Methods for determining individual radiosensitivity

Abstract

The present invention relates to the radiotherapy field. In particular, the invention relates to an in vitro method for determining the individual radiosensitivity of a patient. The inventors have in fact identified an individual-radiosensitivity-specific constitutional transcriptomic signature that makes it possible to assess whether a patient is radiosensitive or radiotolerant. The method according to the invention therefore comprises a step of measuring, in a biological sample obtained from a patient, the expression level of at least one gene from the group of 10 genes constituting this signature, namely KLF11, MIR4482, MT-TK, NEK1, PSPHP1, RNU5B-1, RNU6ATAC, RP11-159D12.8, STRN3 and TDG. The present invention makes it possible in particular to adapt the treatments of patients according to their radiosensitivity.

Description

METHODS FOR DETERMINING INDIVIDUAL RADIOSENSITIVITY Technical field

[0001] The present invention relates to the field of anticancer treatments, and particularly radiotherapy. The present invention relates in particular to in vitro methods for determining the individual radiosensitivity of patients. Prior art

[0002] Of the 19 million new cases of cancer diagnosed each year worldwide, half are treated with radiotherapy (RT) (IARC, 2020). 10 to 15% of treated patients are exposed to unusual acute toxicity, and 5 to 10% to late toxicity that can lead to sequelae that are sometimes fatal in the absence of therapeutic deviation (Mohanti et al., Supportive care in cancer 13.10, 2005, 775-780). In the case of breast cancer, this late toxicity can affect up to 18% of patients and results in particular in the development of radiation-induced skin fibrosis (RIF) in the area treated by RT taking the form of scleroatrophic radiodermatitis that can be complicated by necrosis (Sperk et al., Breast cancer research and treatment 135.1, 2012, 253-260).Other sequelae may occur in regional tissues irradiated at tumoricidal doses - notably the mammary gland (fibrosis / atrophy), muscles and soft tissues (fibrosis), vessels (lymphedema), nerves (plexitis, neuropathy), ribs (osteoradionecrosis), the ipsilateral lung (pneumonia, pulmonary fibrosis) or the heart (constrictive pericarditis, coronary stenosis, myocardial fibrosis, valvulopathy, conduction disturbance). Each individual is characterized by their own sensitivity to radiation or individual radiosensitivity (IRS). The molecular basis of this IRS remains largely misunderstood and, at present, no test allows its reliable measurement in routine use.

[0003] To prevent the onset of early and late toxicities, emphasis has been placed on improving RT techniques to reduce the volume of irradiated healthy tissue, and on the search for predictive biomarkers. The first proposed RSI tests are based on the quantification of radiation-induced fibroblast cell death, but their use in clinical practice has been limited by the need for a skin biopsy, cell culture time, cost, and lack of reproducibility. More recently, a blood test based on the rate of radiation-induced lymphocyte apoptosis has been proposed (international application published under reference WO2018 / 041960). The results of the latter, coupled with smoking status and the presence of hormone therapy, are very effective in identifying patients not at risk of RIF (NPV = 93.5%).On the other hand, they struggle to discriminate at-risk patients, showing a positive predictive value of only 20.9% and a specificity of 48.7%, notably due to the existence of confounding pathologies associated with lymphocyte apoptosis.

[0004] Understanding the origin of RSI, as well as the reliable and non-invasive prediction of RSI in each patient, are essential challenges in RT. Indeed, they could help the practitioner to personalize therapeutic decisions and in particular radiotherapy doses in order to optimize the individual therapeutic ratio. Thus, it would be possible to propose a dose escalation to the most radiotolerant patients (not at risk of IRF) or on the contrary a dose de-escalation, protective radiotherapy techniques (proton therapy, brachytherapy) or alternative local treatments dispensing with RT (non-conservative surgery) for the most radiosensitive patients (at risk of IRF). More than a cure, the radiotherapy of tomorrow must make it possible to guarantee a cure without after-effects for patients by integrating the IRF variable.

[0005] There is therefore a real need for a simple and reproducible method to determine the radiosensitivity of patients and thus predict their risk of developing radiation-induced toxicity such as radiation-induced fibrosis following radiotherapy treatment. Summary

[0006] The invention is defined by the claims.

[0007] The present inventors have succeeded in identifying a specific constitutional transcriptomic signature of individual radiosensitivity. This signature is 1 / transcriptomic, based on the detection of coding and non-coding RNAs, which, due to their diversity, are the molecules most likely to reflect a difference between 2 individuals, 2 / constitutional, because it allows individual radiosensitivity to be determined without requiring prior irradiation of the patient, it therefore allows the risk of radio-induced toxicity to be predicted before treatment, and 3 / specific in that it allows powerful discrimination between individuals.

[0008] The signature according to the present invention comprises 10 genes whose expression is correlated with individual radiosensitivity. These 10 genes therefore represent excellent biomarkers for determining individual radiosensitivity in a patient. Also in a first aspect, the present invention relates to an in vitro method for determining the individual radiosensitivity of a patient, said method comprising a step of measuring, in a biological sample obtained from said patient, the level of expression of at least 1 gene from the group of 10 genes consisting of RP11-159D12.8, MT-TK, KLF11, MIR4482, NEK1, PSPHP1, RNU5B-1, RNU6ATAC, STRN3 and TDG. The method according to the present invention makes it possible in particular to determine whether a patient is radiotolerant or radiosensitive, and therefore whether he is more at risk of developing radiation-induced toxicity such as radiation-induced fibrosis.The method according to the present invention can advantageously be carried out before the initiation of radiotherapy, and therefore from a biological sample obtained before treatment of the patient. Description of the embodiments

[0009] The specific signature of individual radiosensitivity according to the present invention was determined by performing an analysis of the blood transcriptome of a cohort of radiosensitive patients and a cohort of radiotolerant patients, treated with breast radiotherapy in the context of a clinical study (SPLICIRAD, NCT03000764). Based on this signature, a A predictive blood test has been developed. This blood test is non-invasive, fast, simple, and inexpensive. It is easy to use and automate, as the technique and equipment required for its performance are common in medical analysis laboratories.

[0010] The signature developed within the framework of the present invention is based on 10 different genes which are listed in Table 1 below. All the genes included in this signature are known to those skilled in the art. Their sequence as well as that of the corresponding transcripts are also known and easily accessible, for example on the Ensembl database.

[0011] Table 1: List of genes used as biomarkers of RSI in the context of the present invention.

[0012] The expression of the 10 genes mentioned above represents a specific constitutional transcriptomic signature of individual radiosensitivity. The present inventors have indeed succeeded in demonstrating that measuring the expression of at least one of these genes makes it possible to discriminate between radiosensitive patients and radiotolerant patients. Also, according to a first aspect, the present invention relates to an in vitro method for determining the individual radiosensitivity of a patient, said method comprising a step of measuring, in a biological sample obtained from said patient, the level of expression of at least 1 gene among the group of 10 genes consisting of RP11-159D12.8, MT-TK, KLF11, MIR4482, NEK1, PSPHP1, RNU5B-1, RNU6ATAC, STRN3 and TDG.

[0013] In the context of the method according to the present invention, the level of expression of 2, but also of 3, 4, 5, 6, 7, 8, 9 or even of the 10 genes listed above can be measured and make it possible to determine the individual radiosensitivity of the patient.

[0014] In the context of the present invention, said at least 1 gene may advantageously comprise the RNU6ATAC gene, the sole measurement of the expression level of which makes it possible to determine the individual radiosensitivity of patients with remarkable sensitivity and specificity as demonstrated in the experimental part below.

[0015] According to a particular embodiment, the method according to the invention comprises measuring the expression level of at least two genes among the 10 genes listed above. According to an even more particular embodiment, these at least two genes may for example comprise RP11-159D12.8 and MT-TK, RNU6ATAC and RP11 .159D12.8, MIR4482 and RP11 .159D12.8 or even NEK1 and KLF11 .

[0016] Those skilled in the art are familiar with numerous techniques that they use on a daily basis to determine the level of expression of a gene. The level of expression of a gene is typically determined by analyzing the RNA transcribed from this gene or the cDNA derived from this RNA. These nucleic acid molecules can typically be extracted from the biological sample obtained from the patient and analyzed by standard methods. They will typically be detected by amplification and / or hybridization with, for example, a probe. The isolated RNA can be subjected to several reverse transcription steps coupled with amplifications, for example by reverse transcriptase polymerase chain reaction (RT-PCR) using oligonucleotide primers specific to the genes of interest, or a part of these genes.

[0017] The measured expression level is typically normalized based on the expression of housekeeping genes. The expression level can typically be normalized to the expression of GAPDH and 5S genes.

[0018] According to a particular embodiment, the method according to the present invention comprises a step in which the expression level of the RSI signature genes listed above is compared to a reference value. This reference value is determined for each gene. It can be determined experimentally, empirically or theoretically and is set in order to obtain optimal specificity and selectivity. The expression level of the RSI signature genes listed above is typically used to calculate a score. The calculation of such a score is for example illustrated in the experimental part below. This score is then compared to a reference value in order to establish the radiosensitivity status of the patient. It is set in order to obtain optimal specificity and sensitivity.This reference value can be determined on the basis of results obtained in a control population, for example a population of known radiotolerant or known radiosensitive patients. A score above a threshold value determined on the basis of a population of radiosensitive and radiotolerant patients will be associated with a radiosensitive profile, while a score below this value will be associated with a radiotolerant profile.

[0019] Individual radiosensitivity, or ISR, represents the constitutional sensitivity to ionizing radiation of an individual's tissues within a population - their predisposition to develop significant tissue toxicity following desired (diagnostic / therapeutic) or unwanted (accidental) occupational or medical exposure depending on a radiation dose level and body volume exposed. In some patients, radiotherapy used in the loco-regional treatment of cancer can cause adverse effects in the short (early toxicity) or long (late toxicity) term that are more or less reversible. A patient will be more or less radiotolerant or radiosensitive depending on their individual radiosensitivity. The most radiotolerant patients have little or no risk of developing radiation-induced toxicity, while those who are more radiosensitive have a high risk of developing radiation-induced toxicities.Determining a patient's RSI therefore makes it possible to determine the risk for this patient of developing radiation-induced toxicity and therefore to determine whether a patient is rather radiotolerant or radiosensitive.

[0020] “Tissue-induced radiation toxicities” are ubiquitous and are based on a common pathophysiology leading to fibrosis. They are clinically apprehended from 6 months following the end of treatment in the high-dose irradiated area - and can have various clinical aspects depending on the anatomical location and the irradiated tissues: induration and thickening of the skin, muscle atrophy, joint ankylosis, lymphedema, mucosal atrophy, ulceration, fistula, stenosis of hollow organs, vascular stenoses / occlusions, neuropathy and pain.Depending on the anatomical sites, trismus, xerostomia, dysphonia, osteoradionecrosis can also be described in patients with head and neck tumors; myelitis, plexitis, interstitial pneumonitis, in patients with breast or lung tumors; infertility, plexitis, dyspareunia in patients with abdominopelvic tumors, glial radionecrosis, cognitive disorders, endocrinopathy. They include fibrosis, radiodermatitis, lymphedema, acute inflammation or neuropathies.

[0021] The method according to the present invention therefore makes it possible to predict the risk for a patient of developing any of these forms of toxicity. According to a preferred embodiment, the method according to the present invention makes it possible to predict the risk of a patient of developing radiation-induced fibrosis or "RIF". Unlike acute inflammation phenomena which can appear immediately or within 6 months following radiotherapy treatment, IRF is a "late" effect which appears more than 6 months without limitation of duration after radiotherapy.

[0022] For the purposes of the present invention, the "biological sample" may be any sample in which RNA can be detected. Typically, the sample is a fluid, a tissue, a cell sample, a biopsy, for example a skin biopsy, etc. The biological sample may particularly be a blood, serum or plasma sample obtained from the patient. In a preferred embodiment, the biological sample is a blood sample.

[0023] As indicated above, the signature according to the present invention is constitutional, that is to say that it represents an individual phenotypic characteristic and therefore does not require no prior irradiation to be able to be revealed. The method according to the present invention can therefore be carried out from a biological sample obtained before, during or after treatment of the patient by radiotherapy. According to a preferred embodiment, the biological sample is obtained from said patient before he is treated by radiotherapy.

[0024] The “patient” or “subject” is a human or an animal, for example a mammal. According to a preferred embodiment, the patient is a human.

[0025] Radiotherapy is a locoregional cancer treatment with curative or palliative intent consisting of targeting high-energy ionizing radiation on a tumorous or non-tumor lesion, benign or malignant, primary or secondary, existing or operated on, or even an area at risk - in order to primarily inactivate pathological cells. Radiotherapy can be delivered using particle accelerators (external radiotherapy). Equivalent doses of 20 to 80 grays (Gy) are typically delivered (conventional fractionation - daily sessions of 1.8 to 2.2 Gy spaced at least 6 hours apart).A radioactive therapeutic agent can also be administered in direct contact with the tumor in the body: we distinguish i- brachytherapy during which unsealed radioactive sources are introduced directly into or in the immediate vicinity of the areas to be treated inside the body; thus iodine 125 is used in brachytherapy in the treatment of prostate cancer or iridium 192 for uterine cancers - and ii- vectorized internal radiotherapy (or metabolic) during which a radiopharmaceutical substance is administered orally or by intravenous injection and will attach to the cancer cells; we can cite iodine-131, lutetium-177, yttrium-90, holmium-166, radium-223, strontium-89 and samarium-153.

[0026] According to one embodiment, the method according to the present invention can be carried out from a sample obtained from a healthy patient, and therefore who does not suffer from a pathology requiring treatment by radiotherapy. In this context, the method according to the present invention makes it possible to determine whether the patient will have a risk of developing radiation-induced toxicity if he were to one day receive treatment by radiotherapy or be exposed to ionizing radiation.

[0027] According to another embodiment, the method according to the present invention can be carried out from a sample obtained from a patient who suffers from a pathology that will require radiotherapy treatment, such as cancer. According to this embodiment, the method according to the present invention makes it possible to determine whether the patient is at risk of developing radiation-induced toxicity and therefore makes it possible to adapt the treatment.If it is determined that the patient is rather radiosensitive, and therefore at risk of developing radiation-induced toxicity, then it will be possible to reduce the doses of radiation received, to favor internal radiotherapy techniques such as proton therapy or brachytherapy which are less likely to cause toxicities than external radiotherapy, or to propose a therapeutic alternative such as, for example, the use of anticancer treatments other than radiotherapy, such as surgery, chemotherapy or immunotherapy (see Figure 2 of Pereira et al., Cancers (Basel) 14.24, 2022,. 6252). Conversely, if it is determined that the patient is rather radiotolerant, and therefore at low risk of developing radiation-induced toxicity, then it will be possible to increase the doses of radiation received.

[0028] The present disclosure therefore also relates to a method of treating cancer in which the radiosensitivity of a patient suffering from cancer is determined according to the method of the present invention, and in which: when the patient is identified as being radiosensitive, the treatment consists of surgery, chemotherapy, immunotherapy and / or radiotherapy such as proton therapy, brachytherapy or radiotherapy with doses lower than those received in a standard manner for the treatment of this cancer; when the patient is identified as being radiotolerant, the treatment comprises radiotherapy, possibly with doses higher than those received in a standard manner for the treatment of this cancer.

[0029] The present invention also relates to a radiotherapeutic agent for use in the treatment of cancer in a patient, wherein said patient has been identified as being radiotolerant according to the method of the present invention.

[0030] A "radiotherapeutic agent" may be any agent known to those skilled in the art for use in external or internal radiotherapy. A radiotherapeutic agent may, for example, be such as those administered in the context of brachytherapy (iodine-125, Iridium 192) or systemic therapy with beta-minus or alpha emitting radioisotope such as iodine-131, gallium-68, lutetium-177, phosphorus-32, yttrium-90, holmium-166, radium-223, strontium-89, samarium-153, actinium-225, erbium-169, rhenium-186, bismuth-212 (vectorized internal radiotherapy or metabolic radiotherapy).

[0031] The “cancer” to be treated is any primary or metastatic cancer that can be treated by radiotherapy in adults and children. In particular, this cancer is selected from the group consisting of breast cancer, prostate cancer, lung cancer, cancer of the upper aerodigestive tract (ENT cancer), tumors of the central nervous system, sarcomas, lymphomas, cervical cancer, endometrial cancer, cancer of the rectum / anal canal, bladder cancer, pancreatic cancer, liver cancer, stomach cancer, esophageal cancer, prostate cancer, testicular cancer, neuroendocrine tumors, thyroid cancer. In a particular embodiment, said cancer is breast cancer.

[0032] The present invention is presented in more detail in the examples below. These examples are provided for illustrative purposes only and should not be construed as limiting the scope of the present invention. Brief description of the drawings

[0033] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analyzing the attached drawings, in which:

[0034] Figure 1 illustrates the qRT-PCR validation of the variation in the expression of each of the 10 genes composing the blood signature in blood samples from the SPLICIRAD clinical study (NCT03000764). RS = radiosensitive; RT = radiotolerant. The Mann-Whitney-Wilcoxon statistical test was used to calculate the p-value: *p < 0.15; **p < 0.05

[0035] Figure 2 illustrates the effectiveness of the proposed model for discriminating radiosensitive and radiotolerant individuals based on the expression of the MT-TK and RP11-159D12.8 genes alone (Panels A and C) or of all 10 genes in the signature (Panels B and D). Panels A and B: model-predicted score for patients in the SPLICIRAD study (RS = radiosensitive; RT = radiotolerant). Panels C and D: Receiver Operating Characteristic (ROC) curve demonstrating the specificity and sensitivity of the proposed models. Examples

[0036] 1. Identification of a blood transcriptomic signature of Individual Radiosensitivity (IRS)

[0037] Since RSI is constitutional, it is possible to identify an individual's RSI from any of their tissues. Blood, which is easily accessible and analyzable, was chosen as the biological source because our ultimate goal was to develop a non-invasive predictive RSI test that could be implemented in all analysis laboratories. The model of radiation-induced skin fibrosis, a frequent late toxicity occurring after breast cancer treatment with radiotherapy, was taken as a radiotoxicity model for the development of this signature. RNAs were extracted from PaxGene™ RNA Blood tubes of radiosensitive or radiotolerant patients in the SPLICIRAD clinical study (NCT03000764) and hybridized to Affymetrix Clariom™ D arrays. These high-definition arrays cover not only the exons of coding and non-coding transcripts, i.e., 670,402 exons, but also known exon-exon junctions (339,146 junctions).A quantitative bioinformatics analysis was then performed before a functional analysis on R and on the DAVID platform (Database for Annotation, Visualization and Integrated Discovery). Based on the transcriptome analysis of patients in these 2 groups, a blood signature was identified. It comprises 10 genes (Table 1). Each of the 10 genes is significantly differentially expressed between radiosensitive and radiotolerant patients (Figure 1). The measurement of the expression normalized to the expression of GAPDH mRNA and 5S rRNA of at least 1 gene among the signature of 10, in particular the RNU6ATAC gene, allows very good discrimination of radiosensitive and radiotolerant patients with a sensitivity of 80%, a specificity of 80% and an AUC of 0.83 (Table 2). The predictive performances of each of the 10 genes and of all possible combinations of 2 genes among the 10 are described in Table 2.As demonstrated in this table, measuring the expression of at least one of these ten genes is sufficient and effective in determining a patient's individual radiosensitivity. This table shows in particular that the. discrimination of radiosensitive and radiotolerant patients by measuring gene expression: - MT-TK and RP11-159D12.8 is performed with a sensitivity of 90%, a specificity of 100% and an AUC of 0.98 (Figure 2A / 2C); - RNU6ATAC and RP11 .159D12.8 is performed with a sensitivity of 100%, a specificity of 100% and an AUC of 1; - premiR4482 and RP11 .159D12.8 with a sensitivity of 90%, a specificity of 90% and an AUC of 0.98; - NEK1 and KLF11 with a sensitivity of 80%, a specificity of 90% and an AUC of 0.97; while the measurement of all 10 genes of the signature allows perfect discrimination of radiosensitive and radiotolerant patients with a sensitivity of 100%, a specificity of 100% and an AUC of 1 (Figure 2B / 2D).

[0038] [Table 2]: Discrimination performance of radiosensitive and radiotolerant individuals by measuring the expression of each of the 10 genes and all possible combinations of 2 genes among the 10 genes in the blood signature. The name of the gene or gene combination, as well as the sensitivity, specificity and AUC are indicated.

[0039] [Table 3]: List of blood signature genes. The gene name and the nature of the gene product (coding or non-coding RNA) are indicated.

[0040] The test thus developed is distinguished by its pathophysiological relevance (human model, realistic experimental conditions, integrative approach focused on molecular events) and does not require prior ex-vivo irradiation. Indeed, although the data presented here were obtained from patients who received a dose of radiotherapy since their individual radiosensitivity phenotype had to be determined before the study, the data available today demonstrate that the signature identified here is not affected by irradiation. First, the patients' transcriptome was analyzed from blood samples taken 5 years post-irradiation and it was verified that the expression of the genes in this signature does not vary in response to irradiation (transcriptomic analysis after 2Gy irradiation performed ex-vivo on primary fibroblast cultures from patients in the SPLICI-Rad study).Second, blood cells, given their lifespan (from a few hours to a few months), had all been renewed at the time of collection and blood cell progenitors are located in areas "protected" by irradiation schedules because these are organs at significant risk of toxicity if affected. Finally, the lymphocyte apoptosis test (Azria et al., EBioMedicine 2.12, 2015: 1965-1973), although developed on blood samples taken post-irradiation, confirmed its effectiveness by similar results on blood samples taken before radiotherapy.

[0041] The test developed within the framework of the present invention makes it possible to determine individual radiosensitivity before irradiation with high selectivity and specificity.

[0042] Embodiment of the method according to the present invention

[0043] The PAXgene® Blood RNA Kit is used for the purification of intracellular RNA from whole blood collected in the PAXgene® Blood RNA Tube. PAXgene® Blood RNA Tubes (BRT) contain a specific reagent based on patented RNA stabilization technology. This reagent protects RNA molecules from degradation by RNases and minimizes ex vivo changes in gene expression. PAXgene® BRTs ensure stabilization of cellular RNA for up to 3 days at 18-25°C, up to 5 days at 2-8°C, and at least 11 years when stabilized blood is stored at -20°C or -70°C. This system allows the preparation of good quality purified intracellular RNA that can be used for RT-PCR-based molecular diagnostic tests.

[0044] The extracted RNAs are then measured by spectrophotometry at 260 nm. Contamination by proteins or phenolic compounds / salts is estimated by measuring the absorbance ratios 260 / 280 and 260 / 230, respectively. If these ratios are unsatisfactory (ratios 1.7), a phenol-chloroform extraction, followed by precipitation with absolute ethanol in the presence of 0.15 M sodium acetate is carried out in order to eliminate phenol and protein residues and to optimize the quality of total RNAs. The quality of the RNAs as well as the non-contamination by genomic DNA is evaluated by capillary electrophoresis.

[0045] The reverse transcription (RT) reaction is performed on a minimum of 50 ng of total RNA using a mixture of random primers and (dT)18 (Superscript™ IV Vilo Master Mix, Invitrogen) according to the supplier's protocol.

[0046] The expression of blood signature genes is analyzed by real-time PCR based on SYBR Green chemistry (ITaq Master Mix, Bio-Rad) according to the supplier's protocol. The cDNAs produced by reverse transcription are diluted 1 / 10 or 1 / 100 depending on the abundance of the transcripts of interest. The detected fluorescent signal allows a quantitative measurement of the exponential accumulation of the product during the different PCR cycles. A standard curve is produced for each primer pair and the signal of the housekeeping genes GAPDH and 5S is used to normalize the data. All amplifications are performed in technical triplicate. Negative controls, H2O control and non-reverse transcribed control (RT-), are performed in parallel.

[0047] The RSI status of the analyzed patient can be established according to the following method:

[0048] Modeling of the radiosensitivity status of patients using logistic regression taking into account at least the normalized expression levels of the RP11 .159D12.8 and MT-TK genes, which can be supplemented by those of the genes listed in Table 2 and other relevant clinical variables. This model makes it possible to establish a score, the discrimination threshold between the two patient phenotypes of which is set using its Youden index. Taking into account only the RP11 .159D12.8 and MTTK genes, the score is as follows: With A = 25.523 - 25.501 * ÆP11.159D12.8 - 5.214 * MTTK In this case, the threshold for discriminating between radiosensitive patients and radiotolerant patients is 0.681: If the score is > 0.681, then the patient is predicted to be radiosensitive. - If the score is < 0.681, then the patient is predicted to be radiotolerant.

[0049] Taking into account the RP11 .159D12.8 and MTTK genes, as well as the 8 other genes in the signature, the score is as follows: With A = 74.082 - 144.005 * STRN3 - 150.727 * ÆP11.159D12.8 - 20.528 * MTTK + 0.681 * premiRAA82 + 100.486 * NEK1 + 127.447 * TDG - 37.488 * RNU6ATAC + 47.995 * RNU5B + 626.016 * KLF11 - 88.642 * PSPHP1 In this case, the threshold for discriminating between radiosensitive patients and radiotolerant patients is 0.5: If the score is > 0.5, then the patient is predicted to be radiosensitive. - If the score is < 0.5, then the patient is predicted to be radiotolerant.

Claims

Claims

1. An in vitro method for determining the individual radiosensitivity of a patient, said method comprising a step of measuring, in a biological sample obtained from said patient, the expression level of at least 1 gene from the group of 10 genes consisting of RP11-159D12.8, MT-TK, KLF11, MIR4482, NEK1, PSPHP1, RNU5B-1, RNU6ATAC, STRN3 and TDG.

2. The method of claim 1, wherein the expression level of at least RNU6ATAC is measured.

3. The method of claim 1, wherein the expression level of at least 2 genes among the group of 10 genes is measured.

4. The method of claim 3, wherein said at least 2 genes comprise RP11-159D12.8 and MT-TK, RNU6ATAC and RP11.159D12.8, MIR4482 and RP11.159D12.8 or NEK1 and KLF11.

5. The method of any one of claims 1 to 4, wherein the expression level of the 10 genes is measured.

6. A method according to any one of claims 1 to 5, wherein said method makes it possible to determine the risk of developing radiation-induced fibrosis.

7. A method according to any one of claims 1 to 6, wherein said biological sample is a blood sample.

8. A method according to any one of claims 1 to 7, wherein said biological sample is obtained before treatment of the patient by radiotherapy.

9. A method according to any one of claims 1 to 8, wherein the patient is human.

10. A method according to any one of claims 1 to 9, wherein said patient is suffering from cancer.

11. The method of claim 10, wherein said cancer is breast cancer.

12. A radiotherapeutic agent for use in the treatment of cancer in a patient, wherein said patient has been identified as being radiotolerant according to the method of any one of claims 1 to 11.

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