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Purpose: One third of patients with diffuse large B-cell lymphoma (DLBCL) succumb to the disease partly due to rituximab resistance. Rituximab-induced calcium flux is an important inducer of apoptotic cell death, and we investigated the potential role of calcium channels in rituximab resistance. Experimental Design: The distinctive expression of calcium channel members was compared between patients sensitive and resistant to rituximab, cyclophosphamide, vincristine, doxorubicin, prednisone (RCHOP) regimen. The observation was further validated through mechanistic in vitro and in vivo studies using cell lines and patient-derived xenograft mouse models. Results: A significant inverse correlation was observed between CACNA1C expression and RCHOP resistance in two independent DLBCL cohorts, and CACNA1C expression was an independent prognostic factor for RCHOP resistance after adjusting for International Prognostic Index, cell-of-origin classification, and MYC/BCL2 double expression. Loss of CACNA1C expression reduced rituximab-induced apoptosis and tumor shrinkage. We further demonstrated direct interaction of CACNA1C with CD20 and its role in CD20 stabilization. Functional modulators of L-type calcium channel showed expected alteration in rituximab-induced apoptosis and tumor suppression. Furthermore, we demonstrated that CACNA1C expression was directly regulated by miR-363 whose high expression is associated with worse prognosis in DLBCL. Conclusions: We identified the role of CACNA1C in rituximab resistance, and modulating its expression or activity may alter rituximab sensitivity in DLBCL.

The onset of local invasion and lymphatic metastasis in pancreatic cancer limits survival following surgical intervention and additional therapies. Reduced expression of KiSS-1 in pancreatic cancer is associated with cancer metastasis. Previous studies have indicated that kisspeptin, the KiSS-1 peptide, is able to bind to its receptor-GPR54 (hOT7T175) and suppress the migration of PANC-1 pancreatic cancer cells. Whether the metastatic suppression of KiSS-1 is dependent on the levels of GPR54 in pancreatic cancer cell lines remains unclear. Human BxPC-3 pancreatic carcinoma cells are highly differentiated without exhibiting metastasis, however PANC-1 pancreatic carcinoma cells are poorly differentiated and exhibit local and lymph node metastasis. Compared with primary cultured trophoblasts, BxPc-3 and PANC-1 cells were observed to express low levels of KiSS-1 mRNA and protein, measured using reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. However, greater mRNA and protein expression levels of GPR54 were observed in PANC-1 cells compared with BxPc-3 cells. An MTT assay was used to investigate the effect of KiSS-1 on BxPc-3 and PANC-1 cell proliferation. There were no significant differences in proliferation following transfection with KiSS-1 in BxPc-3 and PANC-1 cells compared with the controls (P>0.05). A Transwell assay with chambers coated with Matrigel was used to evaluate the in vitro invasive ability of BxPc-3 and PANC-1 cells, with the invasion index of BxPc-3 and PANC-1 cells significantly reduced following 48 h of KiSS-1 overexpression (P0.05). KiSS-1 is a metastasis suppressor gene of pancreatic cancer, and this suppression is not dependent on the expression levels of GPR54. Therefore, KiSS-1 is potentially a novel target for gene therapy.

MYC2 is a core transcription factor in the plant response to jasmonates. It also functions in secondary metabolism and various processes for growth and development. However, the knowledge about its role in Salvia miltiorrhiza is still very limited. We determined that the biosynthesis of salvianolic acid B (Sal B) was strongly induced in 2-month-old transgenic plants that over-expressed SmMYC2. In the roots of transgenic line 12 that over-expressed SmMYC2 (OEM-12), the Sal B concentration was as high as 5.95 ± 0.07 mg g-1, a level that was 1.88-fold higher than that in control plants that had been transformed with an empty vector. Neither tanshinone IIA nor cryptotanshinone was detected by high-performance liquid chromatography in any of the genotypes. Global transcriptomic analysis using RNA sequencing revealed that most enzyme-encoding genes for the phenylpropanoid biosynthesis pathway were up-regulated in the overexpression lines. Furthermore, both the phenylalanine and tyrosine biosynthesis pathways were activated in those transgenics. Our data demonstrate that overexpression of SmMYC2 promotes the production of phenolic acids by simultaneously activating both primary and secondary pathways for metabolism in S. miltiorrhiza.

It has been reported that Annexin A2 (ANXA2) is up-regulated in hepatocellular carcinoma (HCC), but the roles of ANXA2 in the migration and invasion of HCC cells have not been determined. In this study, we found that ANXA2-specific siRNA (si-ANXA2) significantly inhibited the migration and invasion of HCC cells co-cultured with fibroblasts in vitro. In addition, the production of MMP-2 by fibroblasts cultured in supernatant collected from si-ANXA2-transfected HCC cells was notably down-regulated. ANXA2 was also found to be co-localized and co-immunoprecipitated with CD147. Further investigation revealed that the expression of ANXA2 in HCC cells affected the shedding of CD147-harboring membrane microvesicles, acting as a vehicle for CD147 in tumor-stromal interactions and thereby regulating the production of MMP-2 by fibroblasts. Together, these results suggest that ANXA2 enhances the migration and invasion potential of HCC cells in vitro by regulating the trafficking of CD147-harboring membrane microvesicles.