Jian Liu

Targeting HK3 in tumor-associated macrophages enhances antitumor immunity through augmenting antigen cross-presentation in cervical cancer

Background Tumor-associated macrophages (TAMs) are among the most prevalent cells within the tumor microenvironment (TME) of cervical cancer (CC). Although TAMs frequently exhibit an immunosuppressive phenotype, their plasticity enables them as an intriguing reprogrammable target for immunotherapy of CC. Methods Consensus clustering was employed to delineate immune infiltration patterns in a cohort of 119 patients with CC. Single-cell RNA sequencing, complemented by flow cytometry analysis, was used to characterize hexokinase 3 (HK3)-expressing cell populations. In vivo tumor models were established to assess the functional impact of HK3-expressing cells on the TME, with interventions including Hk3 knockout and CD8+ T-cell depletion. A comprehensive approach involving bulk RNA sequencing, immunoprecipitation assays, confocal microscopy imaging, and in vitro co-culture systems was implemented to elucidate the mechanisms underlying HK3 inhibition-mediated enhancement of antitumor immunity. Furthermore, the therapeutic efficacy of HK3 inhibition, both as a monotherapy and in combination with immunotherapeutic strategies, was systematically evaluated in preclinical tumor models. Results We elucidated a cross-regulation between TAMs and CD8+ T cells, with HK3 serving as a central regulatory node. Upon HK3 expression was upregulated by CD8+ T cells through the IFN-γ-STAT1 signaling axis, TAMs exhibited impaired cross-presentation capacity, which in turn attenuated CD8+ T cell-mediated antitumor immunity. Mechanistically, HK3 physically interacted with mechanistic target of rapamycin (mTOR), promoting nuclear translocation of transcription factor EB (TFEB) and resulting in excessive lysosomal activation and antigen degradation. Moreover, targeting HK3 in combination with immune checkpoint blockade yielded a synergistic effect in enhancing antitumor immunity. Conclusions Targeting HK3 in TAMs represents a promising therapeutic strategy capable of enhancing antitumor immunity and synergizing with immune checkpoint blockade by restoring efficient antigen cross-presentation.

Constitutive expression of progesterone receptor isoforms promotes the development of hormone-dependent ovarian neoplasms

Altering the relative abundance of progesterone receptor isoforms drives ovarian neoplasia in mice.

A targetable MYBL2-ATAD2 axis governs cell proliferation in ovarian cancer

The chromatin-modifying enzyme ATAD2 confers oncogenic competence and proliferative advantage in malignances. We previously identified ATAD2 as a marker and driver of cell proliferation in ovarian cancer (OC); however, the mechanisms whereby ATAD2 is regulated and involved in cell proliferation are still unclear. Here, we disclose that ATAD2 displays a classical G2/M gene signature, functioning to facilitate mitotic progression. ATAD2 ablation caused mitotic arrest and decreased the ability of OC cells to pass through nocodazole-arrested mitosis. ChIP-seq data analyses demonstrated that DREAM and MYBL2-MuvB (MMB), two switchable MuvB-based complexes, bind the CHR elements in the ATAD2 promoter, representing a typical feature and principle mechanism of the periodic regulation of G2/M genes. As a downstream target of MYBL2, ATAD2 deletion significantly impaired MYBL2-driven cell proliferation. Intriguingly, ATAD2 silencing also fed back to destabilize the MYBL2 protein. The significant coexpression of MYBL2 and ATAD2 at both the bulk tissue and single-cell levels highlights the existence of the MYBL2-ATAD2 signaling in OC patients. This signaling is activated during tumorigenesis and correlated with TP53 mutation, and its hyperactivation was found especially in high-grade serous and drug-resistant OCs. Disrupting this signaling by CRISPR/Cas9-mediated ATAD2 ablation inhibited the in vivo growth of OC in a subcutaneous tumor xenograft mouse model, while pharmacologically targeting this signaling with an ATAD2 inhibitor demonstrated high therapeutic efficacy in both drug-sensitive and drug-resistant OC cells. Collectively, we identified a novel MYBL2-ATAD2 proliferative signaling axis and highlighted its potential application in developing new therapeutic strategies, especially for high-grade serous and drug-resistant OCs.

DHCR7 promotes lymph node metastasis in cervical cancer through cholesterol reprogramming-mediated activation of the KANK4/PI3K/AKT axis and VEGF-C secretion

Cervical cancer (CC) patients with lymph node metastasis (LNM) have a poor prognosis. However, the molecular mechanism of LNM in CC is unclear, and there is no effective clinical treatment. Here, we found that 7-dehydrocholesterol reductase (DHCR7), an enzyme that catalyzes the last step of cholesterol synthesis, was upregulated in CC and closely related to LNM. Gain-of-function and loss-of-function experiments proved that DHCR7 promoted the invasion ability of CC cells and lymphangiogenesis in vitro and induced LNM in vivo. The LNM-promoting effect of DHCR7 was partly mediated by upregulating KN motif and ankyrin repeat domains 4 (KANK4) expression and subsequently activating the PI3K/AKT signaling pathway. Alternatively, DHCR7 promoted the secretion of vascular endothelial growth factor-C (VEGF-C), and thereby lymphangiogenesis. Interestingly, cholesterol reprogramming was needed for the DHCR7-mediated promotion of activation of the KANK4/PI3K/AKT axis, VEGF-C secretion, and subsequent LNM. Importantly, treatment with the DHCR7 inhibitors AY9944 and tamoxifen (TAM) significantly inhibited LNM of CC, suggesting the clinical application potential of DHCR7 inhibitors in CC. Collectively, our results uncover a novel molecular mechanism of LNM in CC and identify DHCR7 as a new potential therapeutic target.