Identification of two novel thiophene analogues as inducers of autophagy mediated cell death in breast cancer cells

Anticancer Effect of Tanshinones on Female Breast Cancer and Gynecological Cancer

Female breast cancer, ovarian cancer, cervical cancer, and endometrial cancer are the most common tumors and the most common causes of cancer-related mortality worldwide in women. Drugs derived from natural plants play important roles in malignant tumor therapy. Salvia miltiorrhiza is a commonly used Chinese herb which has been used in the treatment of liver diseases and cardiovascular diseases because of its positive effect of promoting blood circulation, increasing oxidative stress, and removing blood stasis. Recently, studies have found that fat-soluble components of Salvia miltiorrhiza such as tanshinone II, tanshinone I, cryptotanshinone, and dihydrotanshinone I displayed good antitumor activity in vivo and in vitro for gynecological cancer by different molecular mechanisms. In this study, the latest research progress on the antitumor effect and mechanism of tanshinone compounds in breast cancer and gynecological cancer was reviewed to provide references for the research and clinical application of these compounds (tanshinone II, tanshinone I, cryptotanshinone, and dihydrotanshinone I).

The Synergistic Effects of Celastrol in combination with Tamoxifen on Apoptosis and Autophagy in MCF-7 Cells

Breast cancer is one of the most common cancers among females and is associated with high mortality and morbidity rates. Several studies have demonstrated that combination treatments with natural products and tamoxifen can improve the sensitivity and cytotoxicity of oestrogen-positive breast cancer cells in response to tamoxifen. Celastrol, a triterpene from traditional Chinese medicine, has been proven to exert significant anticancer effects on various cancers. Our study is aimed at exploring the interactive antitumour effects of celastrol combined with tamoxifen and the potential underlying anticancer mechanisms in MCF-7 cells. The results from MTT assays, isobolographic analyses, and clonogenic cell survival assays revealed that a combination of celastrol and tamoxifen exerted synergistic cytotoxic effects in MCF-7 cells. The results from Annexin V/PI staining and flow cytometry analysis suggested that celastrol enhanced tamoxifen-mediated apoptosis. In addition, exposure to a combination of celastrol and tamoxifen inhibited cell proliferation by causing G1 phase cell cycle arrest. Moreover, the distribution of LC3 was monitored by immunofluorescence, and the changes in the LC3II and P62 levels detected by western blot analysis suggested that celastrol in combination with tamoxifen triggered autophagy. Furthermore, the decrease in p-Akt and p-mTOR in MCF-7 cells, along with the increase in the autophagy marker proteins LC3II and P62, suggested that the Akt/mTOR pathway might be involved in the triggering of cell autophagy by the combination treatment. However, in an MCF-7-implanted nude mouse model, it was possible to detect significantly decreased tumour volumes and tumour weights and decreased p-Akt and p-mTOR protein expression in the celastrol+tamoxifen group. Therefore, our study provides the first evidence that celastrol combined with tamoxifen exerts synergistic anticancer effects by inducing apoptosis and autophagy in MCF-7 cells. Considering the urgent need for novel therapeutic strategies in anticancer therapy, this combinatorial approach is worthy of further investigation.