A traditional gynecological medicine inhibits ovarian cancer progression and eliminates cancer stem cells via the LRPPRC-OXPHOS axis.

BACKGROUND: Ovarian cancer (OC) is the most lethal malignant gynecological tumor type for which limited therapeutic targets and drugs are available. Enhanced mitochondrial oxidative phosphorylation (OXPHOS), which enables cell growth, migration, and cancer stem cell maintenance, is a critical driver of disease progression and a potential intervention target of OC. However, the current OXPHOS intervention strategy mainly suppresses the activity of the electron transport chain directly and cannot effectively distinguish normal tissues from cancer tissues, resulting in serious side effects and limited efficacy. METHODS: We screened natural product libraries to investigate potential anti-OC drugs that target OXPHOS. Additionally, LC-MS, qRT-PCR, western-blot, clonogenic assay, Immunohistochemistry, wound scratch assay, and xenograft model was applied to evaluate the anti-tumor mechanism of small molecules obtained by screening in OC. RESULTS: Gossypol acetic acid (GAA), a widely used gynecological medicine, was screened out from the drug library with the function of suppressing OXPHOS and OC progression by targeting the leucine-rich pentatricopeptide repeat containing (LRPPRC) protein. Mechanically, LRPPRC promotes the synthesis of OXPHOS subunits by binding to RNAs encoded by mitochondrial DNA. GAA binds to LRPPRC directly and induces LRPPRC rapid degradation in a ubiquitin-independent manner. LRPPRC was overexpressed in OC, which is highly correlated with the poor outcomes of OC and could promote the malignant phenotype of OC cells in vitro and in vivo. GAA management inhibits cell growth, clonal formation, and cancer stem cell maintenance in vitro, and suppresses subcutaneous graft tumor growth in vivo. CONCLUSIONS: Our study identified a therapeutic target and provided a corresponding inhibitor for OXPHOS-based OC therapy. GAA inhibits OC progression by suppressing OXPHOS complex synthesis via targeting LRPPRC protein, supporting its potential utility as a natural therapeutic agent for ovarian cancer.

Shikonin and cisplatin synergistically overcome cisplatin resistance of ovarian cancer by inducing ferroptosis via upregulation of HMOX1 to promote Fe2+ accumulation.

BACKGROUND: Cisplatin-based chemotherapy often results in ovarian cancer (OC) chemical resistance and treatment failure. The combination of natural compounds with platinum-based agents is a new strategy for overcoming cisplatin resistance. At present, the synergistic effects and mechanism of combination of shikonin and cisplatin to overcome cisplatin resistance in OC are still unknown. PURPOSE: This study was to evaluate the synergistic effects of shikonin and cisplatin on cisplatin-resistant OC cells and to assess the underlying molecular basis for these effects. METHODS: Cell counting kit-8 assay, colony-formation assay, proteomic analysis, reactive oxygen species (ROS) detection, lipid peroxidation (LPO) detection, Fe2+ detection, western blot, and quantitative real-time reverse transcription PCR (qRT-PCR) were performed to evaluate the effects of shikonin and cisplatin on cisplatin-resistant OC cells. Underlying mechanisms of action were investigated in vitro using small molecule inhibitors and siRNA. In vivo, the effect of shikonin and cisplatin combination on tumor growth in BALB/c nude mice was evaluated, with tumor immunohistochemical (IHC) staining performed to detect ferroptosis-related proteins. RESULTS: In vitro, shikonin and cisplatin were shown to synergistically reduce the viability of cisplatin-resistant OC cells. Proteomic results demonstrated that the combination of the two drugs induced a ferroptotic process, as evidenced by increased levels of ROS, LPO, and Fe2+, with downregulation of glutathione peroxidase 4 (GPX4). Heme oxygenase 1 (HMOX1) inhibition and siRNA interference attenuated the combined effect of the two drugs on cell viability. Accumulation of Fe2+ was attenuated by siRNA interference of HMOX1. In vivo, combination treatment significantly inhibited the growth of subcutaneous tumors in BALB/c nude mice and increased the expression of ferroptosis-related proteins in tumor tissue. CONCLUSION: We report for the first time that the co-treatment of shikonin and cisplatin overcomes cisplatin resistance in OC through ferroptosis. Mechanistic analysis reveals the co-treatment induces ferroptosis through upregulation of HMOX1 that promotes Fe2+ accumulation.

The inhibitory effect of Shaoyao Ruangan formula on mice with transplanted H22 hepatocarcinoma and its mechanism research.

BACKGROUND: The incidence of hepatocellular carcinoma (HCC) is very high in the world. However, a safe and effective strategy is still under research. AIMS: Our aim was to demonstrate the inhibitory effect of Shaoyao Ruangan Formmula (SRF) on the tumor of H22-bearing mice and explore its antitumor mechanisms. SETTINGS AND DESIGN: Corresponding physiological indexes of H22-bearing mice treated with SRF were compared with that of saline treated mice, which could reflect the tumor-suppressing effect of SRF. MATERIALS AND METHODS: After treatment, tumor weight, survival time, related gene expression levels etc., were recorded or detected. STATISTICAL ANALYSIS: Data analyzed using a computer SPSS program. RESULTS AND CONCLUSIONS: Comparing with blank control group, the tumor inhibitor rate (IR) of low, middle and high dose group of SRF was 17.72%, 33.99% and 23.73%, respectively. IR of CTX was 43.95%. The results also showed that each group of SRF could prolong the life span of H22-bearing mice to some extent. In addition, reverse transcription polymerase chain reaction (RT-PCR) results revealed that SRF was able to influence related genes expression in the tumor tissues of H22-bearing mice. The expression of TGF-ß receptor type II (TBRII) gene was significantly upregulated in each SRF group comparing with normal saline group. On the contrary, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) was significantly downregulated in each SRF group comparing with normal saline group. In summary, SRF showed tumor-suppressing effect on mice with transplanted H22 hepatocarcinoma. The mechanism of antitumor effect may induced by upregulating TBRII expression and down-regulating NF-κB expression.