501950110934466Jonak, C., Klosner, G. and Trautinger, F. (2006) Heat Shock Proteins in the Skin. International Journal of Cosmetic Science, 28, 233-241. https://doi.org/10.1111/j.1467-2494.2006.00327.x 10.1111/j.1467-2494.2006.00327.x18489262https://doi.org/10.1111/j.1467-2494.2006.00327.xJonak, C.Klosner, G.Trautinger, F.2006Heat Shock Proteins in the SkinInternational Journal of Cosmetic Science2810.1111/j.1467-2494.2006.00327.x18489262Coronato, S., Di Girolamo, W., Salas, M., Spinelli, O. and Laguens, G. (1999) Biologia de las proteinas del shock térmico. Medicina- Buenos Aires, 59, 477-486.Coronato, S.Girolamo, W.Salas, M.Spinelli, O.Laguens, G.1999Biologia de las proteinas del shock térmicoMedicina-Buenos Aires59Balogi, Z., Multhoff, G., Jensen, T.K., Lloyd-Evans, E., Yamashima, T., Jäättelä, M., et al. (2019) Hsp70 Interactions with Membrane Lipids Regulate Cellular Functions in Health and Disease. Progress in Lipid Research, 74, 18-30. https://doi.org/10.1016/j.plipres.2019.01.004 10.1016/j.plipres.2019.01.00430710597https://doi.org/10.1016/j.plipres.2019.01.004Balogi, Z.Multhoff, G.Jensen, T.K.Lloyd-Evans, E.Yamashima, T.2019Hsp70 Interactions with Membrane Lipids Regulate Cellular Functions in Health and DiseaseProgress in Lipid Research7410.1016/j.plipres.2019.01.00430710597Kumar, S., Stokes, J., Singh, U.P., Scissum Gunn, K., Acharya, A., Manne, U., et al. (2016) Targeting Hsp70: A Possible Therapy for Cancer. Cancer Letters, 374, 156-166. https://doi.org/10.1016/j.canlet.2016.01.056 10.1016/j.canlet.2016.01.05626898980https://doi.org/10.1016/j.canlet.2016.01.056Kumar, S.Stokes, J.Singh, U.P.Gunn, K.Acharya, A.Manne, U.2016Targeting Hsp70: A Possible Therapy for CancerCancer Letters37410.1016/j.canlet.2016.01.05626898980Da Freitas, L., Saenz, A.M., Ruiz, Á. and González, F. (2013) Queratinocitos y queratinización. Dermatología Pediátrica Latinoamericana, 11, 5-11.Freitas, L.Saenz, A.M.2013Queratinocitos y queratinizaciónDermatología Pediátrica Latinoamericana11Deyrieux, A.F. and Wilson, V.G. (2007) In Vitro Culture Conditions to Study Keratinocyte Differentiation Using the HaCaT Cell Line. Cytotechnology, 54, 77-83. https://doi.org/10.1007/s10616-007-9076-1 10.1007/s10616-007-9076-119003021https://doi.org/10.1007/s10616-007-9076-1Deyrieux, A.F.Wilson, V.G.2007In Vitro Culture Conditions to Study Keratinocyte Differentiation Using the HaCaT Cell LineCytotechnology5410.1007/s10616-007-9076-119003021Bradford, M.M. (1976) A Rapid and Sensitive Method for the Quantitation of Microgram Quantities of Protein Utilizing the Principle of Protein-Dye Binding. Analytical Biochemistry, 72, 248-254. https://doi.org/10.1016/0003-2697(76)90527-3 10.1016/0003-2697(76)90527-3942051https://doi.org/10.1016/0003-2697(76)90527-3Bradford, M.M.1976A Rapid and Sensitive Method for the Quantitation of Microgram Quantities of Protein Utilizing the Principle of Protein-Dye BindingAnalytical Biochemistry26977610.1016/0003-2697(76)90527-3942051Laemmli, U.K. (1970) Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4. Nature, 227, 680-685. https://doi.org/10.1038/227680a0 10.1038/227680a05432063https://doi.org/10.1038/227680a0Laemmli, U.K.1970Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature22710.1038/227680a05432063Towbin, H., Staehelin, T. and Gordon, J. (1979) Electrophoretic Transfer of Proteins from Polyacrylamide Gels to Nitrocellulose Sheets: Procedure and Some Applications. Proceedings of the National Academy of Sciences of the United States of America, 76, 4350-4354. https://doi.org/10.1073/pnas.76.9.4350 10.1073/pnas.76.9.4350388439https://doi.org/10.1073/pnas.76.9.4350Towbin, H.Staehelin, T.Gordon, J.1979Electrophoretic Transfer of Proteins from Polyacrylamide Gels to Nitrocellulose Sheets: Procedure and Some ApplicationsProceedings of the National Academy of Sciences of the United States of America7610.1073/pnas.76.9.4350388439Cornejo Romero, A., Serrato Diaz, A., Rendo Aguilar, B. and Rocha Munive, M.G. (2014) Herramientas moleculares aplicadas en ecología: Aspectos teóricos y prácticos. SEMARNAT.Romero, A.Diaz, A.Aguilar, B.Munive, M.G.2014Herramientas moleculares aplicadas en ecología: Aspectos teóricos y prácticosMayer, M.P. (2013) Hsp70 Chaperone Dynamics and Molecular Mechanism. Trends in Biochemical Sciences, 38, 507-514. https://doi.org/10.1016/j.tibs.2013.08.001 10.1016/j.tibs.2013.08.00124012426https://doi.org/10.1016/j.tibs.2013.08.001Mayer, M.P.2013Hsp70 Chaperone Dynamics and Molecular MechanismTrends in Biochemical Sciences3810.1016/j.tibs.2013.08.00124012426Chatterjee, S. and Burns, T. (2017) Targeting Heat Shock Proteins in Cancer: A Promising Therapeutic Approach. International Journal of Molecular Sciences, 18, Article 1978. https://doi.org/10.3390/ijms18091978 10.3390/ijms1809197828914774https://doi.org/10.3390/ijms18091978Chatterjee, S.Burns, T.2017Targeting Heat Shock Proteins in Cancer: A Promising Therapeutic ApproachInternational Journal of Molecular Sciences18197810.3390/ijms1809197828914774Olarte-Saucedo, M., García-López, D.A., Ortiz-Letechipia, J., Palafox-Herrera, A., Reveles-Hernández, R.G., López-Luna, A., et al. (2020) Fragmentación de ADN y cambios en la expresión de las proteínas Hsp70, Hsp90 y P53 en la piel de ratones BALB/c expuestos a luz ultravioleta UV (UVA, UVB, UVC)—Dermatología Revista mexicana. Dermatología Revista mexicana, 64, 255-269.Olarte-Saucedo, M.Ortiz-Letechipia, J.Palafox-Herrera, A.Luna, A.UVA, UVB, U2020Fragmentación de ADN y cambios en la expresión de las proteínas Hsp70, Hsp90 y P53 en la piel de ratones BALB/c expuestos a luz ultravioleta UV (UVA, UVB, UVC)—Dermatología Revista mexicanaDermatología Revista mexicana64Tang, Y., Pan, A., Liu, Y. and Yin, L. (2021) The Diagnostic Value of Urine Heat Shock Protein 70 and Prostatic Exosomal Protein in Chronic Prostatitis. Journal of Clinical Laboratory Analysis, 35, e23778. https://doi.org/10.1002/jcla.23778 10.1002/jcla.2377833822413https://doi.org/10.1002/jcla.23778Tang, Y.Pan, A.Liu, Y.Yin, L.2021The Diagnostic Value of Urine Heat Shock Protein 70 and Prostatic Exosomal Protein in Chronic ProstatitisJournal of Clinical Laboratory Analysis3510.1002/jcla.2377833822413Calini, V., Urani, C. and Camatini, M. (2003) Overexpression of HSP70 Is Induced by Ionizing Radiation in C3H 10T1/2 Cells and Protects from DNA Damage. Toxicology in Vitro, 17, 561-566. https://doi.org/10.1016/s0887-2333(03)00116-4 10.1016/s0887-2333(03)00116-414599445https://doi.org/10.1016/s0887-2333(03)00116-4Calini, V.Urani, C.Camatini, M.2003Overexpression of HSP70 Is Induced by Ionizing Radiation in C3H 10T1/2 Cells and Protects from DNA DamageToxicology in Vitro23330310.1016/s0887-2333(03)00116-414599445Datkhile, K.D., Mukhopadhyaya, R., Dongre, T.K. and Nath, B.B. (2011) Hsp70 Expression in Chironomus ramosusExposed to γ Radiation. International Journal of Radiation Biology, 87, 213-221. https://doi.org/10.3109/09553002.2010.518215 10.3109/09553002.2010.51821521039329https://doi.org/10.3109/09553002.2010.518215Datkhile, K.D.Mukhopadhyaya, R.Dongre, T.K.Nath, B.B.2011Hsp70 Expression in Chironomus ramosus Exposed to γ RadiationInternational Journal of Radiation Biology8710.3109/09553002.2010.51821521039329Murakami, N., Kühnel, A., Schmid, T.E., Ilicic, K., Stangl, S., Braun, I.S., et al. (2015) Role of Membrane Hsp70 in Radiation Sensitivity of Tumor Cells. Radiation Oncology, 10, Article No. 149. https://doi.org/10.1186/s13014-015-0461-1 10.1186/s13014-015-0461-126197988https://doi.org/10.1186/s13014-015-0461-1Murakami, N.Schmid, T.E.Ilicic, K.Stangl, S.Braun, I.S.2015Role of Membrane Hsp70 in Radiation Sensitivity of Tumor CellsRadiation Oncology10No10.1186/s13014-015-0461-126197988Hahn, H.J., Youn, H.J., Cha, H.J., Kim, K., An, S. and Ahn, K.J. (2016) Single Low-Dose Radiation Induced Regulation of Keratinocyte Differentiation in Calcium-Induced HaCaT Cells. Annals of Dermatology, 28, 433-437. https://doi.org/10.5021/ad.2016.28.4.433 10.5021/ad.2016.28.4.43327489424https://doi.org/10.5021/ad.2016.28.4.433Hahn, H.J.Youn, H.J.Cha, H.J.Kim, K.An, S.Ahn, K.J.2016Single Low-Dose Radiation Induced Regulation of Keratinocyte Differentiation in Calcium-Induced HaCaT CellsAnnals of Dermatology2810.5021/ad.2016.28.4.43327489424Supriyadi, S. (2021) Priming Low-Dose Gamma Irradiation Increases Cellular Radioadaptation Response through the Induction of Hsp70 and SOD2. Atom Indonesia, 47, 99-104. https://doi.org/10.17146/aij.2021.1019 10.17146/aij.2021.1019https://doi.org/10.17146/aij.2021.1019Supriyadi, S.2021Priming Low-Dose Gamma Irradiation Increases Cellular Radioadaptation Response through the Induction of Hsp70 and SOD2Atom Indonesia4710.17146/aij.2021.1019Ibuki, Y., Hayashi, A., Suzuki, A. and Goto, R. (1998) Low-Dose Irradiation Induces Expression of Heat Shock Protein 70 mRNA and Thermo-and Radio-Resistance in Myeloid Leukemia Cell Line. Biological and Pharmaceutical Bulletin, 21, 434-439. https://doi.org/10.1248/bpb.21.434 10.1248/bpb.21.4349635495https://doi.org/10.1248/bpb.21.434Ibuki, Y.Hayashi, A.Suzuki, A.Goto, R.1998Low-Dose Irradiation Induces Expression of Heat Shock Protein 70 mRNA and Thermo-and Radio-Resistance in Myeloid Leukemia Cell LineBiological and Pharmaceutical Bulletin2110.1248/bpb.21.4349635495Durham, J. (2006) Concepts, Quantities, and Dose Limits in Radiation Protection Dosimetry. Radiation Measurements, 41, S28-S35. https://doi.org/10.1016/j.radmeas.2007.01.011 10.1016/j.radmeas.2007.01.011https://doi.org/10.1016/j.radmeas.2007.01.011Durham, J.Concepts, Q2006Concepts, Quantities, and Dose Limits in Radiation Protection DosimetryRadiation Measurements4110.1016/j.radmeas.2007.01.011Durán, A., Hian, S.K., Miller, D.L., Le Heron, J., Padovani, R. and Vano, E. (2013) Recommendations for Occupational Radiation Protection in Interventional Cardiology. Catheterization and Cardiovascular Interventions, 82, 29-42. https://doi.org/10.1002/ccd.24694 10.1002/ccd.2469423475846https://doi.org/10.1002/ccd.24694Hian, S.K.Miller, D.L.Heron, J.Padovani, R.Vano, E.2013Recommendations for Occupational Radiation Protection in Interventional CardiologyCatheterization and Cardiovascular Interventions8210.1002/ccd.2469423475846