Targeting VCP potentiates immune checkpoint therapy for colorectal cancer

VCP Promotes Cholangiocarcinoma Development by Mediating BAP1 Ubiquitination-Dependent Degradation

Cholangiocarcinoma (CCA), recognized for its high malignancy, has been an enormous challenge due to lacking effective treatment therapy over the past decades. Recently, the targeted therapies, such as Pemigatinib and Ivosidenib, have provided new treatment options for patients carrying fibroblast growth factor receptor (FGFR) and isocitrate dehydrogenase 1/2 (IDH1/2) mutations, but only ~30% of patients harbor these mutants; it is urgent to explore novel targets and therapeutic therapies. The frequent downregulation of BAP1 has been observed in CCA, and the low expression of BAP1 is closely related to the poor prognosis of CCA. However, there are no effective interventions to re-activate BAP1 protein; blocking its degradation may provide a feasible strategy for BAP1-downregulation CCA treatment. In this study, we demonstrated the tumor-suppressive roles of BAP1 in CCA and identified VCP functions as the key upstream regulator mediated by BAP1 protein homeostasis. Mechanistically, VCP binds to BAP1 and promotes the latter's ubiquitination degradation via the ubiquitin-proteasome pathway, thus promoting cell proliferation and inhibiting cell apoptosis. Moreover, we found that VCP inhibitors inhibited CCA cell growth and promoted cell apoptosis by blocking BAP1 ubiquitination degradation. Collectively, our findings not only provided a novel mechanism underlying the aberrant low expression of BAP1 in CCA but also verified the anti-tumor effect of VCP inhibitors in CCA, offering a novel therapeutic target for CCA treatment.

Investigating the PI3K/AKT/mTOR axis in Buzhong Yiqi Decoction's anti-colorectal cancer activity

Buzhong Yiqi Decoction (BZYQD) is a traditional Chinese medicine renowned for its anti-colorectal cancer (CRC) properties. However, the bioactive components and mechanisms of BZYQD against CRC remain unknown. In this study, LC-MS was used to analyze the chemical composition of BZYQD. Next, the network pharmacology and molecular docking was used to investigate the core components and targets of BZYQD against CRC. Finally, we experimentally validated the potential mechanism of BZYQD against CRC through in vitro studies. Our results identified 26 chemical components in the BZYQD; 75 "hithubs" targets were screened by network pharmacology, and mainly involving pathways such as including pathways in cancer, P13K-Akt signaling pathway, proteoglycans in cancer, kaposi sarcoma-associated herpesvirus, and lipid and atherosclerosis signaling pathways. Based on the number of "hithubs" targets in the key pathways, the two most critical targets including AKT1 and PIK3CA were selected. The component-target network results indicated that astragaloside IV, gancaonin A, quercetin, poricoic acid A, and licoisoflavanone are key anti-CRC components in BZYQD. Molecular docking showed a strong binding affinity between these components and targets. The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway emerged as the primary target of BZYQD. Further in vitro studies confirmed that BZYQD's anti-CRC activity is mediated through the PI3K/AKT/mTOR axis and influences macrophage polarization. BZYQD exerts its therapeutic effects on CRC through multiple components, targets, and pathways. Our study elucidates the effective components and molecular mechanisms of BZYQD in CRC treatment and provides preliminary validation through molecular docking and experimental studies.

VCP downstream metabolite glycerol-3-phosphate (G3P) inhibits CD8+T cells function in the HCC microenvironment

CD8+T cells within the tumor microenvironment (TME) are often functionally impaired, which limits their ability to mount effective anti-tumor responses. However, the molecular mechanisms behind this dysfunction remain incompletely understood. Here, we identified valosin-containing protein (VCP) as a key regulator of CD8+T cells suppression in hepatocellular carcinoma (HCC). Our findings reveal that VCP suppresses the activation, expansion, and cytotoxic capacity of CD8+T cells both in vitro and in vivo, significantly contributing to the immunosuppressive nature of the TME. Mechanistically, VCP stabilizes the expression of glycerol-3-phosphate dehydrogenase 1-like protein (GPD1L), leading to the accumulation of glycerol-3-phosphate (G3P), a downstream metabolite of GPD1L. The accumulated G3P diffuses into the TME and directly interacts with SRC-family tyrosine kinase LCK, a critical component of the T-cell receptor (TCR) signaling pathway in CD8+T cells. This interaction heightens the phosphorylation of Tyr505, a key inhibitory residue, ultimately reducing LCK activity and impairing downstream TCR signaling. Consequently, CD8+T cells lose their functional capacity, diminishing their ability to fight against HCC. Importantly, we demonstrated that targeting VCP in combination with anti-PD1 therapy significantly suppresses HCC tumor growth and restores the anti-tumor function of CD8+T cells, suggesting synergistic therapeutic potential. These findings highlight a previously unrecognized mechanism involving VCP and G3P in suppressing T-cell-mediated immunity in the TME, positioning VCP as a promising upstream target for enhancing immunotherapy in HCC.

Akt enhances the vulnerability of cancer cells to VCP/p97 inhibition-mediated paraptosis

Valosin-containing protein (VCP)/p97, an AAA+ ATPase critical for maintaining proteostasis, emerges as a promising target for cancer therapy. This study reveals that targeting VCP selectively eliminates breast cancer cells while sparing non-transformed cells by inducing paraptosis, a non-apoptotic cell death mechanism characterized by endoplasmic reticulum and mitochondria dilation. Intriguingly, oncogenic HRas sensitizes non-transformed cells to VCP inhibition-mediated paraptosis. The susceptibility of cancer cells to VCP inhibition is attributed to the non-attenuation and recovery of protein synthesis under proteotoxic stress. Mechanistically, mTORC2/Akt activation and eIF3d-dependent translation contribute to translational rebound and amplification of proteotoxic stress. Furthermore, the ATF4/DDIT4 axis augments VCP inhibition-mediated paraptosis by activating Akt. Given that hyperactive Akt counteracts chemotherapeutic-induced apoptosis, VCP inhibition presents a promising therapeutic avenue to exploit Akt-associated vulnerabilities in cancer cells by triggering paraptosis while safeguarding normal cells.