Efficacy and safety of cinobufacini injection combined with vinorelbine and cisplatin regimen chemotherapy for stage III/IV non-small cell lung cancer: A protocol for systematic review and meta-analysis of randomized controlled trials

Isolation, Identification and Chemical Modification of Bufadienolides from Bufo melanostictus Schneider and Their Cytotoxic Activities against Prostate Cancer Cells

The traditional Chinese medicine toad venom (Venenum bufonis) has been extensively used to treat various diseases, including cancers, in China and other Southeast Asian countries. The major constituents of toad venom, e.g., bufadienolides and alkaloids, exhibit broad-spectrum pharmacological effects in cancers. Herein, two new bufadienolides (1 and 2), along with eleven known compounds (3-13) were successfully isolated from Bufo melanostictus Schneider. Their structures were elucidated by extensive spectroscopic data and X-ray diffraction analysis. Furthermore, four lactam derivatives were synthesized through the transformation of bufadienolides lactones. The inhibitory effects of these compounds against human prostate cancer cell lines PC-3 and DU145 were evaluated. The outcomes indicated a notable trend, with a substantial subset displaying nanomolar range IC50 values against PC-3 and DU145 cells, underscoring their pronounced cytotoxicity. Moreover, a noteworthy distinction surfaces, wherein lactones consistently outperformed their lactam counterparts, further validating their heightened potency for the treatment of prostate cancer. This study contributes significant preclinical evidence substantiating the therapeutic viability of bufadienolides and toad venom as intervention strategies for prostate cancer.

Na, K-ATPase α1 cooperates with its endogenous ligand to reprogram immune microenvironment of lung carcinoma and promotes immune escape

Dysregulated endocrine hormones (EHs) contribute to tumorigenesis, but how EHs affect the tumor immune microenvironment (TIM) and the immunotherapy of non-small cell lung cancer (NSCLC) is still unclear. Here, endogenous ouabain (EO), an adrenergic hormone, is elevated in patients with NSCLC and closely related to tumor pathological stage, metastasis, and survival. EO promotes the suppression of TIM in vivo by modulating the expression of immune checkpoint proteins, in which programmed cell death protein ligand 1 (PD-L1) plays a major role. EO increases PD-L1 transcription; however, the EO receptor Na- and K-dependent adenosine triphosphatase (Na, K-ATPase) α1 interacts with PD-L1 to trigger the endocytic degradation of PD-L1. This seemingly contradictory result led us to discover the mechanism whereby EO cooperates with Na, K-ATPase α1 to finely control PD-L1 expression and dampen tumoral immunity. In conclusion, the Na, K-ATPase α1/EO signaling facilitates immune escape in lung cancer, and manipulation of this signaling shows great promise in improving immunotherapy for lung adenocarcinoma.

Cinobufagin Is a Selective Anti-Cancer Agent against Tumors with EGFR Amplification and PTEN Deletion

Glioblastoma multiforme (GBM) is the most common and malignant brain tumor, and almost half of the patients carrying EGFR-driven tumor with PTEN deficiency are resistant to EGFR-targeted therapy. EGFR amplification and/or mutation is reported in various epithelial tumors. This series of studies aimed to identify a potent compound against EGFR-driven tumor. We screened a chemical library containing over 600 individual compounds purified from Traditional Chinese Medicine against GBM cells with EGFR amplification and found that cinobufagin, the major active ingredient of Chansu, inhibited the proliferation of EGFR amplified GBM cells and PTEN deficiency enhanced its anti-proliferation effects. Cinobufagin also strongly inhibited the proliferation of carcinoma cell lines with wild-type or mutant EGFR expression. In contrast, the compound only weakly inhibited the proliferation of cancer cells with low or without EGFR expression. Cinobufagin blocked EGFR phosphorylation and its downstream signaling, which additionally induced apoptosis and cytotoxicity in EGFR amplified cancer cells. In vivo, cinobufagin blocked EGFR signaling, inhibited cell proliferation, and elicited apoptosis, thereby suppressing tumor growth in both subcutaneous and intracranial U87MG-EGFR xenograft mouse models and increasing the median survival of nude mice bearing intracranial U87MG-EGFR tumors. Cinobufagin is a potential therapeutic agent for treating malignant glioma and other human cancers expressing EGFR.