Knockdown of miR-15b partially reverses the cisplatin resistance of NSCLC through the GSK-3ß/MCL-1 pathway.

BACKGROUND: Induction of acquired drug resistance occurs frequently with cisplatin-based therapy for non-small cell lung cancer (NSCLC). As recent studies have demonstrated that deregulation of microRNAs (miRNAs) is associated with drug resistance in cancers, correcting the deregulation of miRNAs represents a promising strategy to reverse acquired resistance in NSCLC. OBJECTIVES: This study investigated the functional role of miR-15b in cisplatin resistance in NSCLC. MATERIAL AND METHODS: Cisplatin-resistant PC9 and A549 NSCLC cell lines (PC9-R and A549-R) were established through long-term exposure to cisplatin. Differences in miR-15b expression between cisplatin-resistant NSCLC cell lines and their parental cell lines were identified through quantitative real-time polymerase chain reaction (qRT-PCR). The effect of anti-miR-15b on the sensitivity of PC9-R and A549-R to cisplatin-induced cytotoxicity was evaluated using Cell Counting Kit-8 (CCK-8) assays. Regulation of GSK-3ß by miR-15b was confirmed with luciferase reporter assays. Cell apoptosis and mitochondrial membrane potential (MMP) were measured using flow cytometry analysis. RESULTS: In PC9-R and A549-R cells, miR-15b was significantly overexpressed. However, knockdown of miR-15b clearly reduced cisplatin resistance in PC9-R and A549-R cells. Researching the mechanism, we proved that GSK-3ß was the target of miR-15b. Knockdown of miR-15b significantly increased the expression GSK-3ß and thus promoted the degradation of MCL-1, which is a key anti-apoptosis protein. As a result, anti-miR-15b expanded the cisplatin-induced apoptosis in cisplatin-resistant NSCLC cells. CONCLUSIONS: Knockdown of miR-15b partially reversed cisplatin resistance in NSCLC cells through the GSK-3ß/MCL-1 pathway.

Is flexible bronchoscopy necessary in the preoperative workup of patients with peripheral cT1N0 subsolid lung cancer? -a prospective multi-center cohort study.

BACKGROUND: Necessity of flexible bronchoscopy (FB) examination as a routine preoperative work-up for peripheral clinical T1N0 subsolid lung cancer was unknown. METHODS: This was a prospective, multi-center clinical trial (NCT03591445). Patients with peripheral GGO nodules (GGNs) who were candidates for surgical resection were enrolled. FB examination was performed preoperatively. Surgical plan could be changed if any aberrant histologic and anatomic findings were detected by FB examination. Primary endpoint was the rate that surgical plan was changed by positive FB findings. Secondary endpoints were rate of positive FB findings and rate of procedural complications. RESULTS: Six hundred and fifteen patients with peripheral subsolid nodules detected by thoracic CT were enrolled. There were 187 (30.4%) male and 428 (69.6%) female patients, mean age was 54.85±10.41 y (range, 26-78). 262 (42.6%) patients had pure GGNs and 353 (57.4%) patients had part-solid nodules. Mean size of nodules was 13.87±6.37 mm (range, 5-30). FB examinations confirmed one (0.16%) adenocarcinoma, seven (1.14%) bronchial variations, one (0.16%) segmental bronchostenosis, one (0.16%) segmental bronchial occlusion and one (0.16%) bronchial inflammation. No complications of FB examinations occurred. 568 (92.35%) thoracoscopic and 47 (7.65%) open surgeries were performed. No established surgical plan was changed by positive FB findings. Final pathologies revealed 26 (4.2%) adenocarcinoma in situ (AIS), 240 (39%) minimal invasive adenocarcinomas (MIAs), 343 (55.8%) invasive adenocarcinomas (IADs), one (0.2%) adenosquamous cell carcinoma, one (0.2%) squamous cell carcinoma, two (0.3%) atypical adenoid hyperplasia and two (0.3%) inflammations. CONCLUSIONS: FB examination was unnecessary in the preoperative assessment of peripheral clinical T1N0 subsolid lung cancer.

Is 99m Tc bone scintigraphy necessary in the preoperative workup for patients with cT1N0 subsolid lung cancer? A prospective multicenter cohort study.

BACKGROUND: 99m Tc bone scintigraphy (BS) is still the most common approach for the evaluation of bone metastasis in China. The purpose of this study was to investigate the necessity of BS as part of a routine preoperative workup for patients with cT1N0 subsolid lung cancer. METHODS: This was a prospective multicenter clinical trial (NCT03689439). Patients with cT1N0 subsolid nodules who were candidates for surgical resection were consecutively enrolled into the study. BS was performed preoperatively. The surgical plan could be changed if a positive result was detected. The primary endpoint was the incidence rate of the surgical plan being changed because of positive BS results. The secondary endpoint was the rate of positive BS findings and the rate of related complications. RESULTS: From November 2018 to July 2019, 691 patients were enrolled into the study. None of the patients had positive BS results and no surgical plans were changed by BS findings. There were 222 male and 469 female patients. The average age was 54.8 ± 3.7 years old. The average tumor diameter was 14.9 ± 4.2 mm. There were 282 patients with pure GGO nodules and 409 with part-solid nodules. A total of 470 patients had a single nodule, while 221 patients had multifocal lesions. The number of patients whose pathological diagnosis was invasive adenocarcinoma, minimally invasive adenocarcinoma, adenocarcinoma in situ and mucinous adenocarcinoma was 357, 293, 32 and nine, respectively. The number of patients who underwent lobectomy, segmentectomy and wedge resection was 234, 199 and 258, respectively. CONCLUSIONS: 99m Tc bone scintigraphy is unnecessary in the preoperative workup for patients with cT1N0 subsolid lung cancer. KEY POINTS: SIGNIFICANT FINDINGS OF THE STUDY: In this prospective study of 691 patients with cT1N0 subsolid lung cancer, no surgical plans were affected by positive bone scan findings. WHAT THIS STUDY ADDS: We suggest physicians consider canceling BS from preoperative workup for cT1 subsolid lung cancer patients. Clinical trial registry number: NCT03689439.

lncRNA PCAT19 negatively regulates p53 in non-small cell lung cancer.

The present study aimed to investigate the influence of long non-coding (lnc)RNA prostate cancer associated transcript (PCAT)19 on the progression of non-small cell lung cancer (NSCLC). It was determined that PCAT19 expression was upregulated in NSCLC tissues and also predicted poor patient survival rate. Additionally, p53 expression was downregulated in NSCLC specimens, which was negatively correlated with PCAT19 expression. Moreover, in H1993 NSCLC cells, silencing of the PCAT19 gene led to an increase in the expression of p53, whilst conversely, its overexpression led to p53 downregulation. PCAT19 silencing was associated with the decreased proliferation rate of NSCLC cells, while PCAT19 overexpression led to increased proliferation. In addition, p53 overexpression, achieved through the transfection of a p53 expression vector, attenuated the effects of PCAT19 overexpression on cell proliferation. In conclusion, the present study demonstrated that PCAT19 negatively regulates the p53 tumor-suppression pathway, promoting cancer cell proliferation in patients with NSCLC.

MicroRNA-374a Inhibits Aggressive Tumor Biological Behavior in Bladder Carcinoma by Suppressing Wnt/ß-Catenin Signaling.

BACKGROUND/AIMS: microRNA (miR)-374a plays a crucial role in cancer progression by promoting the metastasis and proliferation of various types of malignant tumors. Because its role in bladder cancer is unknown, we investigated whether miR-374a affects the progression of bladder cancer and studied the underlying mechanism. METHODS: The Cancer Genome Atlas was used to analyze the clinical relevance of miR-374a. Quantitative PCR, western blotting, and luciferase and immunofluorescence assays were used to detect the expression patterns, downstream targets, and function of miR-374a in bladder cancer cells. Apoptosis was evaluated by flow cytometry after cisplatin treatment. RESULTS: Via in silico analysis, low levels of miR-374a were associated with poor prognosis in bladder cancer patients with distant metastasis. WNT5A was a direct target of miR-374a in two bladder cancer cell lines. miR-374a mimic abrogated the metastatic potential and invasiveness of bladder cancer cells via WNT5A downregulation in both T24 and TCCSUP human bladder cancer cells; the opposite was observed with miR-374a inhibitor. In addition, miR-374a treatment reduced the phosphorylation and nuclear translocation of ß-catenin. Cisplatin treatment significantly increased the apoptosis rate. Expression levels of cancer stemness-related proteins were reduced in miR-374a mimic-pretreated cells. CONCLUSION: Lower expression of miR-374a is associated with poor prognosis and miR-374a improves tumor biological behavior in bladder cancer cells, suggesting that miR-374a might be a novel small-molecule therapeutic target.

Clinicopathological features and prognosis of patients <45 years old with esophageal adenocarcinoma comparing to other age groups.

BACKGROUND: To analyze the clinicopathological features and prognosis of younger patients with esophageal adenocarcinoma (EAC). METHODS: A total of 2,601 patients diagnosed with EAC between 1988 and 2011 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. All patients underwent primary tumor resection and regional lymphadenectomy without preoperative radiotherapy. The patients were into four age groups (<45, 45-59, 60-74, ≥75), with 94, 813, 1,272 and 422 patients in each group respectively. RESULTS: Patients in the age <45 group were more likely to have lymph node (LN) metastasis (P=0.002), postoperative radiotherapy (P<0.001) and advanced T and N stage (P=0.003, 0.014) compared to the other three groups. We then conducted two Cox proportional hazards model adjusted for the sex, race, number of LNs examined, histological grade, postoperative radiation. The hazard ratio (HR) was higher in patients <45 y and the survival rate were paradoxically lower compared to the patients between 45-60 years old (P=0.046, 0.039). CONCLUSIONS: The patients <45 y had the most aggressive clinicopathological features of EAC and poorer survival rate after radical esophagectomy.