Shao‐Hsuan Kao

Deoxyshikonin triggers apoptosis in cervical cancer cells through p38 MAPK ‐mediated caspase activation

Abstract Deoxyshikonin (DSK) is a biological component derived from Lithospermum erythrorhizon . Although DSK possesses potential anticancer activities, whether DSK exerts anticancer effects on cervical cancer cells is incompletely explored. This study was aimed to investigate the anticancer activity of DSK against cervical cancer cells and its molecular mechanisms. Cell viability was evaluated by MTT assay. Level of phosphorylation and protein was determined using Western blot. Involvement of signaling kinases was assessed by specific inhibitors. Our results revealed that DSK reduced viability of human cervical cell in a dose‐dependent fashion. Meanwhile, DSK significantly elicited apoptosis of HeLa and SiHa cells. Apoptosis microarray was used to elucidate the involved pathways, and the results showed that DSK dose‐dependently diminished cellular inhibitor of apoptosis protein 1 (cIAP1), cIAP2, and XIAP, and induced cleavage of poly(ADP‐ribose) polymerase (PARP) and caspase‐8/9/3. Furthermore, we observed that DSK significantly triggered activation of ERK, JNK, and p38 MAPK (p38), and only inhibition of p38 diminished the DSK‐mediated pro‐caspases cleavage. Taken together, our results demonstrate that DSK has anti‐cervical cancer effects via the apoptotic cascade elicited by downregulation of IAPs and p38‐mediated caspase activation. This suggests that DSK could act as an adjuvant to facilitate cervical cancer management.

MTA2 silencing attenuates the metastatic potential of cervical cancer cells by inhibiting AP1-mediated MMP12 expression via the ASK1/MEK3/p38/YB1 axis

AbstractMetastasis-associated protein 2 (MTA2) is a transcription factor that is highly associated with matrix metalloproteinase 12 (MMP12). Thus, we hypothesized that MTA2 may regulate MMP12 expression and is involved in cervical cancer metastasis. Results showed that MTA2 and MMP12 were highly expressed in cervical cancer cells, and MTA2 knockdown reduced MMP12 expression and inhibited the metastasis of cervical cancer cells in xenograft mice. MMP12 knockdown did not influence the viability of cervical cancer cells but clearly inhibited cell migration and invasion both in vitro and in vivo. MMP12 was highly expressed in cervical tumor tissues and correlated with the poor survival rate of patients with cervical cancer. Further investigations revealed that p38 mitogen-activated protein kinase (p38), mitogen-activated protein kinase kinase 3 (MEK3), and apoptosis signal-regulating kinase 1 (ASK1) were involved in MMP12 downregulation in response to MTA2 knockdown. Results also demonstrated that p38-mediated Y-box binding protein1 (YB1) phosphorylation disrupted the binding of AP1 (c-Fos/c-Jun) to the MMP12 promoter, thereby inhibiting MMP12 expression and the metastatic potential of cervical cancer cells. Collectively, targeting both MTA2 and MMP12 may be a promising strategy for the treatment of cervical cancer.