Boosting Cancer Immunotherapy via Reversing PD-L1-Mediated Immunosuppression with a Molecularly Imprinted Lysosomal Nanodegrader.

Immune checkpoint blockade therapy has achieved important clinical advances in several types of tumors, particularly via targeting the PD-1/PD-L1 axis. However, existing therapeutic strategies that suppress the PD-1/PD-L1 signal pathway usually experience low treatment efficacy and the risk of causing autoimmune diseases. Herein, we report a cancer cell-targeted molecularly imprinted lysosomal nanodegrader (MILND) for boosting immune checkpoint blockade therapy against tumors. The MILND, imprinted with the N-terminal epitope of PD-L1 as an imprinting template, could specifically target the PD-L1 on tumor cells to promote cellular uptake. This process further induces the transport of PD-L1 into lysosomes for degradation, ultimately resulting in the downregulation of PD-L1 expression levels on tumor cells. As a result, a T cell-mediated immune response in the body was activated via the blockade of the PD-1/PD-L1 signaling pathway, which triggered a durable antitumor efficacy. In vivo experiments demonstrated that the MILND could effectively accumulate in tumor sites and exhibit strong tumor growth suppression efficacy in a xenograft tumor model without obvious side effects. Therefore, the MILND provides not only a promising strategy for boosting cancer immunotherapy but also insights for developing molecular imprinting-empowered nanomedicines.

Immunotherapy of microsatellite stable colorectal cancer: resistance mechanisms and treatment strategies.

In recent years, immunotherapy strategies based on immune checkpoint inhibitors have yielded good efficacy in colorectal cancer (CRC)especially in colorectal cancer with microsatellite instability-high. However, microsatellite-stable (MSS) CRCs account for about 85% of CRCs and are resistant to immunotherapy. Previous studies have shown that compared with MSS CRC, high microsatellite instability CRC possesses a higher frequency of mutations and can generate more neoantigens. Therefore, improving the sensitivity of immunotherapy to MSS CRC is a hot topic which is crucial for the treatment of MSS CRC. This review aims to discuss the factors contributing to MSS CRC insensitivity to immunotherapy and explored potential solutions to overcome immunotherapy resistance.

Targeting key RNA methylation enzymes to improve the outcome of colorectal cancer chemotherapy (Review).

RNA methylation modifications are closely linked to tumor development, migration, invasion and responses to various therapies. Recent studies have shown notable advancements regarding the roles of RNA methylation in tumor immunotherapy, the tumor microenvironment and metabolic reprogramming. However, research on the association between tumor chemoresistance and N6­methyladenosine (m6A) methyltransferases in specific cancer types is still scarce. Colorectal cancer (CRC) is among the most common gastrointestinal cancers worldwide. Conventional chemotherapy remains the predominant treatment modality for CRC and chemotherapy resistance is the primary cause of treatment failure. The expression levels of m6A methyltransferases, including methyltransferase­like 3 (METTL3), METTL14 and METTL16, in CRC tissue samples are associated with patients' clinical outcomes and chemotherapy efficacy. Natural pharmaceutical ingredients, such as quercetin, have the potential to act as METTL3 inhibitors to combat chemotherapy resistance in patients with CRC. The present review discussed the various roles of different types of key RNA methylation enzymes in the development of CRC, focusing on the mechanisms associated with chemotherapy resistance. The progress in the development of certain inhibitors is also listed. The potential of using natural remedies to develop antitumor medications that target m6A methylation is also outlined.

Genomic landscape and efficacy of HER2-targeted therapy in patients with HER2-mutant non-small cell lung cancer.

Background: HER2-targeted therapy provides survival benefits to HER2-mutant non-small cell lung cancer (NSCLC). A better understanding of the clinical and genomic characterization of treatment-naïve HER2-positive NSCLC, as well as the efficacy of and resistance to HER2-targeted therapy in HER2-altered NSCLC, could promote further improvement of HER2 targeted therapy. Methods: HER2-altered NSCLC patients was retrospectively included and their genomic profiles were performed by next-generation sequencing. The clinical outcomes included overall response rate, disease control rate and progression-free survival. Results: Among 176 treatment-naïve patients with HER2 alterations, 64.8% harbored HER2 mutations with/without HER2 amplification, and 35.2% carried HER2 amplification only. Molecular characterization was correlated with tumor stage that late-stage NSCLC with HER2 oncogenic mutations showed a higher prevalence of TP53 mutations and a higher tumor mutation burden. However, this correlation was not found in patients with HER2 amplification only. Twenty-one patients with HER2 alterations treated with pyrotinib or afatinib were retrospectively enrolled. Pyrotinib yielded a longer median progression-free survival than afatinib (5.9 [95% CI, 3.8-13.0] vs. 4.0 months [95% CI, 1.9-6.3], P = 0.06) in these patients. Analysis of the genomic profiles before and after anti-HER2 targeted therapies identified de novo HER2 copy number gain and G518W mutation, as well as mutations involving DNA damage repair signaling, SWI-SNF complex, and epigenetic regulations as potential resistance mechanisms. Conclusion: HER2-mutant NSCLC had different molecular features from HER2-amplified NSCLC, and its genomic profile was dependent of tumor stage. Pyrotinib had superior therapeutic effects than afatinib in HER2-altered NSCLC, although larger cohorts are warranted to validate it. HER2-dependent and -independent resistance mechanisms to afatinib and pyrotinib were unveiled.

Machine learning-empowered cis-diol metabolic fingerprinting enables precise diagnosis of primary liver cancer.

Cis-diol metabolic reprogramming evolves during primary liver cancer (PLC) initiation and progression. However, owing to the low concentrations and highly structural heterogeneity of cis-diols in vivo, severe interference from complex biofluids and limited profiling coverage of existing methods, in-depth profiling of cis-diol metabolites and linking their specific changes with PLC remain challenging. Besides, due to the low specificity of widely used protein biomarkers, accurate classification of PLC from hepatitis still represents an unmet need in clinical diagnostics. Herein, to high-coverage profile cis-diols and explore the translational potential of them as biomarkers, a machine learning-empowered boronate affinity extraction-solvent evaporation assisted enrichment-mass spectrometry (MLE-BESE-MS) was developed. A single analytical platform integrated with multiple complementary functions, including pH-controlled boronate affinity extraction, solvent evaporation-assisted enrichment and nanoelectrospray ionization-based cis-diol identification, was constructed, which significantly improved the metabolite coverage. Meanwhile, by virtue of machine learning (principal components analysis, orthogonal partial least-squares discrimination analysis and random forest), collected cis-diols were statistically screened to extract efficient features for precise PLC diagnosis, and the results outperform the routinely used protein biomarker-based methods both in sensitivity (87.5% vs. less than 70%) and specificity (85.7% vs. ca. 80%). This machine learning-empowered integrated MS platform advanced the targeted metabolic analysis for early cancer diagnosis, rendering great promise for clinical translation.

Bioinformatic Analysis Identifies Potential Key Genes in the Pathogenesis of Melanoma.

Melanoma is the deadliest skin tumor and is prone to distant metastases. The incidence of melanoma has increased rapidly in the past few decades, and current trends indicate that this growth is continuing. This study was aimed to explore the molecular mechanisms of melanoma pathogenesis and discover underlying pathways and genes associated with melanoma. We used high-throughput expression data to study differential expression profiles of related genes in melanoma. The differentially expressed genes (DEGs) of melanoma in GSE15605, GSE46517, GSE7553, and the Cancer Genome Atlas (TCGA) datasets were analyzed. Differentially expressed genes (DEGs) were identified by paired t-test. Then the DEGs were performed cluster and principal component analyses and protein-protein interaction (PPI) network construction. After that, we analyzed the differential genes through bioinformatics and got hub genes. Finally, the expression of hub genes was confirmed in the TCGA databases and collected patient tissue samples. Total 144 up-regulated DEGs and 16 down-regulated DEGs were identified. A total of 17 gene ontology analysis (GO) terms and 11 pathways were closely related to melanoma. Pathway of pathways in cancer was enriched in 8 DEGs, such as junction plakoglobin (JUP) and epidermal growth factor receptor (EGFR). In the PPI networks, 9 hub genes were obtained, such as loricrin (LOR), filaggrin (FLG), keratin 5 (KRT5), corneodesmosin (CDSN), desmoglein 1 (DSG1), desmoglein 3 (DSG3), keratin 1 (KRT1), involucrin (IVL), and EGFR. The pathway of pathways in cancer and its enriched DEGs may play important roles in the process of melanoma. The hub genes of DEGs may become promising melanoma candidate genes. Five key genes FLG, DSG1, DSG3, IVL, and EGFR were identified in the TCGA database and melanoma tissues. The results suggested that FLG, DSG1, DSG3, IVL, and EGFR might play important roles and potentially be valuable in the prognosis and treatment of melanoma. These hub genes might well have clinical significance as diagnostic markers.

Landscape and Dynamics of Single Immune Cells in Hepatocellular Carcinoma.

The immune microenvironment of hepatocellular carcinoma (HCC) is poorly characterized. Combining two single-cell RNA sequencing technologies, we produced transcriptomes of CD45+ immune cells for HCC patients from five immune-relevant sites: tumor, adjacent liver, hepatic lymph node (LN), blood, and ascites. A cluster of LAMP3+ dendritic cells (DCs) appeared to be the mature form of conventional DCs and possessed the potential to migrate from tumors to LNs. LAMP3+ DCs also expressed diverse immune-relevant ligands and exhibited potential to regulate multiple subtypes of lymphocytes. Of the macrophages in tumors that exhibited distinct transcriptional states, tumor-associated macrophages (TAMs) were associated with poor prognosis, and we established the inflammatory role of SLC40A1 and GPNMB in these cells. Further, myeloid and lymphoid cells in ascites were predominantly linked to tumor and blood origins, respectively. The dynamic properties of diverse CD45+ cell types revealed by this study add new dimensions to the immune landscape of HCC.

Antitumor activity of SR splicing-factor 5 knockdown by downregulating pyruvate kinase M2 in non-small cell lung cancer cells.

SR splicing-factors (SRSFs) play a vital role in carcinogenesis. SRSF5 was demonstrated to be upregulated in lung cancer and identified as a novel prognostic indicator for small-cell lung cancer. However, the role of SRSF5 in the pathogenesis of non-small cell lung cancer (NSCLC) and the molecular mechanism involved are still undefined. The expression of SRSF5 in NSCLC cells was detected by quantitative real-time polymerase chain reaction and Western blot analysis. The proliferation of cells was evaluated by cell counting kit-8 and BrdU assays. Apoptosis was assessed by flow cytometry and Western blot analysis of apoptosis-associated proteins including B-cell lymphoma 2 (Bcl-2), Bax, and cytochrome C (Cyt C). Glycolysis was detected by determining glucose consumption, lactate production, and pyruvate kinase M2 (PKM2) expression. We found that SRSF5 messenger RNA and protein levels were elevated in NSCLC cells. SRSF5 knockdown inhibited the proliferation and Ki67 expression in NSCLC cells. SRSF5 silencing increased the apoptotic rate, upregulated Bax and Cyt C, and decreased Bcl-2 level in NSCLC cells. Moreover, Knockdown of SRSF5 repressed glycolysis in NSCLC cells via reducing PKM2 expression. Enhanced glycolysis by PKM2 overexpression attenuated the effects of SRSF5 silencing on NSCLC cell proliferation and apoptosis. Overall, knockdown of SRSF5 inhibited proliferative ability and induced apoptosis by suppressing PKM2 expression in NSCLC cells.

Knockdown of lncRNA PVT1 Inhibits Glioma Progression by Regulating miR-424 Expression.

Plasmacytoma variability translocation 1 (PVT1), an oncogene, has been reported to be highly expressed in many tumors, including human glioma, gastric cancer, and non-small cell lung cancer. Functionally, it could also regulate the development of tumor cells. However, its specific roles and pathogenesis in human gliomas are still not clear. This study investigated the function and mechanism of PVT1 knockdown in the proliferation and malignant transformation of human gliomas. We first examined the expression levels of PVT1 and miR-424 in human glioma tissues and cell lines. We also used gene manipulation techniques to explore the effects of PVT1 knockdown on cell viability, migration, invasion, and miR-424. We found that PVT1 knockdown effectively inhibited cell viability, migration, and invasion of human glioma cells and increased miR-424 expression. Based on the negative correlation between PVT1 and miR-424, we then confirmed the direct interaction between PVT1 and miR-424 using RNA immunoprecipitation (RIP) and luciferase reporter assays. Further, we established a xenograft nude mouse model to determine the role and mechanism of PVT1 on tumor growth in vivo. In addition, PVT1 knockdown was shown to promote miR-424 in vivo. In summary, the present study demonstrated that PVT1 knockdown could negatively regulate miR-424 to inhibit human glioma cell activity, migration, and invasiveness. PVT1 knockdown could negatively regulate miR-424 to inhibit cellular activity, migration, and invasiveness in human gliomas, which explained the oncogenic mechanism of PVT1 in human gliomas. It also suggested that PVT1 might be a novel therapeutic target for human gliomas.