Calcium/calmodulin-dependent kinase inhibitor induces growth inhibition, cell cycle arrest, and apoptosis in human choriocarcinoma cells

TR1 promotes cell proliferation and inhibits apoptosis through cyclin A and CTGF regulation in non-small cell lung cancer

The Hippo pathway plays a major role in development and organ size control, and its dysregulation contributes to tumorigenesis. WWTR1 is a transcription coactivator acting downstream of the Hippo pathway. Recently, WWTR1 has been reported to be overexpressed in several human cancers including lung cancer. However, the molecular mechanism of WWTR1 regulating lung cancer aggressiveness remains ambiguous. In the present study, we analyzed the expression of WWTR1 in NSCLC cell lines and found that WWTR1 was overexpressed at both the mRNA and protein levels. Knockdown of WWTR1 by siRNA interference in A549 cells significantly inhibited cell proliferation and increased paclitaxel-induced apoptosis. On the other side, WWTR1 overexpression in HBE cell line promoted cell proliferation and inhibited apoptosis. In addition, we found that the decreased proliferation after siRNA treatment was due to cell cycle arrest. Further analysis showed that WWTR1 could induce cyclin A, connective tissue growth factor (CTGF) expression, and inhibit caspase3 cleavage. In conclusion, WWTR1 promotes malignant cell growth and inhibits apoptosis by cyclin A and CTGF regulation.

The many faces of calmodulin in cell proliferation, programmed cell death, autophagy, and cancer

Calmodulin (CaM) is a ubiquitous Ca(2+) receptor protein mediating a large number of signaling processes in all eukaryotic cells. CaM plays a central role in regulating a myriad of cellular functions via interaction with multiple target proteins. This review focuses on the action of CaM and CaM-dependent signaling systems in the control of vertebrate cell proliferation, programmed cell death and autophagy. The significance of CaM and interconnected CaM-regulated systems for the physiology of cancer cells including tumor stem cells, and processes required for tumor progression such as growth, tumor-associated angiogenesis and metastasis are highlighted. Furthermore, the potential targeting of CaM-dependent signaling processes for therapeutic use is discussed.