The tyrosine kinase inhibitor nintedanib activates SHP-1 and induces apoptosis in triple-negative breast cancer cells

Triple-negative breast cancer (TNBC) remains difficult to treat and urgently needs new therapeutic options. Nintedanib, a multikinase inhibitor, has exhibited efficacy in early clinical trials for HER2-negative breast cancer. In this study, we examined a new molecular mechanism of nintedanib in TNBC. The results demonstrated that nintedanib enhanced TNBC cell apoptosis, which was accompanied by a reduction of p-STAT3 and its downstream proteins. STAT3 overexpression suppressed nintedanib-mediated apoptosis and further increased the activity of purified SHP-1 protein. Moreover, treatment with either a specific inhibitor of SHP-1 or SHP-1-targeted siRNA reduced the apoptotic effects of nintedanib, which validates the role of SHP-1 in nintedanib-mediated apoptosis. Furthermore, nintedanib-induced apoptosis was attenuated in TNBC cells expressing SHP-1 mutants with constantly open conformations, suggesting that the autoinhibitory mechanism of SHP-1 attenuated the effects of nintedanib. Importantly, nintedanib significantly inhibited tumor growth via the SHP-1/p-STAT3 pathway. Clinically, SHP-1 levels were downregulated, whereas p-STAT3 was upregulated in tumor tissues, and SHP-1 transcripts were associated with improved disease-free survival in TNBC patients. Our findings revealed that nintedanib induces TNBC apoptosis by acting as a SHP-1 agonist, suggesting that targeting STAT3 by enhancing SHP-1 expression could be a viable therapeutic strategy against TNBC.

Effects of cucurmosin combined with common chemotherapeutics on proliferation and apoptosis of NB4 cells / 中国实验血液学杂志

This study was aimed to investigate the proliferation inhibition and apoptosis induction of cucurmosin (CUS) combined with all trans-retinoic acid (ATRA) or arsenic trioxide (ATO) on human acute promyelocytic leukemia cell line NB4. MTT method was used to determine the proliferative inhibition of CUS combined with ATRA or ATO on NB4 cells, and flow cytometry was used to determine the apoptosis induction effect of CUS combined with ATRA or ATO on NB4 cells. Jin's formula was used to assess the synergistic effect of this combinations. The results showed that, compared with single drug, the proliferation inhibitory ratio and apoptotic ratio of CUS combined with ATRA or ATO on NB4 cells was higher than CUS, ATRA and ATO alone. The synergistic index (q) were all larger than 0.85, and the combined effects were significant at low concentrations. It is concluded that the CUS combined with ATRA or ATO synergistically increases the effects of proliferative inhibition and apoptosis induction on NB4 cells.

Effects of cucurmosin on the cell proliferation and apoptosis in human pancreatic PANC-1 cells / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the effects of cucurmosin (CUS) on the cell proliferation and apoptosis in pancreatic PANC-1 cells.</p><p><b>METHODS</b>The inhibition of CUS on the PANC-1 cell growth was observed using MTT assay. The inhibition ratio of CUS on the pancreatic orthotopic transplantation was in vivo observed in the NOD/SCID mouse model. The changes of microstructure of the apoptosis-inducing effect of CUS on PANC-1 was observed under electron microscope. The cell cycle and apoptosis after CUS intervention was detected using flow cytometry. The Caspase-3 activity after CUS treatment was detected using enzyme linked immunospecific assay (ELISA).</p><p><b>RESULTS</b>Treatment with CUS at the dose of 0.125, 0.25, and 0.5 mg/kg inhibited the growth of pancreatic carcinoma PANC-1 xenografs with the ratio of 45.2%, 50.0%, and 59.7%, respectively (P < 0.05). After exposure to 10 microg/mL CUS for 24 h, most cells presented typical morphologic changes of apoptosis such as chromatin condensation and shrunken nucleus. The apoptotic cells increased. Some nuclear shrinkage and fragmentation, as well as the apoptotic body were observed when cells were exposed to CUS for 72 h. Being exposed to 0, 2.5, 10.0, and 40.0 microg/mL of the CUS for 72 h, the percentage of G0/G1 phase cells was 46.56% +/- 5.08%, 53.33% +/- 5.05%, 67.50% +/- 6.50%, and 77.00% +/- 6.73%, respectively (P < 0.05). The apoptosis ratio was 2.50% +/- 0.13%, 8.30% +/- 1.23%, 23.40% +/- 2.45%, and 48.50% +/- 3.65% shown by Annexin V/PI (P < 0.05). The Caspase-3 activity (unit) was 0.009 +/- 0.002, 0.011 +/- 0.003, 0.035 +/- 0.009, and 0.065 +/- 0.009, respectively (P < 0.05). These data showed that CUS induced the apoptosis of PANC-1 cells in a dose-dependent maner. Being exposed to 40.0 microg/mL of the CUS for 24, 48, and 72 h, the percentage of G0/ G1 phase cells was 56.60% +/- 6.65%, 67.83% +/- 6.76%, and 77.00% +/- 6.73%, respectively (P < 0.05), the apoptosis ratio was 16.51% +/- 2.97%, 38.51% +/- 2.38%, and 48.50% +/- 3.65% shown by Annexin V/PI (P < 0.05). These data showed that CUS induced apoptosis of PANC-1 cells in the G0/G1 phase of the cell cycle in a time-dependent maner.</p><p><b>CONCLUSION</b>CUS significantly inhibited the growth of PANC-1 cells possibly through the G0/G1 cell cycle arrest and apoptosis.</p>