Exploring the utility of FTS as a bonafide binding partner for EGFR: A potential drug target for cervical cancer.

Establishment of human papilloma virus (HPV) infection and its progression to cervical cancer (CC) requires the participation of epidermal growth factor (EGF) receptor (EGFR) and fused toes homolog (FTS). This review is an attempt to understand the structure-function relationship between FTS and EGFR as a tool for the development of newer CC drugs. Motif analysis was performed using national center for biotechnology information (NCBI), kyoto encyclopedia of genes and genomes (KEGG), simple modular architecture research tool (SMART) and multiple expectation maximizations for motif elicitation (MEME) database. The secondary and tertiary structure prediction of FTS was performed using DISOPRED3 and threading assembly, respectively. A positive correlation was found between the transcript levels of FTS and EGFR. Amino acids responsible for interaction between EGFR and FTS were determined. The nine micro-RNAs (miRNAs) that regulates the expression of FTS were predicted using Network Analyst 3.0 database. hsa-miR-629-5p and hsa-miR-615-3p are identified as significant positive and negative regulators of FTS gene expression. This review opens up new avenues for the development of CC drugs which interfere with the interaction between FTS and EGFR.

Definitive radiotherapy in patients with clinical T1N0M0 esophageal squamous cell carcinoma: A multicenter retrospective study (KROG 21-10).

PURPOSE: To assess the failure pattern and analyze the treatment scheme of definitive radiation therapy (RT) for T1N0M0 esophageal squamous cell carcinoma (ESCC). METHODS: We performed a multi-institutional retrospective analysis in T1N0M0 ESCC patients who underwent definitive RT from 2010 to 2019. Patterns of failure were demonstrated as in-, and out-field locoregional, and distant metastasis. In the analysis, freedom-from locoregional recurrence (FFLRR) and their association with clinicopathologic factors were evaluated. Propensity score matching in cT1b patients was done. RESULTS: 168 patients were included with a median follow-up of 34.0 months, and 26 cT1a, 116 cT1b disease. The rates of 3-year all and locoregional recurrence for cT1a were 30.5% and 24.1% and those for cT1b were 27.1% and 25.9%, respectively. Among 116 cT1b patients, 69 patients received elective nodal irradiation (ENI) and 47 received involved field irradiation (IFI). After propensity score matching, the 3-year FFLRR rate was 84.5%. There was no difference between ENI and IFI in FFLRR (P = 0.831) and OS (P = 0.525). The 3-year FFLRR was 83.8% (95% Confidence interval (CI), 61.8-93.8%) in IFI group and 85.3% (95% CI, 65.1-94.3%) in ENI group. In multivariate analysis, concurrent chemotherapy use was marginally associated with FFLRR (Hazard ratio, 0.16; P = 0.064). CONCLUSION: cT1a patients who cannot receive endoscopic resection showed similar failure rates as cT1b patients, questioning the staging accuracy and raised the need for thorough treatment like chemoradiotherapy. In cT1b patients, IFI with 50 to 60 Gy and concurrent chemotherapy could be reasonable.

Evaluation of Efficacy and Safety Using Low Dose Radiation Therapy with Alzheimer's Disease: A Protocol for Multicenter Phase II Clinical Trial.

BACKGROUND: Alzheimer's disease (AD), the most common cause of dementia, is a neurodegenerative disease resulting from extracellular and intracellular deposits of amyloid-ß (Aß) and neurofibrillary tangles in the brain. Although many clinical studies evaluating pharmacological approaches have been conducted, most have shown disappointing results; thus, innovative strategies other than drugs have been actively attempted. OBJECTIVE: This study aims to explore low-dose radiation therapy (LDRT) for the treatment of patients with AD based on preclinical evidence, case reports, and a small pilot trial in humans. METHODS: This study is a phase II, multicenter, prospective, single-blinded, randomized controlled trial that will evaluate the efficacy and safety of LDRT to the whole brain using a linear accelerator in patients with mild AD. Sixty participants will be randomly assigned to three groups: experimental I (24 cGy/6 fractions), experimental II (300 cGy/6 fractions), or sham RT group (0 cGy/6 fractions). During LDRT and follow-up visits after LDRT, possible adverse events will be assessed by the physician's interview and neurological examinations. Furthermore, the effectiveness of LDRT will be measured using neurocognitive function tests and imaging tools at 6 and 12 months after LDRT. We will also monitor the alterations in cytokines, Aß42/Aß40 ratio, and tau levels in plasma. Our primary endpoint is the change in cognitive function test scores estimated by the Alzheimer's Disease Assessment Scale-Korea compared to baseline after 6 months of LDRT. CONCLUSIONS: This study is registered at ClinicalTrials.gov [NCT05635968] and is currently recruiting patients. This study will provide evidence that LDRT is a new treatment strategy for AD.

The effects of low-dose radiation therapy in patients with mild-to-moderate Alzheimer's dementia: an interim analysis of a pilot study.

PURPOSE: We aimed to determine whether low-dose radiotherapy (LDRT) is effective in patients with Alzheimer disease (AD). MATERIALS AND METHODS: We included patients according to the following criteria: probable Alzheimer's dementia according to the New Diagnostic Criteria for Alzheimer's Disease; confirmation of amyloid plaque deposits on baseline amyloid positron emission tomography (PET); a Korean Mini-Mental State Examination 2nd edition (K-MMSE-2) score of 13-26; and a Global Clinical Dementia Rating (CDR) score of 0.5-2 points. LDRT was performed six times at 0.5 Gy each. Post-treatment cognitive function tests and PET-CT examinations were performed to evaluate efficacy. The medication for AD treatment was maintained throughout the study period. RESULTS: At 6 months after LDRT, neurological improvement was seen in 20% of patients. Patient #2 showed improvement in all domains of the Seoul Neuropsychological Screening Battery II (SNSB-II). Moreover, the K-MMSE-2 and Geriatric Depression Score-Short Form scores improved from 20 to 23 and from 8 to 2, respectively. For patient #3, the CDR score (sum of box score) improved from 1 (4.0) to 1 (3.5) at 3 months follow-up. Moreover, the Z scores for language and related functions, memory, and frontal executive function improved to -2.56, -1.86, and -1.32, respectively at the 6-month follow-up. Two patients complained of mild nausea and mild hair loss during LDRT, which improved after treatment. CONCLUSION: One of the five patients with AD treated with LDRT experienced a temporary improvement in SNSB-II. LDRT is tolerable in patients with AD. We are currently under follow-up and will conduct cognitive function tests after 12 months after LDRT. A large-scale randomized controlled trial with a longer follow-up period is warranted to determine the effect of LDRT on patients with AD.

Fused toes homolog, a potential molecular regulator of human papillomavirus type 16 E6 and E7 oncoproteins in cervical cancer.

Human papillomavirus type 16 (HPV16) plays a major role in the development of cervical cancer. The oncogenic potential of HPV16 is attributed to E6 and E7 oncoproteins. Here, we investigated the relationship between fused toes homolog (FTS) and HPV16 E6 and E7 in cervical cancer cells. HPV16-positive CaSki and SiHa cell lines were used for in vitro studies. FTS silencing was performed using a small interfering RNA (siRNA)-based approach, and western blotting was performed to determine the protein expression of tumor suppressors and cell survival markers. Immunoprecipitation, immunofluorescence, in silico analysis, and immunohistochemistry were performed to determine the interaction between, and intracellular co-localization of, FTS and both the E6 and E7 proteins. Silencing of FTS reduced the expression of the E6 and E7 proteins in cervical cancer cell lines and conversely increased the expression of the tumor suppressor proteins p53 and retinoblastoma protein. However, the primary transcripts of HPV16 E6 and E7 were unaffected by FTS silencing; furthermore, FTS transcription was unaffected by silencing of either E6 or E7, suggesting their interaction occurs post-translationally. Immunofluorescence and immunohistochemistry analysis demonstrated co-localization of FTS with the HPV16 E6 and E7 proteins, while immunoprecipitation results suggested that FTS interacts with both E6 and E7. Furthermore, in silico structural analysis identified putative residues involved in the binding of FTS with E6 and E7. Taken together, these results show that FTS affects both HPV16 E6 and E7 oncogenes in cervical cancer. We propose FTS as a target for the prevention of cervical cancer development and progression.

Phyto-targeting the CEMIP Expression as a Strategy to Prevent Pancreatic Cancer Metastasis.

INTRODUCTION: Metastasis of primary pancreatic cancer (PC) to adjacent or distant organs is responsible for the poor survival rate of affected individuals. Chemotherapy, radiotherapy, and immunotherapy are currently being prescribed to treat PC in addition to surgical resection. Surgical resection is the preferred treatment for PC that leads to 20% of 5-year survival, but only less than 20% of patients are eligible for surgical resection because of the poor prognosis. To improve the prognosis and clinical outcome, early diagnostic markers need to be identified, and targeting them would be of immense benefit to increase the efficiency of the treatment. Cell migration-inducing hyaluronan-binding protein (CEMIP) is identified as an important risk factor for the metastasis of various cancers, including PC. Emerging studies have pointed out the crucial role of CEMIP in the regulation of various signaling mechanisms, leading to enhanced migration and metastasis of PC. METHODS: The published findings on PC metastasis, phytoconstituents, and CEMIP were retrieved from Pubmed, ScienceDirect, and Cochrane Library. Computational tools, such as gene expression profiling interactive analysis (GEPIA) and Kaplan-Meier (KM) plotter, were used to study the relationship between CEMIP expression and survival of PC individuals. RESULTS: Gene expression analysis using the GEPIA database identified a stupendous increase in the CEMIP transcript in PC compared to adjacent normal tissues. KM plotter analysis revealed the impact of CEMIP on the overall survival (OS) and disease-free survival (DFS) among PC patients. Subsequently, several risk factors associated with PC development were screened, and their ability to regulate CEMIP gene expression was analyzed using computational tools. CONCLUSION: The current review is focused on gathering information regarding the regulatory role of phytocomponents in PC migration and exploring their possible impact on the CEMIP expression.

A review on the role of epidermal growth factor signaling in the development, progression and treatment of cervical cancer.

The sub-committee constituted by the Indian Council of Medical Research (ICMR) for the management of cervical cancer (CC) detailed in the consensus document (2016) reported CC as a significant cause of morbidity and mortality in women. The incidence of an increase in CC and associated mortality in women is a major cause of cancer. To date, human papilloma viral (HPV) infection accounts for more than 99% of CC. However, there are individuals infected with HPV do not develop CC. There is a greater correlation between HPV infection and upregulation of the epidermal growth factor receptor (EGFR) signaling cascade during the initiation, sustenance, and progression of CC. Therefore, EGFR is often targeted to treat CC using tyrosine kinase inhibitors (TKIs) and monoclonal antibodies (mAB). The current review analyzed the existing clinical/pre-clinical studies and the significance of EGFR abundance using the Kaplan-Meier (KM) survival plot analysis for disease-free survival (DFS) and overall survival (OS). We performed a series of bioinformatics analyses to screen the crucial role of the EGFR gene in CC. Further, different transcription factors that are dysregulated due to EGFR abundance and their relevance were determined using computational tools in this review. Endogenous microRNAs (miRNA) that undergo changes due to alterations in EGFR during CC were identified using computational database and consolidated the information obtained with the published in the area of miRNA and EGFR with special reference to the initiation, sustenance and progression of CC. The current review aims to consolidate contemporary approaches for targeting CC using EGFR and highlight the current role of miRNA and genes that are differently regulated during CC involving EGFR mutations. Potential resistance to the available EGFR therapies such as TKIs and mABs and the need for better therapies are also extensively reviewed for the development of newer therapeutic molecules with better efficacy.

Silencing of Fused Toes Homolog (FTS) Increases Radiosensitivity to Carbon-Ion Through Downregulation of Notch Signaling in Cervical Cancer Cells.

The effects of Carbon ion radiation (C-ion) alone or in combination with fused toes homolog (FTS) silencing on Notch signaling were investigated in uterine cervical cancer cell lines (ME180 and CaSki). In both cell lines, upon irradiation with C-ion, the expression of Notch signaling molecules (Notch1, 2, 3 and cleaved Notch1), γ-secretase complex molecules and FTS was upregulated dose-dependently (1, 2 and 4 Gy) except Notch1 in ME180 cells where the change in expression was not significant. However, overexpression of these molecules was attenuated upon silencing of FTS. The spheroid formation, expression of stem cell markers (OCT4A, Sox2 and Nanog) and clonogenic cell survival were reduced by the combination as compared to FTS silencing or C-ion irradiation alone. Additionally, immunoprecipitation and immunofluorescence assay revealed interaction and co-localization of FTS with Notch signaling molecules. In conclusion, FTS silencing enhances the radio-sensitivity of the cervical cancer cells to C-ion by downregulating Notch signaling molecules and decreasing the survival of cancer stem cells.

Virtual randomized study comparing lobectomy and particle beam therapy for clinical stage IA non-small cell lung cancer in operable patients.

To the best of our knowledge there have been no randomized controlled trials comparing lobectomy-a standard treatment for patients with early-stage non-small cell lung cancer (NSCLC)-and particle beam therapy (PBT), the best performing existing radiotherapy. We conducted a virtual randomized trial in medically operable patients with stage IA NSCLC to compare lobectomy and PBT effectiveness. A Markov model was developed to predict life expectancy after lobectomy and PBT in a cohort of patients with stage IA NSCLC. Ten thousand virtual patients were randomly assigned to each group. Sensitivity analyses were performed as model variables and scenarios changed to determine which treatment strategy was best for improving life expectancy. All estimated model parameters were determined using variables extracted from a systematic literature review of previously published articles. The preferred strategy differed depending on patient age. In young patients, lobectomy showed better life expectancy than that of PBT. The difference in life expectancy between lobectomy and PBT was statistically insignificant in older patients. Our model predicted lobectomy as the preferred strategy when operative mortality was under 5%. However, the preferred strategy changed to PBT if operative mortality post lobectomy was over 5%. For medically operable patients with stage IA NSCLC, our Markov model revealed the preferred strategy of lobectomy or PBT regarding operative mortality changed with varying age and comorbidity. Until randomized controlled trial results become available, we hope the current results will provide a rationale background for clinicians to decide treatment modalities for patients with stage IA NSCLC.

Radioprotective effects of Cryptosporidium parvum lysates on normal cells.

Two fractions, small and big (CpL-S, CpL-B), from Cryptosporidium parvum lysate (CpL) were prepared and its radioprotective activity was evaluated on normal cells. Both fractions improved cell viability of normal cells in a dose-dependent manner. 20 µg CpL-S and CpL-B improved cell viability of 10 Gy irradiated COS-7 cells by 38% and 34% respectively, while in HaCat cells 16% and 18% improved cell viability was observed, respectively. CpL-S scavenged IR-induced ROS more effectively compared to the CpL-B, 50% more in COS-7 cells and 15% more in HaCat cells. There was a significant reduction of γH2AX, Rad51, and pDNA-PKcs foci in CpL-S treated cells compared to control or CpL-B group at an early time point as well as late time point. In 3D skin tissue, CpL-S reduced the number of γH2AX positive cells by 31%, compared to control, while CpL-B reduced by 9% (p < 0.005) at 1 h post 10 Gy irradiation and 22% vs 6% at 24 h post-IR (p < 0.005). Taken together, CpL-S significantly improved cell viability and prevented radiation-induced DNA damage in normal cells as well as 3D skin tissues by effectively scavenging ROS generated by ionizing radiation. CpL-S can be a candidate for radioprotector development.

Dummy Run of Quality Assurance Program before Prospective Study of Hippocampus-Sparing Whole-Brain Radiotherapy and Simultaneous Integrated Boost for Multiple Brain Metastases from Non-small Cell Lung Cancer: Korean Radiation Oncology Group (KROG) 17-06 Study.

PURPOSE: Lung Cancer Subcommittee of Korean Radiation Oncology Group (KROG) has recently launched a prospective clinical trial (KROG 17-06) of hippocampus-sparing whole brain radiotherapy (HS-WBRT) with simultaneous integrated boost (SIB) in treating multiple brain metastases from non-small cell lung cancer. In order to improve trial quality, dummy run studies among the participating institutions were designed. This work reported the results of two-step dummy run procedures of the KROG 17-06 study. MATERIALS AND METHODS: Two steps tested hippocampus contouring variability and radiation therapy planning compliance. In the first step, the variation of the hippocampus delineation was investigated for two representative cases using the Dice similarity coefficients. In the second step, the participating institutions were requested to generate a HS-WBRT with SIB treatment plan for another representative case. The compliance of the treatment plans to the planning protocol was evaluated. RESULTS: In the first step, the median Dice similarity coefficients of the hippocampus contours for two other dummy run cases changed from 0.669 (range, 0.073 to 0.712) to 0.690 (range, 0.522 to 0.750) and from 0.291 (range, 0.219 to 0.522) to 0.412 (range, 0.264 to 0.598) after providing the hippocampus contouring feedback. In the second step, with providing additional plan priority and extended dose constraints to the target volumes and normal structures, we observed the improved compliance of the treatment plans to the planning protocol. CONCLUSION: The dummy run studies demonstrated the notable inter-institutional variability in delineating the hippocampus and treatment plan generation, which could be decreased through feedback from the trial center.

Silencing of FTS increases radiosensitivity by blocking radiation-induced Notch1 activation and spheroid formation in cervical cancer cells.

Increasing evidence(s) suggests that cancer stem cells (CSC) in tumours contribute to radio-resistance and recurrence. Notch plays an important role in the maintenance of CSC in many cancers including cervical cancer. Previously, we have reported the role of Fused Toes Homolog (FTS) in conferring radioresistance in cervical cancer cells in vitro and human subjects. The present study investigated the regulatory role of FTS in Notch signaling and maintenance of CSC upon irradiation of cervical cancer cells. The expression of Notch1, 2, 3, cleaved Notch1 and its downstream target Hes1, and spheroid formation was increased by irradiation. Silencing of FTS prevented the radiation-induced increase in the expression of Notch signaling molecules and spheroid formation. Immunoprecipitation showed FTS binds Notch1 and Hes1. Also in silico structural analysis identified putative residues responsible for the binding between FTS and Notch1. Spheroid formation and the expression of CSC markers, Nanog, Oct4A and Sox2 were greatly reduced by combining silencing of FTS and radiation. Taken together, these results suggest that FTS is involved in the regulation of irradiation-induced Notch signaling and CSC activation and can be used as a target to increase radiosensitivity in cervical cancer.

Assessment of the accuracy and stability of frameless gamma knife radiosurgery.

The aim of this study was to assess the accuracy and stability of frameless gamma knife radiosurgery (GKRS). The accuracies of the radiation isocenter and patient couch movement were evaluated by film dosimetry with a half-year cycle. Radiation isocenter assessment with a diode detector and cone-beam computed tomography (CBCT) image accuracy tests were performed daily with a vendor-provided tool for one and a half years after installation. CBCT image quality was examined twice a month with a phantom. The accuracy of image coregistration using CBCT images was studied using magnetic resonance (MR) and computed tomography (CT) images of another phantom. The overall positional accuracy was measured in whole procedure tests using film dosimetry with an anthropomorphic phantom. The positional errors of the radiation isocenter at the center and at an extreme position were both less than 0.1 mm. The three-dimensional deviation of the CBCT coordinate system was stable for one and a half years (mean 0.04 ± 0.02 mm). Image coregistration revealed a difference of 0.2 ± 0.1 mm between CT and CBCT images and a deviation of 0.4 ± 0.2 mm between MR and CBCT images. The whole procedure test of the positional accuracy of the mask-based irradiation revealed an accuracy of 0.5 ± 0.6 mm. The radiation isocenter accuracy, patient couch movement accuracy, and Gamma Knife Icon CBCT accuracy were all approximately 0.1 mm and were stable for one and a half years. The coordinate system assigned to MR images through coregistration was more accurate than the system defined by fiducial markers. Possible patient motion during irradiation should be considered when evaluating the overall accuracy of frameless GKRS.

Simultaneous Molecular Detection of Cryptosporidium and Cyclospora from Raw Vegetables in Korea.

Cryptosporidium and Cyclospora are well-known coccidian protozoa that can cause waterborne and foodborne diarrheal illnesses. There have been a few reports regarding contamination in different vegetables with Cryptosporidium, but no data are available regarding the sources of Cyclospora infections in Korea. In the present study, we collected 6 kinds of vegetables (perilla leaves, winter-grown cabbages, chives, sprouts, blueberries, and cherry tomatoes) from July 2014 to June 2015, and investigated contamination by these 2 protozoa using multiplex quantitative real-time PCR. Among 404 vegetables, Cryptosporidium and Cyclospora were detected in 31 (7.7%) and 5 (1.2%) samples, respectively. In addition, Cryptosporidium was isolated from all 6 kinds of vegetables, whereas Cyclospora was detected in 4 kinds of vegetables (except perilla leaves and chives). Cryptosporidium (17.8%) and Cyclospora (2.9%) had the highest detection rates in chives and winter-grown cabbages, respectively. Cryptosporidium was detected all year long; however, Cyclospora was detected only from October to January. In 2 samples (sprout and blueberry), both Cryptosporidium and Cyclospora were detected. Further investigations using TaqI restriction enzyme fragmentation and nested PCR confirmed Cryptosporidium parvum and Cyclospora cayetanensis, respectively. In conclusion, we detected C. cayetanensis in vegetables for the first time in Korea. This suggests that screening should be employed to prevent these protozoal infections in Korea.

ESTIMATION OF THE CUMULATIVE EXPOSURE FREQUENCY AND CUMULATIVE EFFECTIVE DOSE OF DIAGNOSTIC MEDICAL RADIATION IN THE KOREAN POPULATION FROM 2002 TO 2010.

Along with increase in the frequency and exposure dose from the diagnostic medical radiation procedures, the public's interest in radiation exposure has also been growing. In this study, in order to estimate the Cumulative Exposure Frequency and the cumulative effective dose of diagnostic medical radiation in the Korean population, we included 680 diagnostic medical radiation procedure codes of the Health Insurance Review & Assessment Service's health insurance medical expenses data and adopted the effective dose data from the 2008 report of the United Nations Scientific Committee on the Effects of Atomic Radiation. We combined the data of one million individuals in the national sample cohort database (2002-10) of the National Health Insurance Service. The results revealed that 93.2% (917 972) of the subjects were exposed to diagnostic medical radiation at least once in the past nine years, and the Cumulative Exposure Frequency was 17 286.4 per 1000 individuals with a cumulative effective dose of 5.7 (±17.8) mSv per person. Additionally, 93.1% (854 480) of the subjects had a cumulative effective dose less than 20 mSv, and 0.7% (6139) had a dose that exceeded 100 mSv (extreme), showing that the dosage level was mostly low. However, the number of individuals whose exposure exceeded 100 mSv/y increased 28-fold, from 18 in 2002 to 500 in 2010. In addition, the size of increase also grew each year, suggesting that cancer occurrence due to diagnostic medical radiation may have also increased. In order determine the causal relationship between cancer occurrence and diagnostic medical radiation and setup a guideline for exposure, it is necessary to monitor individual cumulative exposure doses nation-wide and follow up on heavily exposed individuals for an extended period of time.

Rosiglitazone enhances radiosensitivity by inhibiting repair of DNA damage in cervical cancer cells.

Radiation therapy (RT) is one of the main treatment modalities for cervical cancer. Rosiglitazone (ROSI) has been reported to have antiproliferative effects against various types of cancer cells and also to induce antioxidant enzymes that can scavenge reactive oxygen species (ROS) and thereby modify radiosensitivity. Here, we explored the effect of ROSI on radiosensitivity and the underlying mechanisms in cervical cancer cells. Three cervical cancer cell lines (ME-180, HeLa, and SiHa) were used. The cells were pretreated with ROSI and then irradiated. Expression of proteins of interest was detected by western blot and immunofluorescence. Intracellular production of ROS was measured by H2DCFDA. Radiosensitivity was assessed by monitoring clonogenic survival. Expression of antioxidant enzymes (catalase, superoxide dismutases) was increased by ROSI in HeLa and SiHa cells, but not in ME-180 cells. With ROSI pre-treatment, cell survival after irradiation remained unchanged in HeLa and SiHa cells, but decreased in ME-180 cells. Radiation-induced expression of γ-H2AX was increased and that of RAD51 was decreased by ROSI pre-treatment in ME-180 cells, but not in HeLa cells. ROSI increases radiosensitivity by inhibiting RAD51-mediated repair of DNA damage in some cervical cancer cell lines; therefore, ROSI is a potential inhibitor of RAD51 that can be used to enhance the effect of RT in the treatment of some cervical cancers.

Silencing of fused toes homolog enhances cisplatin sensitivity in cervical cancer cells by inhibiting epidermal growth factor receptor-mediated repair of DNA damage.

PURPOSE: Overexpression of epidermal growth factor receptor (EGFR) is related to chemo-/radioresistance and poor prognosis in many cancers. EGFR is activated by cisplatin, and this may lead to resistance to this drug. Fused toes homolog (FTS) is an E2 variant that lacks the active cysteine residue required for ubiquitin transfer. Previously, we reported that FTS interacts with EGFR and activates DNA-dependent protein kinase (DNA-PK) upon irradiation. Here, we investigated the role of FTS in cisplatin sensitivity in ME180 cervical cancer cells. METHODS: Protein expression was assessed using western blot analyses in four cervical cell lines (ME180, CaSki, HeLa, and SiHa). FTS was silenced using a siRNA-based approach. Interactions between proteins were assessed by immunoprecipitation. Immunofluorescence was used to visualize DNA double-strand breaks and the expression of phospho-DNA-PK. RESULTS: Among the lines tested, ME180 cells showed the highest basal expression of EGFR and increased nuclear phosphorylated EGFR in response to cisplatin. In ME180 cells, the activation of EGFR and DNA-PK by cisplatin was attenuated by silencing FTS. FTS-silencing augmented cisplatin-induced cell death and cisplatin-induced DNA damage assessed by γH2AX. Immunoprecipitation showed binding of FTS with EGFR and DNA-PK. CONCLUSION: FTS is involved in EGFR-mediated repair of DNA damage induced by cisplatin in ME180 cells. This suggests that FTS can be a target to increase the efficacy of cisplatin in cervical cancer cells that exhibit increased nuclear phosphorylated EGFR in response to cisplatin.

T0070907 inhibits repair of radiation-induced DNA damage by targeting RAD51.

T0070907 (T007), a PPARγ inhibitor, can reduce α and ß tubulin proteins in some cancer cell lines. Thus, T007 has been suggested as an antimicrotubule drug. We previously reported that T007 increased radiosensitivity by inducing mitotic catastrophe in cervical cancer cells. In this study, we investigated the underlying mechanisms of the T007-mediated increase in radiosensitivity. T007 pre-treatment attenuated RAD51 protein levels and ionising radiation (IR)-induced nuclear foci formation, resulting in more frequent centrosome amplification and multipolar mitotic spindle formation in cervical cancer cells. Furthermore, T007 pre-treatment delayed the clearance of IR-induced γ-H2AX and increased radiosensitivity in cervical cancer cells. In contrast, none of these changes were observed in normal cells. Our data demonstrate for the first time that T007 impairs the repair of IR-induced DNA double-strand breaks by inhibiting RAD51, a key protein in homologous recombination repair, increases IR-induced mitotic catastrophe, and leads to increased death of IR-treated cells. These findings support T007 as a potential RAD51 inhibitor to increase tumour response to radiation therapy.