Journal of Experimental & Clinical Cancer Research最新文献

Background: Cellular senescence provides a protective barrier against tumorigenesis. However, the detailed mechanisms underlying tumor cells bypass senescence to malignant progression of non-small cell lung cancer (NSCLC) are still poorly understood.

Methods: In this study, we assessed the impact of KRT19 on NSCLC using xenograft tumor models, EdU, CCK8, colony formation and transwell assay. We performed chromatin immunoprecipitation sequencing and dual luciferase reporter assay to explore the mechanism through which H3K18 lactylation (H3K18la) mediated KRT19. The mechanism underlying KRT19 regulated p21-driven cellular senescence was explored by senescence-associated β-galactosidase staining, flow cytometry and further identified by RNA sequencing, mass spectrometry, immunofluorescence, co-immunoprecipitation and protein ubiquitination assay. The clinical significance of H3K18la/KRT19/p21 was determined by immunohistochemistry in human NSCLC specimens and bioinformatics analysis of TCGA database and Kaplan-Meier method. We evaluated the effects of KRT19 inhibition and anti-PD-1 on NSCLC growth and immune infiltration using xenograft tumor models, flow cytometry and CIBERSORT.

Results: Our study revealed that elevated expression of KRT19 was correlated with poor prognosis of NSCLC patients and exhibited oncogenic activity in NSCLC. Mechanistically, lactate-derived H3K18la activated the transcription of KRT19 via directly binding to its promoter. KRT19 blocked the transcriptional activation of p21 by p53, alternatively, KRT19 also interacted with MYH9 to facilitate ubiquitination of p21 at K16. More significantly, blockade of KRT19 potently enhanced the cytotoxic function of tumor-infiltrating CD8⁺ T cells and synergistically repressed NSCLC progression when combining with anti-PD-1.

Conclusion: Our study emphasizes the importance of lactylation-driven KRT19 for overriding senescence and promoting NSCLC progression, reinforcing the potential of combination therapy strategies with KRT19 inhibitors to yield favorable responses in patients with NSCLC.

Background: Recurrent/metastatic head and neck squamous cell carcinoma ((R/M) HNSCC) represents one of the most aggressive and immunosuppressive cancers. Despite the introduction of immune checkpoint inhibitors (ICIs), only a limited number of patients obtain long-term benefits. In (R/M) HNSCC patients, the antitumor immune response is defective, conferring resistance and promoting tumor progression. Therefore, the identification of novel biomarkers for superior clinical outcomes and easily accessible in standard clinical settings is still an unmet clinical need.

Methods: Blood liquid biopsies obtained from (R/M) HNSCC patients undergoing pembrolizumab therapy (monotherapy or in combination with chemotherapy) were analyzed by flow cytometry to evaluate the levels of circulating immunosuppressive regulatory T cells (Tregs) and myeloid derived suppressor cells (MDSCs), at baseline and during therapy. Correlations between these immunosuppressive immune cell subsets and clinical parameters (clinical response rate, progression-free survival (PFS), overall survival (OS) and performance status (PS)) were performed.

Results: Univariate analysis showed that before therapy, higher circulating levels of both CD137⁺Tregs and LOX-1⁺PMN-MDSCs, identified patients with significantly worse survival. Furthermore, CD137⁺Tregs resulted also positively correlated with worse PS, while high levels of LOX-1⁺PMN-MDSCs negatively affected response to pembrolizumab, with a significant increase in non-responsive patients during therapy. Interestingly, both CD137⁺Tregs as well as LOX-1⁺PMN-MDSCs exerted a higher immunosuppression on T cell proliferation than CD137^-Tregs and LOX-1⁻PMN-MDSCs, respectively. Multivariate analysis revealed that the circulating LOX-1⁺PMN-MDSC subset resulted as an independent prognostic factor for survival by multivariate analysis, as confirmed in an independent validation cohort.

Conclusions: The levels of blood circulating LOX-1⁺PMN-MDSCs may be proposed as non-invasive biomarkers to predict clinical outcomes of (R/M) HNSCC patients developing resistance to immunotherapy, improving patient selection and suggesting novel personalized therapies.

Background: The discovery of ferroptosis as a novel mechanism of cell death has opened the door to a new scenario in which it could be used to support current cancer therapy, particularly in cases of relapse. Several compounds have been developed aimed to inhibit or induce ferroptosis in cancer cells by acting on different signaling pathways caable of activating or repressing, respectively, this cell death mechanism.

Main body: This review shows how treatmenting cancer cells with ferroptosis inducers results in improved efficacy of immunotherapy. Indeed, the advantage of affecting ferroptosis lies in the capacity of compounds to improve immune system compartments. The involvement of ferroptosis in cancer treatment is now emerging, demonstrating the high translational potential of this approach capable of carrying out an immune response against tumors, dendritic cells (DC), regulatory T cells (Treg), Natural Killer cells (NK) and tumor-associated macrophages (TAM) exert an interesting role. Some immune check-point inhibitors (ICIs) have been approved as cancer immunotherapy, because they target cytotoxic T lymphocyte-associated antigen 4 (CTLA4), programmed cell death protein 1 (PD-1) and its ligand PD-L1. For this reason, promising results have been achieved by combining ferroptosis inducers with ICIs. At the same time, combining Chimeric Antigen Receptor (CAR) T-cell therapy with ferroptosis inducers shows promising anti-tumor activity, particularly in solid tumors. This approach demonstrates how the modulation of ferroptosis may improve the efficacy of CAR T-cells treatment by promoting tumor cell death and enhancing immunogenicity.

Conclusion: In conclusion the development of clinical trials aimed at testing the efficacy of ferroptosis induction in combination with current cancer therapy will be the definitive proof of the valid opportunity provided by this therapeutic approach.

Background: Hepatocellular carcinoma (HCC) is the fifth leading cause of cancer-related mortality globally. Long non-coding RNAs (lncRNAs) are increasingly recognized for their pivotal roles in hepatocarcinogenesis. Specifically, the lncRNA LL22NC03-N14H11.1 (hereafter referred to as LL22NC03) has been characterized as a potent oncogenic factor in certain cancers. Therefore, our research aimed to investigate the involvement of LL22NC03 in HCC progression.

Methods: We analyzed the expression of IGF2BP3 in HCC specimens obtained from The Cancer Genome Atlas (TCGA) dataset. Further investigation via RNA pull-down and mass spectrometry analysis identified LL22NC03 as a binding partner of IGF2BP3, with LL22NC03 enhancing the stability of IGF2BP3 by inhibiting TRIM25-mediated ubiquitination. Subsequent in vitro and in vivo experiments were conducted to explore the modulation of LL22NC03 expression, in combination with manipulation of IGF2BP3 levels, which significantly impacted glycolysis, proliferation, migration, and invasiveness of HCC cells.

Results: The study identified LL22NC03 as a promoter of HCC proliferation and migration of HCC cells. LL22NC03 was observed to bind to the ubiquitination site of IGF2BP3, thereby preventing its degradation and enhancing its stability. This interaction ultimately inhibited the degradation of IGF2BP3. Additionally, the interaction between LL22NC03 and IGF2BP3 facilitated the transcription of MYC, leading to the upregulation of glycolytic genes, including HK2, LDHA, GLUT1, PKM2, and PDK1. Finally, IGF2BP3 played a role in stabilizing MYC by recognizing N6-methyladenosine (m6A) modifications.

Conclusion: The LL22NC03-IGF2BP3-MYC regulatory axis is critically involved in the progression of HCC, suggesting its potential as a novel therapeutic target for this malignancy.

Background: Colorectal liver metastasis (CRLM) occurs frequently in patients with colorectal cancer (CRC). Methionine adenosyltransferase (MAT) catalyzes the formation of S-adenosylmethionine, the principal methyl donor. MAT1A (encodes MATα1) is expressed mainly in normal adult liver, whereas MAT2A (encodes MATα2) is expressed in all extrahepatic tissues. MAT1A is a major defense against CRLM as loss of Mat1a sensitizes the liver to CRLM. In contrast, MAT2A is overexpressed in CRC and promotes oncogenicity. Here, we sought to determine if CRCs secrete MATα2 and if this influences CRLM.

Methods: Our study included human hepatocytes, human CRC cells, extracellular vesicle (EV) isolation, chromatin immunoprecipitation (ChIP), ChIP-seq, promoter activity assays, proliferation, migration, and invasion assays, western blotting, immunohistochemistry and immunofluorescence. We confirmed some of the findings using human hepatocyte spheroids, CRLM and normal liver tissue array, and plasma samples.

Results: CRCs secrete MATα2 in free but truncated form (MATα2-t) and intact within EVs (EV-MATα2). EV-MATα2 can be internalized by human hepatocytes and CRCs, found within the nucleus, which then binds to MAT1A and MAT2A promoters on ChIP to lower and increase MAT1A and MAT2A promoter activities, respectively. In human CRLM samples, hepatocytes in nontumor regions express lower MATα1 but higher MATα2 as compared to normal liver. Treating RKO cells with EVs released from RKO cells overexpressing MAT2A promoted cell proliferation, migration, and invasion. MATα2-t was detected at a higher level in media from colon, pancreatic, and prostate cancer cell lines than corresponding normal epithelial cells as well as in the plasma of CRC patients as compared to healthy controls. RKO cells treated with MATα2-t activated focal adhesion kinase (FAK), an important kinase for cancer cell evasion of apoptosis. Conversely, treatment with MATα2 neutralizing antibody inhibited FAK and induced apoptosis.

Conclusions: CRC cells secrete both MATα2 within EVs and free MATα2-t. EV-MATα2 can be internalized and act as a transcription factor to lower hepatocytes' MAT1A, the major defense against CRLM, while promoting CRC oncogenicity. Freely released MATα2-t acts as a ligand in an autocrine fashion to activate FAK, which is essential for CRC survival. Taken together, secreted MATα2 plays an essential role in promoting CRLM.

Background: Prostate cancer (PCa) is a globally prevalent malignancy in males and is imposing an increasing epidemiological burden. The androgen receptor (AR) signalling axis is fundamentally implicated in PCa tumorigenesis and disease progression. Although androgen deprivation therapy (ADT) elicits transient therapeutic responses in the majority of cases, progression to castration-resistant prostate cancer (CRPC) remains an almost universal clinical trajectory. Dysregulated lipid homeostasis, manifesting as intracellular lipid deposition, has been mechanistically linked to CRPC pathogenesis and therapeutic failure under enzalutamide regimens. However, effective strategies to mitigate lipid accumulation in PCa remain elusive.

Methods: STARD4, a key gene involved in lipid metabolism, was identified as functionally significant in PCa through integrated bioinformatics analysis of public databases. RT‒qPCR, western blot analysis, and IHC staining were performed to evaluate STARD4 expression, while Kaplan-Meier survival analysis, Gleason score, and tumor stage were performed to assess its clinical significance in PCa. The biological functions of STARD4 and its contribution to enzalutamide resistance were elucidated through in vitro and in vivo experiments. The effect of STARD4 on abnormal lipid accumulation in PCa cells was evaluated by Oil Red O (ORO) staining, while its impact on endoplasmic reticulum (ER) stress was assessed through ER-tracking imaging and transmission electron microscopy (TEM). Mechanistic exploration involves a combination of techniques, including RNA-seq analysis, Gene ontology analysis, coimmunoprecipitation (Co-IP), and GST pull-down assay, to analyse the interactions and potential mechanisms involving STARD4, AR, and E3 ubiquitin ligase UBE4B.

Results: In this study, we observed that STARD4 expression was markedly reduced in PCa tissues and was correlated with an adverse prognosis. STARD4 overexpression inhibited PCa cell proliferation, migration, and lipid accumulation while promoting apoptosis through ER stress. Mechanistically, STARD4 enhanced the interaction between UBE4B and AR, facilitating AR ubiquitination and degradation and thus suppressing AR signalling. Additionally, the upregulation of STARD4 expression enhanced sensitivity to enzalutamide in resistant cells by diminishing lipid accumulation and inhibiting the AR signalling pathway. In summary, STARD4 functions as a tumour suppressor in PCa by regulating cholesterol metabolism and modulating AR signalling.

Conclusions: Our findings identify STARD4 as a promising therapeutic target for reversing enzalutamide resistance in PCa while also providing novel insights for future research on lipid metabolism within the tumour microenvironment.

Background: The transcription factor Yin Yang 1 (YY1) and the Raf kinase inhibitory protein (RKIP) represent two molecular entities with diametrically opposed roles in cancer biology. They are key modulators of multiple cellular processes, including apoptosis, metastasis, and cell survival. YY1 functions predominantly as an oncogenic driver, promoting tumorigenesis, epithelial-mesenchymal transition (EMT), immune evasion, and resistance to chemo-immuno-therapy. In contrast, RKIP acts as a metastasis suppressor and chemo-immuno-sensitizer, inhibiting critical oncogenic signaling pathways. The inverse correlation between high YY1 and low RKIP expressions has been observed across various malignancies (such as prostate cancer, melanoma, colorectal cancer, cervical cancer, hematologic malignancies, etc.), suggesting a tightly regulated molecular axis influencing tumor progression and therapeutic response. This review systematically examines the contrasting roles of YY1 and RKIP in cancer pathogenesis (e.g. cell proliferation and cell cycle, angiogenesis, immune cells infiltration and immunosuppressive TME, check point inhibitors, resistance to apoptosis, cell energetics, etc.). Based on their opposing activities, we propose the term YYR-the YY1-RKIP regulatory network- to explain the interplay. YYR captures the bidirectional and context-dependent nature of their relationship for understanding transcriptional programming, immune suppression, tumor aggressiveness, and therapeutic resistance in cancer.

Conclusion: Understanding the dynamics of the YYR axis may offer new insights into prognostic markers and therapeutic strategies aimed at restoring tumor suppressor function and overcoming treatment resistance. Accordingly, we explore potential therapeutic strategies aimed at targeting YYR.