Pancreatic cancer (PC) is a highly lethal human cancer. We previously found that Serine protease 3 (PRSS3), as an oncogene, is significantly upregulated in PC. In this study, we aimed to investigate the potential mechanism of PRSS3 dysregulation in PC. In this research, low miR-217 and high circ-ADAM9 expression were found in PC tissues and cell lines, which was closely associated with advanced clinical stage and lymph node metastasis. Patients with low miR-217 or high circ-ADAM9 expression had shorter survival time than those with high miR-217 or low circ-ADAM9 expression. Functionally, manipulation of miR-217 and circ-ADAM9 expression showed opposite effects on cell proliferation, migration and invasion. Stepwise mechanism studies indicated that circ-ADAM9 alleviated the inhibitory effect of miR-217 on PRSS3 by directly sponging miR-217 to increase the expression level of PRSS3, resulting in the activation of ERK/VEGF signalling pathway. In vivo, circ-ADAM9 silencing or miR-217 overexpression evidently retarded the growth of tumour, and the combination of them exhibited an additive inhibitory effect on tumourigenicity. Briefly, the ceRNA regulatory network of circ-ADAM9/miR-217/PRSS3 plays a pivotal role in PC progression by the regulation of ERK/VEGF signalling pathway.

ROS1 gene rearrangements have been reported in diverse cancer types including non‐small‐cell lung cancer (NSCLC), and with a notably higher prevalence in lung adenocarcinoma. The tyrosine kinase inhibitors, crizotinib, lorlatinib, and entrectinib, have demonstrated favorable efficacy in treating ROS1‐rearranged NSCLCs. Herein, we retrospectively reviewed 17 158 NSCLC patients whose tumor specimen and/or circulating cell‐free DNA underwent comprehensive genomic profiling. A total of 258 unique patients were identified with ROS1 rearrangements, representing an overall prevalence of approximately 1.5% of ROS1 fusions in newly diagnosed and relapsed NSCLC patients. CD74 (38%) was the most common fusion partner of ROS1, followed by EZR (13%), SDC4 (13%), SLC34A2 (10%), and other recurrent fusion partners with lower frequencies, including TPM3, MYH9, and CCDC6. Variant breakpoints occurred in ROS1 introns 33 (37%), 31 (25%), 32 (17%), and 34 (11%) with no obvious hotspots. CD74 (63%) and EZR (50%) were more frequently fused to ROS1 intron 33 than other introns, while ROS1 intron 31 was most frequently fused with SDC4 (79%) and SLC34A2 (81%). Crizotinib progression‐free survival (PFS) was not significantly different between fusion variants involving breakpoints in different ROS1 introns, nor was there a significant difference in PFS between CD74‐ROS1 and non‐CD74‐ROS1 groups of patients. Furthermore, TP53 was most frequently mutated in patients who progressed on crizotinib, and TP53 mutations were significantly associated with shorter crizotinib PFS. ROS1 mutations, including G2032R, were observed in approximately 33% of post‐crizotinib samples. Collectively, we report the prevalence of ROS1 fusions in a large‐scale NSCLC population and the efficacy of crizotinib in treating patients with ROS1‐rearranged NSCLC.

Background: Complex kinase rearrangement, a mutational process involving one or two chromosomes with clustered rearrangement breakpoints, interferes with the accurate detection of kinase fusions by DNA-based next-generation sequencing (NGS). We investigated the characteristics of complex ALK rearrangements in non-small cell lung cancers using multiple molecular tests. Methods: Samples of non-small cell lung cancer patients were analyzed by targeted-capture DNA-based NGS with probes tilling the selected intronic regions of fusion partner genes, RNA-based NGS, RT-PCR, immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Results: In a large cohort of 6576 non-small cell lung cancer patients, 343 (5.2%) cases harboring ALK rearrangements were identified. Fourteen cases with complex ALK rearrangements were identified by DNA-based NGS and classified into three types by integrating various genomic features, including intergenic (n = 3), intragenic (n = 5) and “bridge joint” rearrangements (n = 6). All thirteen cases with sufficient samples actually expressed canonical EML4-ALK fusion transcripts confirmed by RNA-based NGS. Besides, positive ALK IHC was detected in 13 of 13 cases, and 9 of 11 cases were positive in FISH testing. Patients with complex ALK rearrangements who received ALK inhibitors treatment (n = 6), showed no difference in progression-free survival (PFS) compared with patients with canonical ALK fusions n = 36, P = 0.9291). Conclusions: This study firstly reveals the molecular characteristics and clinical outcomes of complex ALK rearrangements in NSCLC, sensitive to ALK inhibitors treatment, and highlights the importance of utilizing probes tilling the selected intronic regions of fusion partner genes in DNA-based NGS for accurate fusion detection. RNA and protein level assay may be critical in validating the function of complex ALK rearrangements in clinical practice for optimal treatment decision.

Background/Aims: This study aims to examine the effect of long noncoding RNA HOST2 (LncRNA HOST2) on epithelial-mesenchymal transition (EMT), proliferation, invasion and migration of hepatocellular carcinoma (HCC) cells via activation of the JAK2-STAT3 signaling pathway. Methods: HCC and para-cancerous tissues were collected from 136 HCC patients. Immunohistochemistry was used to detect the expression of JAK2 and STAT3. HCC SMMC7721 cells were grouped into blank, negative control (NC), HOST2 mimic and HOST2 inhibitor groups. The mRNA and protein expression levels of HOST2, JAK2, STAT3, E-cadherin, vimentin, Snail, Slug, Twist and Zeb1 in tissues and cells were determined by reverse transcription -quantitative polymerase chain reaction (RT-qPCR) and Western blotting, respectively. An MTT assay, scratch test and Transwell assay were applied to measure cell proliferation, migration and invasion, respectively. Results: The levels of JAK2, STAT3 and vimentin were higher in HCC tissues, while the expression of E-cadherin was lower in HCC tissues compared with para-cancerous tissues. The silencing of HOST2 significantly decreased cell proliferation, migration and invasion, reduced the levels of HOST2, JAK2, STAT3 and vimentin, and elevated the expression of E-cadherin. HOST2 silencing also decreased the levels of Snail, Slug and Twist but increased the level of Zeb1 protein, while the opposite findings were observed in the HOST2 mimic group. Conclusion: These results reveal a possible mechanism in HCC in which LncRNA HOST2 may increase EMT and enhance proliferation, invasion and metastasis of HCC cells via activation of the JAK2-STAT3 signaling pathway.