Diosmetin enhances the sensitivity of radiotherapy by suppressing homologous recombination in endometrial cancer

Diosmetin: A dietary flavone as modulator of signaling pathways in cancer progression

Flavonoids, constituting the most extensive category of polyphenols, founds in a variety of plants and comprise over 9000 compounds. Diosmetin, O-methylated flavone (3',5,7-trihydroxy-4'-methoxyflavone) of flavonoid aglycone diosmin have witnessed a significant surge in recent years. Many studies showed that flavonoids induced cytotoxicity in different organ specific cancer types. Thus, current review evaluates the anticancer potential of diosmetin and shed light on its mechanism of action such as cell cycle regulation, apoptosis via both intrinsic and extrinsic pathway, autophagy and tumour progression and metastasis. It also provides comprehensive analysis of different cancer targets and their role in breast, colon, hepatic, gliomas, leukemia, lung, prostate and skin cancer. Combination studies of diosmetin to improve drug sensitivity and reduce toxicity towards normal cells has been also discussed. Besides, in vitro studies, present review also discuss the anticancer potential of diosmetin on xenograft mice model. Different natural sources of diosmetin, limitations, pharmacokinetic analysis and toxicity study also summarized in current review. The emphasis on enhancing solubility and permeability for clinical utility has been thoroughly highlighted with particular attention given to the utilization of nano formulations to overcome existing barriers. At last, in-depth analysis of current challenges and a forward-looking perspective deliberated to address the existing gaps and position it as a promising lead compound for clinical applications in cancer treatment. This discussion is boosted by diosmetin's potential anticancer properties on different cancers, makes valuable candidates in the ongoing quest for effective therapeutic interventions against cancer.

Diosmetin inhibits cell growth and proliferation by regulating the cell cycle and lipid metabolism pathway in hepatocellular carcinoma

Diosmetin (DSM), a newly discovered natural flavonoid, found in citrus plants and olive leaves, has been reported to inhibit the progression of cancer when used as a food supplement. This study aimed to investigate DSM's anti-hepatocellular carcinoma (HCC) properties and possible molecular mechanisms. Hep3B and HCCLM3 cells were selected to evaluate the anti-HCC properties of DSM in vitro. RNA sequencing (RNA-seq) was used to identify the possible molecular targets and pathways. Gas chromatography-mass spectrometry (GC-MS) was used to evaluate the effect of DSM treatment on the primary metabolites of HCCLM3 cells. Tumor xenograft was performed in nude mice to examine the anti-HCC properties of DSM in vivo. The results showed that DSM inhibited the proliferation and migration of HCC cells in vitro in a dose-dependent manner. RNA-seq identified 4459 differentially expressed genes (DEGs) that were highly enriched in the cell cycle pathway. In addition, DSM regulated cell growth by arresting the cell cycle in the G1 phase by decreasing the expression of BCL2, CDK1, and CCND1. Furthermore, metabolomics analysis revealed that DSM interfered with the lipid metabolism pathway of HCC cells by significantly inhibiting the synthesis of metabolites, such as acetic acid, decanoic acid, glycerol, and L-proline. Subcutaneous tumor formation experiments revealed that DSM significantly reduced the tumor volume and weight when compared to the control. Immunohistochemical analysis further revealed that DSM treatment significantly decreased the expression of the proliferative marker KI67. Our findings demonstrated that DSM exhibited antitumor effects on HCC cells by inhibiting cell proliferation via cell cycle arrest and interfering with lipid metabolism.

Valproic Acid Regulates HR and Cell Cycle Through MUS81-pRPA2 Pathway in Response to Hydroxyurea

Breast cancer is the primary problem threatening women’s health. The combined application of valproic acid (VPA) and hydroxyurea (HU) has a synergistic effect on killing breast cancer cells, but the molecular mechanism remains elusive. Replication protein A2 phosphorylation (pRPA2), is essential for homologous recombination (HR) repair and cell cycle. Here we showed that in response to HU, the VPA significantly decreased the tumor cells survival, and promoted S-phase slippage, which was associated with the decrease of pCHK1 and WEE1/pCDK1-mediated checkpoint kinases phosphorylation pathway and inhibited pRPA2/Rad51-mediated HR repair pathway; the mutation of pRPA2 significantly diminished the above effect, indicating that VPA-caused HU sensitization was pRPA2 dependent. It was further found that VPA and HU combination treatment also resulted in the decrease of endonuclease MUS81. After MUS81 elimination, not only the level of pRPA2 was abolished in response to HU treatment, but also VPA-caused HU sensitization was significantly down-regulated through pRPA2-mediated checkpoint kinases phosphorylation and HR repair pathways. In addition, the VPA altered the tumor microenvironment and reduced tumor burden by recruiting macrophages to tumor sites; the Kaplan-Meier analysis showed that patients with high pRPA2 expression had significantly worse survival. Overall, our findings demonstrated that VPA influences HR repair and cell cycle through down-regulating MUS81-pRPA2 pathway in response to HU treatment.