SH003 Enhances the Anti-cancer Effects of Dabrafenib on Lung Cancer Harboring BRAF G469A Mutation by Inhibiting the MAPK Signaling Pathway.

BACKGROUND/AIM: BRAF mutations are relatively uncommon in lung cancer. However, the majority of therapies targeting BRAF mutations have been developed exclusively for lung cancer patients with V600E mutations, limiting their effectiveness in treating tumors with the non-V600E BRAF mutations. As a result, there is a need to explore effective therapeutic strategies for patients with lung cancer carrying non-V600 BRAF mutations. Therefore, this study aims to identify a combination treatment approach that effectively targets lung cancer with G469A non-V600 BRAF alteration. MATERIALS AND METHODS: The efficacy of drug treatments was assayed using a patient-derived xenograft (PDX) mouse model. Histological analysis was performed using hematoxylin and eosin and immunohistochemical staining. Cell viability and growth were determined using the WST-8 and colony formation assays. Protein levels and apoptosis were analyzed using western blot and flow cytometry, respectively. RESULTS: We demonstrated that the lung cancer cells harboring the non-V600E G469A mutation were responsive to the combination of SH003 and dabrafenib. By utilizing patient-derived xenograft (PDX) models, we identified that this combined treatment induces apoptosis and exhibits antitumor effects through the reduction of ERK signals. The synergistic effect of the combination treatment on BRAF G469A lung cancer cells was consistent with its effects on PDX models, suggesting that the molecular mechanism of apoptosis involves a decrease in the MEK/ERK signaling pathway. CONCLUSION: The SH003 and dabrafenib combination can be potentially developed as an effective treatment strategy for addressing lung cancer patients with the BRAF G469A mutation.

SH003 Causes ER Stress-mediated Apoptosis of Breast Cancer Cells via Intracellular ROS Production.

BACKGROUND/AIM: Breast cancer is one of the most common cancers in women all over the world and new treatment options are urgent. ER stress in cancer cells results in apoptotic cell death, and it is being proposed as a new therapeutic target. SH003, a newly developed herbal medicine, has been reported to have anti-cancer effects. However, its molecular mechanism is not yet clearly defined. MATERIALS AND METHODS: Microarray was performed to check the differential gene expression patterns in various breast cancer cell lines. Cell viability was measured by MTT assays to detect cytotoxic effects. Annexin V-FITC and 7AAD staining, TUNEL assay and DCF-DA staining were analyzed by flow cytometry to evaluate apoptosis and ROS levels, respectively. Protein expression was examined in SH003-breast cancer cells using immunoblotting assays. The expression of C/EBP Homologous Protein (CHOP) mRNA was measured by real-time PCR. The effects of CHOP by SH003 treatment were investigated using transfection method. RESULTS: Herein, we investigated the molecular mechanisms through which SH003 causes apoptosis of human breast cancer cells. Both cell viability and apoptosis assays confirmed the SH003-induced apoptosis of breast cancer cells. Meanwhile, SH003 altered the expression patterns of several genes in a variety of breast cancer cell lines. More specifically, it upregulated gene sets including the response to unfolded proteins, independently of the breast cancer cell subtype. In addition, SH003-induced apoptosis was due to an increase in ROS production and an activation of the ER stress-signaling pathway. Moreover, CHOP gene silencing blocked SH003-induced apoptosis. CONCLUSION: SH003 causes apoptosis of breast cancer cells by upregulating ROS production and activating the ER stress-mediated pathway. Thus, our findings suggest that SH003 can be a potential therapeutic agent for breast cancer.