LKB1 Mutations Enhance Radiosensitivity in Non-Small Cell Lung Cancer Cells by Inducing G2/M Cell Cycle Phase Arrest.

BACKGROUND: Radiosensitivity remains an important factor affecting the clinical outcome of radiotherapy for non-small cell lung cancer (NSCLC). Liver kinase B1 (LKB1) as a tumor suppressor, is one of the most commonly mutated genes in NSCLC. However, the role of LKB1 on radiosensitivity and the possible mechanism have not been elucidated in the NSCLC. In this study, we investigated the regulatory function of LKB1 in the radiosensitivity of NSCLC cells and its possible signaling pathways. METHODS: After regulating the expression of LKB1, cell proliferation was determined by Cell Counting Kit-8 (CCK-8) assay. The flow cytometry assay was used to analyse cell cycle distribution. Survival fraction and sensitization enhancement ratio (SER) were generated by clonogenic survival assay. Western blot analysis was used to assess expression levels of LKB1, p53, p21, γ-H2AX and p-Chk2. RESULTS: Our study found that when the NSCLC cells were exposed to ionizing radiation, LKB1 could inhibit NSCLC cell proliferation by promoting DNA double strand break and inducing DNA repair. In addition, LKB1 could induce NSCLC cells G1 and G2/M phase arrest through up-regulating expression of p53 and p21 proteins. CONCLUSION: This current study demonstrates that LKB1 enhances the radiosensitivity of NSCLC cells via inhibiting NSCLC cell proliferation and inducing G2/M phase arrest, and the mechanism of cell cycle arrest associated with signaling pathways of p53 and p21 probably.

Toxicity, Disease Control, and Survival Outcomes of Intensified Preoperative Chemoradiotherapy in Patients with Locally Advanced Rectal Cancer: A Single-Institution Study.

Purpose: The standard treatment regimen of preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC) is still controversial. The purpose of this study was to analyze the efficacy and safety of preoperative intensive CRT in our institution. Methods: A retrospective data collection and analysis of 181 LARC patients receiving oxaliplatin (85%) of standard doses in capecitabine-based preoperative CRT and two additional cycle of neoadjuvant chemotherapy between the end of concurrent CRT and surgery. Results: The compliance of the preoperative CRT was satisfactory with 99.4%patients completed radiotherapy and 97.19%patients completed all 2 cycles of concurrent chemotherapy. Except for 20 patients diagnosed clinical complete remission (cCR) managed according to watch and wait strategy, 160 patients received R0 radical surgery. The pathological complete response (pCR) rate was 23.75% (38/160) and tumor regression grade (TRG) 0/1 was 40% (72/180). In terms of tumor downstaging, 89 (55.63%) had T downstaging while 115 (71.88%) had N downstaging. The 1-overall survival (OS),2-OS,3-OS and 5-OS were 98.7%, 96.5%, 91.4% and 81.5%, respectively. The total rate of sphincter preservation was 86.25% (138/160) and the rate of patients with low rectal cancer was 73.0% (54/74) without affecting local control rates and survival rates. Both acute adverse reactions to preoperative CRT and postoperative complications were tolerable and controllable. Conclusion: In this retrospective study, preoperative intensive CRT of patients with LARC achieved satisfied disease control and survival outcomes and well acquired the sphincter retention rate in recent years in our institution. On the basis of these findings, a Phase III study to definitively test the intensified preoperative CRT strategy is warranted.

The efficacy and adverse effects of anlotinib in the treatment of high-grade glioma: A retrospective analysis.

Introduction: Anlotinib, a novel multi-kinase inhibitor, was found to improve progression-free survival (PFS) in brain metastases. Methods: This paper retrospectively analyzed 26 newly diagnosed or recurrent high-grade gliomas from 2017 to 2022, and the patients received oral anlotinib during concurrent postoperative chemoradiotherapy or after recurrence. Efficacy was evaluated according to the Response Assessment in Neuro-Oncology (RANO) criteria, and the main study endpoints were PFS at 6 months and overall survival (OS) at 1 year. Results: After the follow-up, until May 2022, 13 patients survived and 13 patients died, with a median follow-up time of 25.6 months. The disease control rate (DCR) was 96.2% (25/26), and the overall response rate (ORR) rate was 73.1% (19/26). The median PFS after oral anlotinib was 8.9 months (0.8-15.1), and the PFS at 6 months was 72.5%. The median OS after oral anlotinib was 12 months (1.6-24.4), and the OS at 12 months was 42.6%. Anlotinib-related toxicities were observed in 11 patients, mostly grades 1-2. In the multivariate analysis, patients with Karnofsky Performance Scale (KPS) above 80 had a highermedian PFS of 9.9months (p = 0.02), and their sex, age, IDH mutation, MGMTmethylation, and whether anlotinib was combined with chemoradiotherapy or maintenance treatment had no effect on PFS. Conclusion: We found that anlotinib combined with chemoradiotherapy in treating high-grade central nervous system (CNS) tumors can prolong PFS and OS and that it was safe.

Study on Motion Management of Pancreatic Cancer Treated by CyberKnife.

PURPOSE: We investigated the movement characteristics of pancreas and the clinical accuracy of tracking pancreas with the Synchrony Respiratory Tracking System (SRTS) during the CyberKnife treatment. These data provide a clinical data basis for the expansion margins of pancreatic tumor target. METHODS AND MATERIALS: Forty-two patients with pancreatic cancer treated by CyberKnife were retrospectively studied. The pancreatic displacement calculated from the x-ray images collected during the time interval between two consecutive movements constituted a data set. RESULTS: The total mean motion amplitudes and standard deviations of pancreatic tumors in SI, LR, AP, and radial directions were 3.66 ± 1.71 mm, 0.97 ± 0.62 mm, 1.52 ± 1.02 mm, and 1.36 ± 0.49 mm, respectively. The overall mean correlation errors and standard deviations were 0.82 ± 0.46 mm, 0.47 ± 0.33 mm, 0.41 ± 0.24 mm, and 0.98 ± 0.37 mm, respectively. The overall mean prediction errors and standard deviations were 0.57 ± 0.14 mm, 0.62 ± 0.28 mm, 0.39 ± 0.17 mm, and 1.58 ± 0.36 mm, respectively. The correlation errors and prediction errors of pancreatic tumors at different anatomical positions in SI, LR, and AP directions were statistically significant (p < 0.05). CONCLUSIONS: The tumor motion amplitude, the tumor location, and the treatment time are the main factors affecting the tracking accuracy. The pancreatic tumors at different anatomical locations should be treated differently to ensure sufficient dose coverage of the pancreatic target area.

Efficacy and Prognostic Factors of Trans-Arterial Chemoembolization Combined With Stereotactic Body Radiation Therapy for BCLC Stage B Hepatocellular Carcinoma.

PURPOSE: This study aimed to evaluate the efficacy and safety of trans-arterial chemoembolization (TACE) followed by stereotactic body radiation therapy (SBRT) in treating Barcelona Clinic Liver Cancer (BCLC) stage B hepatocellular carcinoma (HCC) not amenable to resection and radiofrequency ablation (RFA). METHODS: From February 2012 to January 2017, a total of 57 BCLC stage B HCC patients who were unsuitable candidates for resection and RFA treated with TACE combined with CyberKnife SBRT were included in this retrospective study. Patients underwent TACE for a median of two times (1-5 times) before SBRT. SBRT prescription doses ranged from 30 Gy to 50 Gy in 3-5 fractions. RESULTS: The median follow-up time was 42 months. The objective response rate (CR + PR) was 85.9%, and the disease control rate (CR + PR + SD) was 96.5%. The local control (LC) rates were 91.1% and 84.3% at 1 and 2 years, respectively. The 1-, 2-, 3-year overall survival (OS) and the median survival time were 73.2%, 51.4%, 32.4% and 26.6 months, respectively. The 1-, 2-, and 3-year progression-free survival (PFS) were 34.2%, 21.6%, and 9%, respectively, with a median PFS time of 9.7 months. A subgroup analysis was conducted in 32 patients with AFP ≥ 200 ng/ml before TACE. OS was significantly prolonged in those with AFP that decreased by more than 75% than those with AFP that decreased by less than 75% (P = 0.018) after SBRT. The treatment was well tolerated with only one patient (1.8%) developed grade 3 gastrointestinal toxicity, and another patient developed non-classical RILD. In multivariate analysis, tumor length ≥ 10 cm and AFP ≥ 200 ng/ml were independent poor prognostic factors for OS. CONCLUSION: The combination of TACE and Cyberknife SBRT showed optimal efficacy with acceptable toxicity for BCLC stage B HCC.

Concurrent chemoradiotherapy with raltitrexed and nedaplatin regimen for esophageal squamous cell carcinoma.

BACKGROUND: The aim of the study reported here was to evaluate the feasibility and safety of raltitrexed and nedaplatin with concurrent radiotherapy in patients with unresectable, locally advanced esophageal squamous cell carcinoma (ESCC). METHODS: Eligible patients were adults with newly diagnosed untreated, unresectable esophageal cancer in stages I to IV with lymph node metastases or cervical esophageal cancer. Patients received nedaplatin 25 mg/m per day on day 1-3, raltitrexed 3 mg/m on days 1 repeated every 21 days for 2 cycles, and combined concurrent radiotherapy (2 Gy/fraction, total dose of 60 Gy). RESULT: Thirty patients were included with squamous cell carcinoma. The median follow-up duration was 24 months. The overall response rate was 90%. The 1-year and 2-year overall survival rates for all patients were 70.4% and 55.7% with a median survival time of 30 months, and the median progression free survival was 20 month. The major toxicities were leukopenia and thrombopenia, with grade 3 to 4 leukopenia and thrombopenia were 50% and 30% of patients. CONCLUSION: Concurrent chemoradiotherapy with raltitrexed and nedaplatin agents frequently caused myelosuppression but was highly active and suggested to be a promising treatment option for locally advanced ESCC.

Attenuated LKB1-SIK1 signaling promotes epithelial-mesenchymal transition and radioresistance of non-small cell lung cancer cells.

BACKGROUND: Radiotherapy is one of the main therapeutic approaches for non-small cell lung cancer (NSCLC). However, radioresistant cancer cells can eventually cause tumor relapse and even fatal metastasis. It is thought that radioresistance and metastasis could be potentially linked by epithelial-mesenchymal transition (EMT). In this study, we established radioresistant NSCLC cells to investigate the potential relationship among radioresistance, EMT, and enhanced metastatic potential and the underlying mechanism involving liver kinase B1 (LKB1)-Salt-inducible kinase 1 (SIK1) signaling. METHODS: The radioresistant cell lines A549R and H1299R were generated by dose-gradient irradiation of the parental A549 and H1299 cells. The radioresistance/sensitivity was evaluated by Cell Counting Kit-8 assay, apoptosis analysis, and/or clonogenic cell survival assay. The EMT phenotype and the signaling change were assessed by Western blotting. The abilities of invasion and migration were evaluated by transwell assays and wound healing assays. RESULTS: The radioresistant cell lines A549R and H1299R displayed mesenchymal features with enhanced invasion and migration. Mechanistically, A549R and H1299R cells had attenuated LKB1-SIK1 signaling, which leaded to the up-regulation of Zinc-finger E-box-binding homeobox factor 1 (ZEB1)--a transcription factor that drives EMT. Re-expression of LKB1 in A549R cells reversed the EMT phenotype, whereas knockdown of LKB1 in H1299R cells further promoted the EMT phenotype. Moreover, re-expression of LKB1 in A549 cells increased the radiosensitivity, whereas knockdown of LKB1 in H1299 cells decreased the radiosensitivity. CONCLUSIONS: Our findings suggest that attenuated LKB1-SIK1 signaling promotes EMT and radioresistance of NSCLC cells, which subsequently contributes to the enhanced metastatic potential. Targeting the LKB1-SIK1-ZEB1 pathway to suppress EMT might provide therapeutic benefits.