Xiaoting Hong

Obesity remains a global health challenge, with limited therapeutic options. Berberine (BBR) shows promise as an anti-obesity agent. However, its clinical application is hampered by modest efficacy and poor bioavailability. This study investigated the anti-obesity effects and underlying mechanisms of B12, a novel BBR derivative with enhanced solubility and bioavailability. Mice with obesity induced by a high-fat-diet were employed to evaluate B12's effect on weight loss. Energy expenditure was assessed using metabolic cages. Adipose tissue morphology was examined through histological analysis. In vitro studies were conducted using 3T3-L1 preadipocytes and immortalized brown adipocytes. Gene and protein expression were analyzed using RT-qPCR, western blotting, and immunohistochemistry. Cell cycle progression was evaluated by flow cytometry. B12 demonstrated anti-obesity efficacy superior to BBR, manifesting through dual mechanisms. It enhanced energy expenditure by increasing brown adipocyte numbers and UCP1 expression through SIRT1 upregulation and AMPK phosphorylation. Furthermore, B12 markedly reduced the mass of white adipose tissue in mice with HFD-induced obesity and inhibited adipocyte differentiation and lipid accumulation in 3T3-L1 preadipocytes. This effect was achieved through intervention at multiple stages: early-stage downregulation of CyclinD1 and C/EBPβ, followed by reduced expression and heterodimerization of RXRα and PPARγ during middle and late stages of differentiation, collectively preventing matural adipocyte formation. Our findings establish B12 as a promising anti-obesity agent, offering significantly enhanced efficacy over its parent compound BBR. This natural product-derived therapeutic candidate, with its improved pharmacological properties and dual mechanism of action, represents a significant advance in phytomedicine-based approaches to obesity treatment.

N6-methyladenosine (m6A) represents the most abundant internal RNA modification, and a key regulator of gene expression, yet its role in determining cell fate decisions such as senescence remains largely unexplored. Here, we identify the nuclear m6A reader YTHDC1 as a critical regulator of telomere homeostasis and senescence evasion in ovarian cancer. YTHDC1 expression was markedly elevated in advanced-stage tumors and correlated with poor patient survival. Functional investigation demonstrated that YTHDC1 ablation induced profound proliferative arrest and established a canonical senescence landscape. Mechanistic dissection revealed that YTHDC1 directly recognizes m6A-modified TERT transcripts, thereby stabilizing telomerase mRNA and maintaining telomere homeostasis. YTHDC1 knockdown triggered telomerase dysfunction and accelerated telomere shortening. Genetic restoration of TERT effectively reversed both the proliferative defects and senescence phenotypes induced by YTHDC1 deficiency. Significantly, YTHDC1-depleted senescent cells displayed enhanced sensitivity to the senolytic agent, ABT-263. Collectively, these findings uncover a previously unrecognized epitranscriptomic–telomerase axis that dictates senescence escape, establishing YTHDC1 as a central node linking RNA modification to telomere maintenance, cellular senescence, and tumor progression.

Background: For most colorectal cancer (CRC) patients, expanding the benefits of immunotherapy, particularly through blocking programmed cell death-1 (PD-1) and its ligand (PD-L1), is crucial, especially in cases with limited response to neoadjuvant therapy. This study investigates the role of Myoferlin (MYOF) as a novel target in CRC immunotherapy. Methods: Human CRC cell lines (RKO, HCT116), normal intestinal epithelial cells (HIEC-6), and the murine CRC cell line MC38 were used to study the effects of apatinib and MYOF in CRC cells. RNA sequencing, the CPTAC and TCGA databases, and other molecular and cellular methods were applied to disclose the mechanisms involved. A series of mouse models were established to assess the effects of apatinib and MYOF knockdown on tumor progression, immune cell infiltration, and immune checkpoint protein response. Results: We found that MYOF is overexpressed in CRC and linked to immune cell infiltration and checkpoint expression. Suppression of MYOF expression significantly inhibited CRC cell proliferation and migration, as well as reduced PD-L1 protein levels. Integrative analysis showed that apatinib modulates MYOF expression via VEGFR2, resulting in decreased PD-L1 expression, increased CD8+ T cell infiltration, and reduced pro-tumor M2 macrophages. Animal experiments further revealed that apatinib treatment or MYOF knockdown enhanced the efficacy of immune checkpoint blockade (ICB) in CRC. Conclusions: These findings highlight novel antitumor mechanisms of MYOF and suggest that combining apatinib with ICB therapy may improve CRC treatment outcomes, offering a promising strategy to enhance immune responses.

Pancreatic cancer (PC) is an aggressive and fatal malignant tumor, and exosomes have been reported to be closely related to PC invasion and metastasis. Here we found that Exo70, a key subunit of the exocyst complex, promoted PC metastasis by regulating the secretion of tumor exosomes. Clinical sample studies showed that Exo70 was highly expressed in PC and negatively correlated with patients’ survival. Exo70 promoted PC cell lines’ invasion and migration. Interestingly, knockdown of Exo70, or using an Exo70 inhibitor (ES2) inhibited the secretion of tumor exosomes and increased the accumulation of cellular vesicles. Furthermore, Exo70 was found to accumulate in the exosomes, which then fused with neighboring PC cells and promoted their invasion. Moreover, Exo70 increased the expression of exosomal PD-L1, leading to the immune escape of PC cells. In vivo, knockdown of Exo70 or treatment with ES2 both decreased the tumor metastasis of PC cells in mice. This study provides new insight into the mechanism of invasion and metastasis in PC and identifies Exo70 as a potential prognostic factor and therapeutic target for PC.

The identification of the prognostic markers and therapeutic targets might benefit the diagnosis and treatment of pancreatic adenocarcinoma (PAAD), one of the most aggressive malignancies. Vacuolar protein sorting associated protein 26 A (VPS26A) is a candidate prognosis gene for hepatocellular carcinoma, but its expression and function in PAAD remain unknown. The mRNA and protein expression of VPS26A in PAAD was explored and validated by bioinformatics and immunohistochemical analysis. The correlation between VPS26A expression and various clinical parameters, genetic status, diagnostic and prognostic value, survival and immune infiltration were evaluated, and the co-expressed gene-set enrichment analysis for VPS26A was performed. Cytologic and molecular experiments were further carried out to investigate the role and potential mechanism of VPS26A in PAAD. The mRNA and protein levels of VPS26A were elevated in PAAD tissues. High VPS26A expression was associated with the advanced histological type, tumor stage simplified, smoking status and tumor mutational burden score, and the poor prognosis of PAAD patients. VPS26A expression was significantly correlated with immune infiltration and immunotherapy response. VPS26A-co-expressed genes were mainly enriched in the regulation of cell adhesion and actin cytoskeleton and the immune-response-regulating signaling pathway. Our experiments further demonstrated that VPS26A promoted the proliferation, migration and invasion potentials of PAAD cell lines through activating the EGFR/ERK signaling. Our study suggested that VPS26A could be a potential biomarker and a therapeutic target for PAAD through comprehensive regulation of its growth, migration and immune microenvironment.

Antiangiogenic therapy is an important treatment strategy for metastatic colorectal cancer (mCRC). We carried out a clinical study of low-dose apatinib (250 mg) monotherapy as a third-line treatment in patients with mCRC and assessed its efficacy and safety. It demonstrated that low-dose apatinib had comparable survival outcomes, significantly improved the patient quality of life, and caused tolerable adverse reactions. To further investigate the underlying mechanism of the effects of apatinib in CRC besides angiogenesis, we performed RNA-seq, and our results suggested that apatinib may have other potential antitumor mechanisms in CRC through multiple pathways, including exosomes secretion. In RKO and HCT116 cells, apatinib significantly reduced exosomes secretion by targeting multivesicular body (MVB) transport. Further studies have indicated that apatinib not only promoted the degradation of MVBs via the regulation of LAMP2 but also interfered with MVB transport by inhibiting Rab11 expression. Moreover, apatinib inhibited MVB membrane fusion by reducing SNAP23 and VAMP2 expression. In vivo, apatinib inhibited orthotopic murine colon cancer growth and metastasis and reduced the serum exosomes amount. This novel regulatory mechanism provides a new perspective for the antitumor effect of apatinib beyond angiogenesis inhibition.

Whilst researches elucidating a diversity of intracellular mechanisms, platinum-resistant epithelial ovarian cancer (EOC) remains a major challenge in the treatment of ovarian cancer. Here we report that Exo70, a key subunit of the exocyst complex, contributes to both innate and acquired cisplatin resistance of EOC. Upregulation of Exo70 is observed in EOC tissues and is related to platinum resistance and progression-free survival of EOC patients. Exo70 suppressed the cisplatin sensitivity of EOC cells through promoting exocytosis-mediated efflux of cisplatin. Moreover, cisplatin-induced autophagy-lysosomal degradation of Exo70 protein by modulating phosphorylation of AMPK and mTOR, thereby reducing the cellular resistance. However, the function was hampered during prolonged cisplatin treatment, which in turn stabilized Exo70 to facilitate the acquired cisplatin resistance of EOC cells. Knockdown of Exo70, or inhibiting exocytosis by Exo70 inhibitor Endosidin2, reversed the cisplatin resistance of EOC cells both in vitro and in vivo. Our results suggest that Exo70 overexpression and excessive stability contribute to innate and acquired cisplatin resistance through the increase in cisplatin efflux, and targeting Exo70 might be an approach to overcome cisplatin resistance in EOC treatment.

Hyperactivated glucose uptake and glycolytic metabolism are considered as a hallmark of cancer. Berberine, a natural alkaloid with tumor‑selective anticancer effects, has been shown to promote glucose uptake in metabolic tissues and cells. However, whether and how berberine regulates the glucose metabolism of cancer cells are still poorly understood. In the present study, we revealed that berberine, which suppressed the growth of colon cancer cell lines HCT116 and KM12C, greatly inhibited the glucose uptake and the transcription of glucose metabolic genes, GLUT1, LDHA and HK2 in these two cell lines as assessed by RT‑qPCR. A mechanistic study further indicated that the protein expression but not mRNA transcription of HIF‑1α, a well‑known transcription factor critical for dysregulated cancer cell glucose metabolism, was dramatically inhibited in berberine‑treated colon cancer cell lines. Using western blot analysis, this regulation appears to occur via protein synthesis but not protein stability as blockade of HIF‑1α protein degradation by hypoxia mimic desferrioxamine (DFX) or proteasome inhibitor MG132 did not affect berberine's effect. In addition, mTOR signaling previously reported to regulate HIF‑1α protein synthesis was further found to be suppressed by berberine. Taken together, our results indicated that berberine inhibits overactive glucose metabolism of colon cancer cells via suppressing mTOR‑depended HIF‑1α protein synthesis, which provided not only a novel mechanism involved in berberine's tumor‑specific toxicity but also a theoretical basis for the development of berberine for colon cancer treatment.