To Evaluate the Anti-Proliferative Role of Chenopodium album and Caralluma tuberculata Extracts in Triple Negative Breast Cancer

Abstract

Breast cancer refers to the aberrant proliferation of immature cells which will form lumps, affecting the production of normal breast cells. The over-expression and downregulation of one or two types of hormone receptors (ER, PR and HER2) are quite common in breast cancers. However, one type of breast cancer that is highly aggressive with various classifications shows worse prognosis and lacks the aforementioned major hormone receptors, named Triple Negative Breast Cancer (TNBC). Because of its aggressiveness and lack of three major receptors, available therapies are ineffective and chemotherapy is the only available option for its treatment. Because of heterogeneity, resistance, and relapse cases, researchers go for bioactive compounds from natural resources and use them against various cancers which shows effective results. Chenopodium album and Caralluma tuberculata are cacti species quite common in Asia and other regions of the world and have been involved in medicinal purposes for hundreds of years. Recently, the anti-proliferative role of both plant species and their bioactive compounds has been reported against solid tumors, though their anti-cancer effects on TNBCs remain unknown. The current study aimed at exploring the anti tumor potential of C. album and C. tuberculata against TNBC. MDA-MB-231 cell line was selected as the main TNBC model during this study. Cells were incubated at 37°C and 5% CO2 concentration before being treated with C. album and C. tuberculata extracts. Furthermore, we investigated the combined effect of the FDA approved treatment of breast cancers (Palbociclib) with both extracts, both in single and combined therapy. Moreover, the effect of C. album, C. tuberculata and Palbociclib on the expression of c-Myc and Eya3, as well as tumor suppressor genes (p16, p21 and p53) in MDA-MB-231 cells was examined via qPCR (both in single and combined treatments). Cell migration assay was additionally performed on MDA-MB-231 cells Abstract 2 following treatments with the above mentioned extracts and drug. Lastly, DNA fragmentation assay was performed to identify potential apoptotic properties of each extract. Both C. album and C. tuberculata extracts showed anti-proliferative effects against MDA-MB-231 cells, which were comparable to those induced by Palbociclib. Both extracts also displayed an additive effect when given in combination with Palbociclib in MDA-MB-231 cells. Expression analysis indicates the downregulation of Eya3 by both the extracts, but c-Myc shows decreased expression towards C. tuberculata and ineffective towards C. album. However, both extracts also notably caused downregulation of p16, p21 and p53 in single treatments. Whereas, the combined treatment of C. album extract with Palbociclib caused an increase in p16 and p53 expression. Both extracts, alone or in combination with Palbociclib, inhibited the migration and invasion of MDA-MB-231 cells. The apoptosis assay clearly indicates that both extracts are not involved in promoting apoptosis. Taken together, these results demonstrate a new role of these two plant extracts as a potent inhibitor in the case of Triple Negative Breast Cancer.