Cellular Oncology最新文献

Purpose: High programmed death-ligand 1 (PD-L1) expression is associated with unfavorable clinical outcomes in epidermal growth factor receptor (EGFR)-mutated lung adenocarcinomas (LUAD) patients treated with tyrosine kinase inhibitors (TKIs) or anti-PD-1/PD-L1 therapy, yet the underlying mechanisms are less explored.

Methods: Bulk RNA sequencing (RNA-seq) datasets were analyzed to investigate intertumoral transcriptional variations linked to PD-L1 expression. Immunohistochemistry (IHC) was utilized to quantify PD-L1 expression on tumor cells. Digital spatial profiling (DSP) was performed on 23 EGFR-mutated LUAD tissue samples to characterize transcriptomic differences in tumor cell (TC), immune cell (IM), and macrophage (MA) compartments between PD-L1 high and low groups. Furthermore, a publicly available DSP dataset was analyzed and IHC was conducted for validation.

Results: Analysis of RNA-seq datasets identified differentially expressed genes, signaling pathways, and immune profiles associated with PD-L1 expression. Compared to low PD-L1 tumors, high PD-L1 tumors exhibited increased infiltration of T regulatory cells (Tregs) and enhanced immunosuppressive signatures. DSP analysis revealed compartment-specific molecular disparities: TC segment in high PD-L1 tumors showed upregulated signatures of cell proliferation, invasion, and metastasis. IM segment displayed increased infiltration of immunosuppressive cells, including Tregs and myeloid-derived suppressor cells and upregulated expression of inhibitory immunomodulators CD276, HAVCR2, and LGALS9C.

Conclusion: Combining bulk and spatial RNA-seq, this study characterized the molecular and immunological hallmarks of EGFR-mutated LUAD in the context of PD-L1 expression, providing new insights into the development of tailored therapeutic strategies for EGFR-mutated LUAD with high PD-L1 expression.

Purpose: Ferroptosis is a novel form of iron-dependent programmed cell death that is associated with the progression of various tumors and cancer treatment responses. However, its role in the clinical treatment of lung cancer, particularly in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), remains poorly understood. This study aims to explore the prognostic value of ferroptosis-related genes in lung cancer and establish a reliable predictive model.

Methods: We collected the GSE4573, TCGA-LUAD, and TCGA-LUSC datasets, comprising a total of 1,271 samples and a ferroptosis gene set of 717 genes. Weighted gene coexpression network analysis (WGCNA) was used to identify ferroptosis-related markers, followed by the application of 101 machine learning algorithms combining 10 different approaches to develop a ferroptosis-related signature (FRS) for lung cancer prognosis.

Results: The FRS demonstrated superior performance in predicting the survival of lung cancer patients, significantly outperforming traditional TNM and American Joint Committee on Cancer (AJCC) staging systems. External validation using the GSE13213 dataset also confirmed its robustness. Furthermore, the low-risk group exhibited higher immune microenvironment scores, suggesting a more active anti-tumor immune response, while the high-risk group showed elevated cell proliferation, migration, T-cell exclusion, and TIDE scores, indicating a more aggressive tumor phenotype. Additionally, the low-risk group demonstrated higher sensitivity to multiple drugs, including cisplatin, cyclophosphamide, paclitaxel, erlotinib, Niraparib, Rapamycin, Fulvestrant, and Venetoclax, highlighting its potential for guiding personalized treatment strategies.

Conclusion: The FRS represents a powerful and clinically relevant tool for predicting the survival of lung cancer patients, offering new insights into personalized treatment and therapeutic decision-making.

Background: Metastatic colorectal cancer (mCRC) remains a major cause of cancer-related mortality, but few noninvasive biomarkers exist to track disease progression or inform treatment strategies. Circulating tumor cells (CTCs) offer a minimally invasive source of tumor material, yet the prognostic significance of their genomic diversity remains unclear.

Methods: We conducted whole-exome sequencing of CTC pools from 29 mCRC patients to characterize their mutational landscape and assess associations with overall survival.

Results: Our analysis revealed substantial variation in mutational burden among patients, with all CTC pools harboring non-silent mutations in key CRC driver genes. Higher genomic diversity in CTC pools was significantly associated with reduced overall survival. Additionally, non-silent mutations in BCL9L emerged as a strong predictor of patient survival.

Conclusion: Genomic diversity and BCL9L mutational status in CTC pools emerged as strong predictors of survival in mCRC, underscoring the potential of CTC genomic profiling as a minimally invasive and clinically relevant prognostic tool in mCRC.

Purpose: Colorectal cancer (CRC) remains a major global health challenge, necessitating novel therapeutic approaches. β-carboline alkaloids, natural compounds with anticancer properties, have shown potential to inhibit cancer cell viability. Here, we synthesized β-carboline derivatives and explored their potential as CRC inhibitors.

Methods: The IC₅₀ values of β-carboline derivatives were determined by cell viability assay. The biological effects of the leading candidate were evaluated via cell cycle analysis, proliferation assay, colony formation, apoptosis assay, and reactive oxygen species detection. Mechanistic studies were performed using transcriptomic and proteomic analysis, validated by immunoblotting, pulldown assay, cycloheximide-chasing assay, and co-immunoprecipitation. An in vivo CRC xenograft model was used to assess the efficacy of the leading candidate.

Results: Z-7 was identified as the leading candidate due to its ability to induce apoptosis and cell cycle arrest in CRC cells. Transcriptomic and proteomic data revealed that Z-7 activated the p53 signaling pathway in p53 wild-type CRC by binding to MDM2 at the RING domain, and inhibiting the E3 ligase activity of MDM2, leading to the reduction of p53 ubiquitination. In vivo study showed Z-7 treatment elevated p53 expression and significantly suppressed tumor growth in xenograft models.

Conclusion: Z-7 is a promising candidate for CRC therapy, particularly in patients with functional p53 and elevated MDM2, warranting further clinical evaluation.

Background: Hepatocellular carcinoma (HCC) remains a therapeutic challenge due to limited treatment options and frequent resistance to targeted therapies. MET amplification is a promising therapeutic target in a subset of HCC. However, mechanisms of resistance to MET inhibitors are not fully understood, impeding the efficacy of treatments.

Methods: We performed a genome-wide CRISPR-Cas9 screen to identify genetic determinants of resistance to MET inhibitors. The efficacy of selective MET inhibitors, including capmatinib and tepotinib, was evaluated in MET-amplified HCC models. Mechanistic studies were conducted to characterize AKT signaling dynamics and tumour cell responses under various treatment conditions.

Results: MET inhibitors selectively suppressed tumour growth in MET-amplified HCC. However, PTEN deficiency sustained AKT activation despite MET blockade, facilitating tumour survival. Moreover, MET inhibitor treatment triggered adaptive upregulation of ERBB2/ERBB3, leading to AKT reactivation and resistance. Combined inhibition of MET and AKT or ERBB kinases synergistically restored therapeutic response and induced apoptosis. These resistance mechanisms also reduced the efficacy of cabozantinib. Notably, neither combination was effective in MET-high non-amplified HCC.

Conclusion: Our study identifies PTEN deficiency and ERBB2/ERBB3-mediated reactivation as key resistance mechanisms to MET inhibition in MET-amplified HCC. The findings support biomarker-informed combination strategies and underscore the importance of stratifying patients based on MET amplification status.

Purpose: Interferon gamma (IFNG) directly affects the antitumor immune response. ST6-β-galactoside α-2,6-sialyltransferase 1 (ST6GAL1) is also positively correlated with poor prognosis for colorectal cancer (CRC). we performed some works to exploreexplored the underlying mechanism to further understand immune escape in colorectal cancer (CRC).

Methods: First, we used clinical samples to confirm the relationship between ST6GAL1 and CRC. Afterward, we constructed overexpression/knockdown cell lines and performed bulk RNA sequencing, kinase phosphorylation chip, mass spectrometry, and in vitro and in vivo assays to explore the mechanism regulated by ST6GAL1. Finally, we verified the mechanism by performing immunoprecipitation and immunofluorescence (IF) staining.

Results: ST6-β-galactoside α-2,6-sialyltransferase 1 (ST6GAL1) expression was negatively correlated with the response to neoadjuvant chemotherapy in patients with CRC and negatively correlated with the sensitivity to IFNG in CRC cell lines. We confirmed that ST6GAL1 overexpression inhibited the infiltration of effector T cells, the levels of IFNG produced by CD8⁺ T cells and CD4⁺ T cells decreased, and the levels of granzyme B produced by effector cells decreased in animal models. The results of in vitro assays and phosphorylation chip detection revealed that ST6GAL1 inhibited IFNG receptor 1 (IFNGR1) phosphorylation, thus decreasing the activation of the JAK1/STAT1 signaling pathway. Through immunoprecipitation assays and mass spectrometry, we found that ST6GAL1 can sialylate BICD cargo adaptor 2 (BICD2), thereby affecting the interaction between BICD2 and IFNGR1 to ultimately inhibit the phosphorylation of IFNGR1 and promote immune escape.

Conclusions: Our results confirmed that ST6GAL1 decreases the sensitivity of tumor cells to IFNG. This study describes a novel mechanism by which ST6GAL1 promotes the immune escape and malignant progression of CRC.