T790M mutation sensitizes non-small cell lung cancer cells to radiation via suppressing SPOCK1.

Background: Approximately 50% of patients harbor the T790M mutation after developing first-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) resistance. Evidence has showed the major treatment failure is local relapses and limited metastases. Several studies have demonstrated the value of radiotherapy in metastatic non-small cell lung cancer (NSCLC) with the EGFR T790M mutation after the development of TKI resistance. The aim of this study was to explore the role of radiation in T790M-mutant NSCLC and the value of early radiotherapy for NSCLC with T790M-mediated EGFR-TKI resistance. Methods: Gefitinib-resistant NSCLC cell lines were established via stepwise exposure to increasing concentrations of gefitinib (PC-9-GR). Droplet digital PCR was used to determine the relative T790M subclone abundance. In vitro and in vivo models were established using different mixtures of PC-9-GR and PC-9 cells. Differentially expressed genes were identified using RNA sequencing. Two research models were constructed (salvage and prophylactic radiotherapy) to determine the effects of early radiotherapy on gefitinib-resistant cells. Results: PC-9-GR cells exhibited higher radiosensitivity than PC-9 cells (sensitivity enhancement ratio = 1.5). Salvage radiation reduced the number of T790M-mutant subclones, and the relative T790M abundance was significantly lower than that without radiation at 90 days (10.94% vs. 21.54%). Prophylactic radiation prevented the development of T790M subclones. These results were also confirmed in vivo. qRT-PCR revealed threefold elevation of miR-1243 in PC-9-GR cells, and the increased radiosensitivity of PC-9-GR cells was inhibited when miR-1243 was knocked down. RNA sequencing revealed that SPOCK1 was downregulated in PC-9-GR cells. Interestingly, bioinformatic analysis showed that SPOCK1 was a target gene of miR-1243. SPOCK1 knockdown markedly increased the radiosensitivity of PC-9 cells. Conclusion: Gefitinib-resistant NSCLC with the T790M mutation had higher radiosensitivity than that without the mutation, possibly mediated by SPOCK1. Early radiotherapy can eliminate T790M subclones, providing evidence for the benefit of early local treatment in patients with TKI-resistant NSCLC.

Remarkable response to alectinib for metastatic papillary thyroid cancer with STRN-ALK fusion: A case report.

Little is known about the efficacy of alectinib for papillary thyroid cancer with STRN-ALK fusion. A 64-year-old female presented with metastatic papillary thyroid cancer, widespread to lungs, mediastinal lymph nodes and brain 20 years after surgery. Disease progression still occurred after radioactive iodine therapy, chemotherapy, and radiotherapy. Tissue obtained from left cervical lymph node confirmed metastatic papillary thyroid cancer. Molecular profiling from re-biopsy tissue identified an STRN-ALK fusion rearrangement. After multidisciplinary discussion, alectinib was administered to the patient. Treatment was well tolerated, and follow-up images confirmed a partial response. ALK occurs rarely, with limited data suggesting the efficacy of ALK inhibitors in thyroid cancer. We presented the first case of a patient with PTC and STRN-ALK fusion to be treat effectively with alectinib.

Positive Correlation of Peripheral CD8+ T Lymphocytes with Immune-Related Adverse Events and Combinational Prognostic Value in Advanced Non-Small Cell Lung Cancer Patients Receiving Immune Checkpoint Inhibitors.

Immune checkpoint inhibitors (ICIs) therapy has revolutionized the treatment patterns of non-small cell lung cancer (NSCLC). However, patients treated with ICIs may experience immune-related adverse events (irAEs). Markers that could predict the onset of irAEs are still unclear. Here, we report the possible correlation of baseline peripheral lymphocytes with irAEs and clinical outcomes in advanced NSCLC patients receiving ICIs. A total of 109 advanced NSCLC patients treated with ICIs from April 2017 to January 2021 were analyzed retrospectively. Logistic and Cox regression analyses was applied to evaluate independent risk factors for irAEs, progression-free survival (PFS), and overall survival (OS). Among these patients, 55 (50.5%) patients experienced irAEs. The level of CD8+ T lymphocytes at baseline was the independent risk factor for the onset of irAEs (p = 0.008). A higher level of CD8+ T lymphocytes was associated with longer PFS (11.0 months vs. 3.0 months, p < 0.001) and OS (27.9 months vs. 11.7 months, p = 0.014). Furthermore, patients who had higher baseline CD8+ T lymphocytes and experienced irAEs had a longer PFS (18.4 months vs. 2.2 months, p < 0.001) and OS (32.8 months vs. 9.0 months, p = 0.001) than those who had lower CD8+ T lymphocytes and no irAEs. Our study highlights the value of baseline peripheral CD8+ T lymphocytes as a predictive factor for irAEs in advanced NSCLC patients receiving ICIs. In addition, patients who have higher baseline CD8+ T lymphocytes and experience irAEs would have a superior PFS and OS.

Postoperative radiotherapy for patients with completely resected stage IIIA-N2 non-small cell lung cancer: opt-in or opt-out.

The role of adjuvant radiotherapy in completely resected pIIIA-N2 non-small cell lung cancer (NSCLC) has long been debated. Evidence from previous retrospective and prospective studies showed that postoperative radiotherapy could reduce the incidence of local recurrence and prolong disease-free survival, while two recently reported randomized controlled trials (lung ART and PORT-C) both demonstrated no survival benefit of postoperative radiotherapy. The great gap between our knowledge and reality has made us rethink the value of postoperative radiotherapy. In this mini review, we elaborate on the role of postoperative radiotherapy in completely resected pIIIA-N2 NSCLC.

SERPINE2/PN-1 regulates the DNA damage response and radioresistance by activating ATM in lung cancer.

Although the DNA damage response (DDR) is associated with the radioresistance characteristics of lung cancer cells, the specific regulators and underlying mechanisms of the DDR are unclear. Here, we identified the serine proteinase inhibitor clade E member 2 (SERPINE2) as a modulator of radiosensitivity and the DDR in lung cancer. Cells exhibiting radioresistance after ionizing radiation show upregulation of SERPINE2, and SERPINE2 knockdown improves tumor radiosensitivity in vitro and in vivo. Functionally, SERPINE2 deficiency causes a reduction in homologous recombination repair, rapid recovery of cell cycle checkpoints, and suppression of migration and invasion. Mechanistically, SERPINE2 knockdown inhibits the accumulation of p-ATM and the downstream repair protein RAD51 during DNA repair, and RAD51 can restore DNA damage and radioresistance phenotypes in lung cancer cells. Furthermore, SERPINE2 can directly interact with MRE11 and ATM to facilitate its phosphorylation in HR-mediated DSB repair. In addition, high SERPINE2 expression correlates with dismal prognosis in lung adenocarcinoma patients, and a high serum SERPINE2 concentration predicts a poor response to radiotherapy in non-small cell lung cancer patients. In summary, these findings indicate a novel regulatory mechanism by which SERPINE2 modulates the DDR and radioresistance in lung cancer.

Decitabine Sensitizes the Radioresistant Lung Adenocarcinoma to Pemetrexed Through Upregulation of Folate Receptor Alpha.

Chemotherapy is the backbone of subsequent treatment for patients with lung adenocarcinoma (LUAD) exhibiting radiation resistance, and pemetrexed plays a critical role in this chemotherapy. However, few studies have assessed changes in the sensitivity of LUAD cells to pemetrexed under radioresistant circumstances. Therefore, the objectives of this study were to delineate changes in the sensitivity of radioresistant LUAD cells to pemetrexed and to elucidate the related mechanisms and then develop an optimal strategy to improve the cytotoxicity of pemetrexed in radioresistant LUAD cells. Our study showed a much lower efficacy of pemetrexed in radioresistant cells than in parental cells, and the mechanism of action was the significant downregulation of folate receptor alpha (FRα) by long-term fractionated radiotherapy, which resulted in less cellular pemetrexed accumulation. Interestingly, decitabine effectively reversed the decrease in FRα expression in radioresistant cells through an indirect regulatory approach. Thereafter, we designed a combination therapy of pemetrexed and decitabine and showed that the activation of FRα by decitabine sensitizes radioresistant LUAD cells to pemetrexed both in vitro and in xenografts. Our findings raised a question regarding the administration of pemetrexed to patients with LUAD exhibiting acquired radioresistance and accordingly suggested that a combination of pemetrexed and decitabine would be a promising treatment strategy.

Thoracic radiotherapy and concurrent almonertinib for unresectable stage III EGFR-mutated non-small-cell lung cancer: a phase 2 study.

BACKGROUND: Concurrent chemo-radiotherapy remains the standard treatment in unresectable stage III non-small-cell lung cancer (NSCLC) patients. Several studies have shown a potential value of concurrent epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) with thoracic radiotherapy in EGFR-mutated population, but a high risk of radiation pneumonitis raised a major concern. This study intends to explore the safety and efficacy of concurrent almonertinib, a new third-generation EGFR-TKI, with radiotherapy in locally advanced EGFR-mutated NSCLC patients. METHODS: Locally advanced NSCLC patients harboring sensitive EGFR mutation will be included in this study. A radiotherapy plan will be made for each patient before treatment, and the lung V20 will be calculated. Patients with lung V20 ≥ 28% were enrolled in induction group (arm A), which almonertinib was given for 2 months followed by concurrent radiotherapy; patients with lung V20 < 28% were enrolled in concurrent group (arm B), which almonertinib was given concurrent with thoracic radiotherapy. The primary endpoint is the incidence of grade ≥ 3 radiation pneumonitis within 6 months post-radiotherapy, and the secondary endpoints are local control rate, progression-free survival, and overall survival. DISCUSSION: The safety and efficacy of third-generation EGFR-TKI concurrent with thoracic radiotherapy in locally advanced EGFR-mutated NSCLC is still unknown. We propose to conduct this phase 2 study evaluating the safety especially the radiation pneumonitis within 6 months post-radiotherapy. This trial protocol has been approved by the Ethics committee of Hangzhou cancer hospital. The ethics number is HZCH-2020-030. TRIAL REGISTRATION: clinicaltrials.gov, NCT04636593 . Registered 19 November 2020 - Retrospectively registered.

Cancer-associated fibroblasts in non-small cell lung cancer: Recent advances and future perspectives.

Non-small cell lung cancer (NSCLC) constitutes the majority of lung cancer, which is the leading cause of cancer-related deaths in the world. Nearly 70% of NSCLC patients were diagnosed at advanced stage with only 15% of five-year survival rate. Cancer-associated fibroblasts (CAFs) are the major component of tumor microenvironment and account for almost 70% of the cells in tumor tissues. By the crosstalk with cancer cells, CAFs reprogrammed cancer cell metabolism, remodeled extracellular matrix (ECM) and created a supportive niche for cancer stem cells. CAFs lead collective invasion of tumor cells and shape tumor immune microenvironment, promoting tumor metastasis and immune escape. In this review, we have summarized the progress of studies regarding CAFs influences on NSCLC in recent five years from the aspects of cell growth, metabolism, therapy resistance, invasion and metastasis and immune suppression. We have discussed the involved mechanisms and implications for the development of anti-NSCLC therapies. The current strategies of CAFs targeting and elimination have also been generalized. Only better understanding of the molecular biology of CAFs may contribute to the development of novel anti-NSCLC strategies.

Deep learning-based automatic delineation of the hippocampus by MRI: geometric and dosimetric evaluation.

BACKGROUND: Whole brain radiotherapy (WBRT) can impair patients' cognitive function. Hippocampal avoidance during WBRT can potentially prevent this side effect. However, manually delineating the target area is time-consuming and difficult. Here, we proposed a credible approach of automatic hippocampal delineation based on convolutional neural networks. METHODS: Referring to the hippocampus contouring atlas proposed by RTOG 0933, we manually delineated (MD) the hippocampus on the MRI data sets (3-dimensional T1-weighted with slice thickness of 1 mm, n = 175), which were used to construct a three-dimensional convolutional neural network aiming for the hippocampus automatic delineation (AD). The performance of this AD tool was tested on three cohorts: (a) 3D T1 MRI with 1-mm slice thickness (n = 30); (b) non-3D T1-weighted MRI with 3-mm slice thickness (n = 19); (c) non-3D T1-weighted MRI with 1-mm slice thickness (n = 11). All MRIs confirmed with normal hippocampus has not been violated by any disease. Virtual radiation plans were created for AD and MD hippocampi in cohort c to evaluate the clinical feasibility of the artificial intelligence approach. Statistical analyses were performed using SPSS version 23. P < 0.05 was considered significant. RESULTS: The Dice similarity coefficient (DSC) and Average Hausdorff Distance (AVD) between the AD and MD hippocampi are 0.86 ± 0.028 and 0.18 ± 0.050 cm in cohort a, 0.76 ± 0.035 and 0.31 ± 0.064 cm in cohort b, 0.80 ± 0.015 and 0.24 ± 0.021 cm in cohort c, respectively. The DSC and AVD in cohort a were better than those in cohorts b and c (P < 0.01). There is no significant difference between the radiotherapy plans generated using the AD and MD hippocampi. CONCLUSION: The AD of the hippocampus based on a deep learning algorithm showed satisfying results, which could have a positive impact on improving delineation accuracy and reducing work load.

Prophylactic chemotherapeutic hyperthermic intraperitoneal perfusion reduces peritoneal metastasis in gastric cancer: a retrospective clinical study.

BACKGROUND: Peritoneal metastasis is the most frequent failure in gastric cancer. This study evaluated the role of prophylactic chemotherapeutic hyperthermic intraperitoneal perfusion (CHIP) in patients after D2 dissection. METHODS: Gastric cancer patients after D2 dissection were enrolled in this study. Patients received either chemotherapy (IV group) or CHIP (CHIP group). Sites of recurrence or metastasis, disease-free survival (DFS), overall survival (OS) and adverse events were evaluated. RESULTS: Twenty-two patients received CHIP treatment, and 21 patients received chemotherapy alone. The median DFS time was 24.5 and 36.5 months in the IV group and CHIP group (P = 0.044), respectively. The median OS time was 33.1 months in the IV group and not reached in the CHIP group (P = 0.037). We also found that CHIP could reduce the total recurrence/metastasis rate, especially that of peritoneal metastasis. In the subgroup analysis, DFS and OS were both superior in deficient mismatch repair (dMMR) patients than in proficient MMR (pMMR) patients. CONCLUSION: This hypothesis-generating study indicates that CHIP might be feasible for gastric cancer patients after D2 resection.

Identification of somatic copy number variations in plasma cell free DNA correlating with intrinsic resistances to EGFR targeted therapy in T790M negative non-small cell lung cancer.

BACKGROUND: About 20-30% EGFR-mutant non-small lung cancer show intrinsic resistance to EGFR targeted therapies. Compared to T790M positive in acquired resistance patients, little is known about EGFR-TKI intrinsic resistance for T790M negative patients. METHODS: Thirty-one patients with advanced stage lung cancer, including 18 patients with intrinsic resistance (PFS <6 months) and 13 patients with acquired resistance (PFS >36 months) but are negative for plasma T790M were recruited in the study. Plasma cell free DNA was profiled by low coverage whole genome sequencing with median genome coverage of 1.86X by Illumina X10. Sequencing coverage across chromosomes was summarized by samtools, and normalized by segmentation analysis as provided by R package 'DNACopy'. RESULTS: The most frequent chromosomal changes were found on chr7, chr1 and chr8. Among them, chr7p gains were found in 12 (66.7%) intrinsic resistance and 4 (30.7%) acquired resistance patients. The gene EGFR was found located on the focal amplification peak of chr7p. The performance of 7p gain to predict intrinsic resistance reaches AUC =0.902. Similarly, focal amplifications were also found on chromosome 5, 16 and 22, where tumor related gene PCDHA@, ADAMTS18 and CRKL were located. Focal deletions were also found in chr1, 8, 10 and 16, where genes SFTPA1/2, DLC1, PTEN and CDH1 are located. CONCLUSIONS: The results suggest cell free DNA copy number might be a useful peripheral blood tumor biomarker for predicting intrinsic resistance of EGFR targeted therapy and prognosis.

Regional Hyperthermia Combined with Chemotherapy in Advanced Gastric Cancer.

INTRODUCTION: This study aims to investigate the potential effects of regional hyperthermia combined with chemotherapy (RHCT) as a treatment strategy for advanced gastric cancer (AGC). METHOD: 118 AGC patients were randomly divided into treatment plans with chemotherapy (CT) alone or with RHCT. The prognostic value of clinicopathologic characteristics was assessed in terms of overall survival of AGC patients. RESULTS: The disease control rate was determined to be 70.9% and 46.0% for the RHCT and CT group, respectively (P = 0.006). The median survival was determined to be 23.5 months for the RHCT group and 14.0 months for the CT group (P = 0.010). The 3-year survival rate for the RHCT group was 11.4% and 0% for the CT group (P = 0.018). No difference in grade 3 or 4 adverse events was observed between the two groups (P > 0.05). Multivariate analysis showed that hyperthermia, disease stage, Glasgow prognostic score, and abdominal metastasis were closely associated with the prognosis of these AGC patients. CONCLUSION: The study suggests that combination treatment with RHCT for AGC has clinical potential for both short- and long-term curative effects without compromising toxicity.

Intraperitoneal perfusion chemotherapy and whole abdominal hyperthermia using external radiofrequency following radical D2 resection for treatment of advanced gastric cancer.

BACKGROUND: The peritoneum is the most frequent site of disease recurrence in gastric cancer, and the prognosis remains poor. This study assessed the role of adjuvant intraperitoneal (IP) chemotherapy with whole abdominal hyperthermia using external radiofrequency in gastric cancer patients after D2 dissection. METHODS: Patients with gastric cancer who underwent gastrectomy with D2 regional lymph node dissection were enrolled in the study. Patients received IP chemotherapy with whole abdominal hyperthermia. Preheated normal saline containing 75 mg/m2 of cisplatin was delivered into the abdominal cavity through a Tenckhoff catheter at McBurney's point. Regional hyperthermia was performed using two sets of orthogonal radiofrequency waves immediately after all saline was irrigated into the abdominal cavity. For each patient, recurrent or metastatic sites and adverse events were evaluated. RESULTS: A total of 22 patients were finally included. All patients tolerated hyperthermia well. Only two patients experienced grade 1 superficial thermal injury. The most frequent grade 3/4 adverse events were myelosuppression, nausea/vomiting, trichomadesis and liver dysfunction. We also found IP chemotherapy with whole abdominal hyperthermia could reduce the total recurrent/metastatic rate, especially peritoneal metastasis (4.5%). CONCLUSIONS: This hypothesis-generating study indicated that IP chemotherapy with whole abdominal hyperthermia might be feasible for gastric cancer patients after D2 resection.

A phase II study of concurrent nab-paclitaxel/carboplatin combined with thoracic radiotherapy in locally advanced squamous cell lung cancer.

BACKGROUND: The development of chemoradiotherapy is urgently needed for locally advanced squamous cell lung cancer due to its poor prognosis and significant toxicity. Carboplatin combined with nab-paclitaxel is a useful choice as first-line therapy in advanced squamous cell lung cancer. This prospective phase II study aimed to explore the efficacy and toxicity of concurrent chemoradiotherapy with nab-paclitaxel, carboplatin, and thoracic radiotherapy in unresectable locally advanced squamous cell lung cancer. METHODS: Patients with unresectable stage III squamous cell lung cancer were eligible. All patients received nab-paclitaxel weekly at a dose of 60 mg/m2, in combination with carboplatin [area under the plasma concentration time curve (AUC) 2] weekly during concurrent chemoradiotherapy. Thoracic radiation was administered at a dose of 66 Gy/33 fractions. The consolidation chemotherapy consisted of nab-paclitaxel (260 mg/m2 on day 1) and carboplatin (AUC 6 on day 1) every 21 days was administered in two cycles after the concurrent chemoradiotherapy. The primary endpoint was objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety. RESULTS: Initially, enrollment of 21 patients was planned; however, the trial was prematurely closed due to slow recruitment. Finally, a total of 8 patients were enrolled between January 2012 and July 2015 from one institute. All patients completed concurrent chemoradiotherapy, and 6 patients (75.0%) received consolidation chemoradiotherapy. The ORR was 75%, with complete response (CR) 1 (12.5%), partial remission 6 (62.5%), stable disease 1 (12.5%), progressive disease 1 (12.5%), respectively. After a median follow-up of 15.2 (range, 2.3-51.5) months, 7 patients were dead, and 1 was alive. The median PFS and OS were 12.1 and 15.2 months, respectively. According to Common Terminology Criteria for Adverse Events version 4.0, 6 patients (75.0%) experienced acute radiation esophagitis, 4 (50.0%) were grade 2 (G2), and 2 (25.0%) were G3; 4 patients (50%) experienced acute radiation pneumonitis, 3 (37.5%) were G2, and 1 (12.5%) was G3. No late radiation-induced esophageal and pulmonary toxicity was observed after 1-year follow-up. CONCLUSIONS: Concurrent nab-paclitaxel, carboplatin, and thoracic radiotherapy was shown to be an effective regimen for patients with unresectable locally advanced squamous cell lung cancer; however, further study should exercise caution due to the severe radiation esophagitis.

ctDNA assessment of EGFR mutation status in Chinese patients with advanced non-small cell lung cancer in real-world setting.

BACKGROUND: The prevalence of EGFR mutations in circulating free tumor-derived DNA (ctDNA) was still unknown in China. This large-scale study (NCT02623257) aimed to explore the prevalence of epidermal growth factor receptor (EGFR) mutations and determine the correlation of EGFR mutation status with clinical characteristics. METHODS: Plasma DNA samples from 1,001 patients with stage III/IV NSCLC who received ≤1st line chemotherapy were collected from 65 hospitals. EGFR mutations were tested by amplification refractory mutation system (ARMS) method. The EGFR mutation rate was calculated and the associations between EGFR status and patients' demographic data, disease status as well as treatment pattern were explored. RESULTS: EGFR mutations were detected in 251 of 1,001 (25.1%) patients, 26.8% in adenocarcinoma and 11.7% in squamous carcinoma. A total of 189 harbored sensitizing mutations alone, 28 had resistance mutations alone, 3 had a combination of activating mutations, and 31 had a combination of activating and resistance mutations. Higher detection rate was observed in chemotherapy-naïve patients than those received 1st line chemotherapy (27.0% vs. 18.0%; P=0.006). Of which, the mutation rate of exon 19 deletion was 9.31% for naïve patients and 7.37% for the 1st chemotherapy patients; while the mutation rate of L858R decreased obviously from 10.20% (naïve) to 3.69% (1st line). We also noticed the mutation rate was 37.1% in patients with ≥2 organ metastases. Multivariate analysis showed female, chemotherapy-naïve, or ≥2 metastatic organs patients had higher EGFR mutation rate. CONCLUSIONS: ctDNA based EGFR mutation test is feasible and could be a surrogate when tissue biopsy is not available.

Correction to: Comparison of the Amplification Refractory Mutation System, Super Amplification Refractory Mutation System, and Droplet Digital PCR for T790 M Mutation Detection in Non-small Cell Lung Cancer after Failure of Tyrosine Kinase Inhibitor Treatment.

The affiliation of first author (Lucheng Zhu) should be Department of Oncology, Hangzhou Cancer Hospital and Department of Oncology, Hangzhou First People's Hospital, Nanjing Medical University.

Microwave hyperthermia promotes caspase­3-dependent apoptosis and induces G2/M checkpoint arrest via the ATM pathway in non­small cell lung cancer cells.

Post-operative microwave (MW) hyperthermia has been applied as an important adjuvant therapy to enhance the efficacy of traditional cancer treatment. A better understanding of the molecular mechanisms of MW hyperthermia may provide guided and further information on clinical hyperthermia treatment. In this study, we examined the effects of MW hyperthermia on non­small cell lung carcinoma (NSCLC) cells in vitro, as well as the underlying mechanisms. In order to mimic clinical treatment, we developed special MW heating equipment for this study. Various NSCLC cells (H460, PC-9 and H1975) were exposed to hyperthermia treatment using a water bath or MW heating system. The results revealed that MW hyperthermia significantly inhibited cell growth compared with the water bath heating system. Furthermore, MW hyperthermia increased the production of reactive oxygen species (ROS), decreased the levels of mitochondrial membrane potential (MMP) and induced caspase­3 dependent apoptosis. It also induced G2/M phase arrest through the upregulation of the expression of phosphorylated (p­) ataxia telangiectasia mutated (ATM), p­checkpoint kinase 2 (Chk2) and p21, and the downregulation of the expression of cdc25c, cyclin B1 and cdc2. On the whole, the findings of this study indicate that the exposure of NSCLC cells to MW hyperthermia promotes caspase­3 dependent apoptosis and induces G2/M cell cycle arrest via the ATM pathway. This preclinical study may help to provide laboratory-based evidence for MW hyperthermia treatment in clinical practice.

Epidermal growth factor receptor (EGFR) T790M mutation identified in plasma indicates failure sites and predicts clinical prognosis in non-small cell lung cancer progression during first-generation tyrosine kinase inhibitor therapy: a prospective observational study.

INTRODUCTION: Plasma circulating tumor DNA (ctDNA) is an ideal approach to detecting the epidermal growth factor receptor (EGFR) T790M mutation, which is a major mechanism of resistance to first-generation EGFR-tyrosine kinase inhibitor (TKI) therapy. The present study aimed to explore the association of ctDNA-identified T790M mutation with disease failure sites and clinical prognosis in non-small cell lung cancer (NSCLC) patients. METHODS: Patients who progressed on first-generation TKIs were categorized into failure site groups of chest limited (CF), brain limited (BF) and other (OF). Amplification refractory mutation system (ARMS) and droplet digital PCR (ddPCR) were used to identify the T790M mutation in ctDNA. Prognosis was analyzed with Kaplan-Meier methods. RESULTS: Overall concordance between the two methods was 78.3%. According to both ARMS and ddPCR, patients in the OF group had a significantly higher rate of T790M mutation than did patients in the BF and CF groups (P < 0.001), and a significantly higher T790M mutation rate was also observed in OF-group patients than in those in the CF and BF groups (P < 0.001). AZD9291 was found to be an excellent treatment option and yielded the longest survival for T790M+ patients in all groups who had progressed on EGFR-TKIs; for other treatments, the prognosis of T790M- patient subgroups varied. CONCLUSIONS: The present study demonstrates that T790M mutation in ctDNA is associated with failure sites for NSCLC patients after EGFR-TKI therapy and indicates that both failure site and T790M mutational status greatly influence treatment selection and prognosis.

S-allylcysteine suppresses ovarian cancer cell proliferation by DNA methylation through DNMT1.

BACKGROUND: The anti-tumor effects of S-allylcysteine (SAC), a water-soluble garlic derivative, on human ovarian cancer cells have been previous studied in vitro and in vivo models but the precise epigenetic molecular mechanisms are still unclear. This study aimed to investigate the epigenetic mechanism of SAC. METHODS: Human epithelial ovarian cancer cell line A2780 was selected. Cell proliferation and cell cycle was analyzed. DNA methylation, DNA methyltransferase (DNMT) activity, tumor suppressor gene expressions, as well as protein expression were analyzed. RESULTS: SAC could inhibit the proliferation of A2780 cells in dose- and time-dependent manners (the IC50 was 16.25 mmol/L and 5.25 mmol/L at 48 h and 72 h). Treatment of A2780 cells with SAC resulted in G1/S phase arrest. SAC treatment decreased global DNA methylation levels in A2780 cells in a dose-dependent manner. SAC decreased the levels of 5-methylcytosine, DNMT activity, messenger RNA (mRNA) and protein levels of DNMT1. Additionally, SAC treatment resulted in re-expression of the mRNA and proteins of silenced tumor suppressor gene CDKN1A accompany with reduced cell division control 2 expression. CONCLUSION: Our data indicated the potential therapeutic effects of SAC on the human ovarian carcinoma cell line A2780 in vitro. The epigenetic mechanism of action of SAC may have important implications for epigenetic therapy.

AZD9291 Increases Sensitivity to Radiation in PC-9-IR Cells by Delaying DNA Damage Repair after Irradiation and Inducing Apoptosis.

AZD9291 is a novel, irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), which is administered orally. It has been proven effective in non-small cell lung cancer (NSCLC) patients, with both EGFR-sensitizing and EGFR T790M mutations in preclinical models. However, the potential therapeutic effects of AZD9291 combined with other modalities, including ionizing radiation, are not well understood. The presence of AZD9291 significantly increases the cell-killing effects of radiation in PC-9-IR cells with a secondary EGFR mutation (T790M), which was developed from NSCLC PC-9 cells (human lung adenocarcinoma cell with EGFR 19 exon 15 bp deletion) after chronic exposure to increasing doses of gefitinib, and in H1975 cells (human lung adenocarcinoma cell with EGFR exon 20 T790M mutation de novo), but not in PC-9 cells or in H460 cells (human lung adenocarcinoma cell with wild-type EGFR). In PC-9-IR cells, AZD9291 remarkably decreases phosphorylation levels of EGFR, extracellular regulated protein kinase (ERK), and protein kinase B (AKT). AZD9291 increases sensitivity to radiation in PC-9-IR cells by delaying deoxyribonucleic acid (DNA) damage repair after irradiation and inducing apoptosis, and enhances tumor growth inhibition when combined with radiation in PC-9-IR xenografts. Our findings suggest a potential therapeutic effect of AZD9291 as a radiation sensitizer in lung cancer cells with an acquired EGFR T790M mutation, providing a rationale for a clinical trial using the combination of AZD9291 and radiation in NSCLCs harboring acquired T790M mutation.