MicroRNAs are noncoding regulatory RNAs strongly implicated in carcinogenesis, cell survival, and chemosensitivity. Here, microRNAs associated with chemoresistance in ovarian carcinoma, the most lethal of gynaecological malignancies, were identified and their functional effects in chemoresistant ovarian cancer cells were assessed. MicroRNA expression in paclitaxel (PTX)-resistant SKpac sublines was compared with that of the PTX-sensitive, parental SKOV3 ovarian cancer cell line using microarray and qRT–PCR. The function of differentially expressed microRNAs in chemoresistant ovarian cancer was further evaluated by apoptosis, cell proliferation, and migration assays. Upregulation of miR-106a and downregulation of miR-591 were associated with PTX resistance in ovarian cancer cells and human tumour samples. Transfection with anti-miR-106a or pre-miR-591 resensitized PTX-resistant SKpac cells to PTX by enhancing apoptosis (23 and 42% increase), and inhibited their cell migration (43 and 56% decrease) and proliferation (64 and 65% decrease). Furthermore, ZEB1 was identified as a novel target gene of miR-591, and BCL10 and caspase-7 were target genes of miR-106a, as identified by immunoblotting and luciferase assay. MiR-106a and miR-591 have important roles in conferring PTX resistance to ovarian cancer cells. Modulation of these microRNAs resensitizes PTX-resistant cancer cells by targeting BCL10, caspase-7, and ZEB1.

Src is considered a rising therapeutic target for the treatment of solid tumors, and Src family kinases (SFKs) participate in cancer cell proliferation and survival. The role of SFK suppression was investigated in the proliferation, migration, and invasion of pancreatic cancer cells. Knockdown of the SFKs in pancreatic cancer cells was achieved by transfecting small interfering RNAs, and its effects were investigated using proliferation, wound, and invasion assays. The SFK inhibitors suppressed proliferation and induced cell cycle arrest in pancreatic cancer cells. The SFK messenger RNA profiles showed that Yes1, Lyn, Fyn, Frk, Hck, and Src were expressed. Specific small interfering RNA transfection suppressed the messenger RNA expressions of Yes1, Lyn, Fyn, Frk, and Src, and the knockdown suppressed cell proliferation by 16.7% to 47.3% in PANC-1 cells. Knockdown of any of these 5 SFKs suppressed proliferation in other pancreatic cancer cell lines by 3.0% to 40.5%. The knockdowns significantly reduced pancreatic cancer cell migration by 24.9% to 66.7% and completely inhibited invasion. These results suggest that the knockdown of Yes1, Lyn, Fyn, Frk, or Src reduce human pancreatic cancer cell proliferation, migration, and invasion, and that SFKs should be viewed as critical therapeutic targets of pancreatic cancer.

Objectives: The aim of this study was to investigate the effects of the activated P2X₇ receptors on the proliferation and growth of human pancreatic cancer cells. Methods: Proliferation was measured by incorporating bromodeoxyuridine into pancreatic cancer cells, MIA PaCa-2 and HPAC. Expression of P2 receptors and signal molecules was examined using quantitative reverse transcription/polymerase chain reaction and/or Western blot. Proliferative effects of the P2X₇ receptors in vivo were examined using a xenotransplant model of pancreatic cancer cell lines. Results: Incubating pancreatic cancer cells with adenosine triphosphate (ATP) and 2′(3′)-O-(4-Benzoylbenzoyl)ATP resulted in a dose-dependent increase of cell proliferation. The P2 receptor antagonist, KN-62, and small interfering RNA against P2X₇ receptors, significantly decreased the proliferative effects of ATP. The ATP-induced proliferation was mediated by protein kinase C, extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), and c-Jun N-terminal kinase (JNK); specifically, ATP increased the phosphorylation of ERK1/2 and JNK. The expression of inducible nitric oxide synthase was decreased by P2X₇ receptor activation. In a xenotransplant model, applying ATP significantly increased the growth of induced tumors. Conclusions: The P2X₇ receptor activation by extracellular nucleotides increased proliferation and growth of human pancreatic cancer cells via ERK1/2 and JNK. This supports the pathophysiological role of P2X₇ receptors in pancreatic disease and recovery.

Lung cancer is the second most common cancer in the United States and the leading cause of mortality in cancer patients. Biomarkers predicting survival of patients with lung cancer have a profound effect on patient prognosis and treatment. However, predictive biomarkers for survival and their relevance for lung cancer are not been well known yet. The objective of this study was to perform machine learning with data from The Cancer Genome Atlas of patients with lung adenocarcinoma (LUAD) to find survival-specific gene mutations that could be used as survival-predicting biomarkers. To identify survival-specific mutations according to various clinical factors, four feature selection methods (information gain, chi-squared test, minimum redundancy maximum relevance, and correlation) were used. Extracted survival-specific mutations of LUAD were applied individually or as a group for Kaplan-Meier survival analysis. Mutations in MMRN2 and GMPPA were significantly associated with patient mortality while those in ZNF560 and SETX were associated with patient survival. Mutations in DNAJC2 and MMRN2 showed significant negative association with overall survival while mutations in ZNF560 showed significant positive association with overall survival. Mutations in MMRN2 showed significant negative association with disease-free survival while mutations in DRD3 and ZNF560 showed positive associated with disease-free survival. Mutations in DRD3, SETX, and ZNF560 showed significant positive association with survival in patients with LUAD while the opposite was true for mutations in DNAJC2, GMPPA, and MMRN2. These gene mutations were also found in other cohorts of LUAD, lung squamous cell carcinoma, and small cell lung cancer. In LUAD of Pan-Lung Cancer cohort, mutations in GMPPA, DNAJC2, and MMRN2 showed significant negative associations with survival of patients while mutations in DRD3 and SETX showed significant positive association with survival. In this study, machine learning was conducted to obtain information necessary to discover specific gene mutations associated with the survival of patients with LUAD. Mutations in the above six genes could predict survival rate and disease-free survival rate in patients with LUAD. Thus, they are important biomarker candidates for prognosis.

Background: Epstein-Barr virus (EBV) infection immortalizes primary B cells in vitro and generates lymphoblastoid cell lines (LCLs), which are used for several purposes in immunological and genetic studies. Purinergic receptors, consisting of P2X and P2Y, are activated by extracellular nucleotides in most tissues and exert various physiological effects. In B cells, especially EBV-induced LCLs, their expression and function have not been well studied. We investigated the expression of P2 receptors on primary human B cells and LCLs using the quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) method for revealing the gene expression profile of the P2 receptor subtypes and their changes during transformation.Results: The mRNA transcripts of most P2 receptors were detected in primary B cells; the expression of P2X₃and P2X₇receptors was the lowest of all the P2 receptors. By contrast, LCLs expressed several dominant P2 receptors – P2X₄, P2X₅, and P2Y₁₁– in amounts similar to those seen in B cells infected with EBV for 2 weeks. The amount of most P2 subtypes in LCLs or EBV-infected B cells was lower than in normal B cells. However, the amount of P2X₇receptor expressed in LCLs was higher. Protein expression was studied using Western blotting to confirm the mRNA findings for P2X₁, P2X₄, P2X₇, P2Y₁, and P2Y₁₁receptors. ATP increased the intracellular free Ca²⁺concentration ([Ca²⁺]_i) by enhancing the Ca²⁺influx in both B cells and LCLs in a dose-dependent manner.Conclusion: These findings describe P2 receptor expression profiles and the effects of purinergic stimuli on B cells and suggest some plasticity in the expression of the P2 receptor phenotype. This may help explain the nature and effect of P2 receptors on B cells and their role in altering the characteristics of LCLs.