Background: Long noncoding RNAs (lncRNAs) are emerging as critical regulatory elements and play fundamental roles in the biology of various cancers. However, we are still lack of knowledge about their expression patterns and functions in human colorectal cancer (CRC). Methods: Differentially expressed lncRNAs in CRC were identified by bioinformatics screen and the level of MIR22HG in CRC and control tissues were determined by qRT-PCR. Cell viability and migration capacities were examined by MTT and transwell assay. Mouse model was used to examine the function and rational immunotherapy of MIR22HG in vivo. Results: We systematically investigated the expression pattern of lncRNAs and revealed MIR22HG acts as a tumor suppressor in CRC. The expression of MIR22HG was significantly decreased in CRC, which was mainly driven by copy number deletion. Reduced expression of MIR22HG was significantly associated with poor overall survival. Silencing of MIR22HG promoted cell survival, proliferation and tumor metastasis in vitro and in vivo. Mechanistically, MIR22HG exerts its tumor suppressive activity by competitively interacting with SMAD2 and modulating the activity of TGFβ pathway. Decreased MIR22HG promoted the epithelial-mesenchymal transition in CRC. Importantly, we found that MIR22HG expression is significantly correlated with CD8A and overexpression of MIR22HG triggers T cell infiltration, enhancing the clinical benefits of immunotherapy. Conclusion: MIR22HG acts as a tumor suppressor in CRC. Our data provide mechanistic insights into the regulation of MIR22HG in TGFβ pathway and facilitates immunotherapy in cancer.
RNA-binding proteins (RBPs) play fundamental roles in cancer; however, we still lack knowledge about to what extent RBPs are dysregulated, as well as about perturbed signaling pathways in cancer. In this study, we integrated analysis of multidimensional data across >10,000 cancer patients and >1,000 cell lines. We identified a top candidate RBP: eukaryotic translation initiation factor 2 subunit beta (EIF2S2). EIF2S2 is highly expressed in tumors and is associated with malignant features as well as patient prognosis. Functional assays performed in cancer cells revealed that EIF2S2 promotes cancer cell proliferation, migration, and invasion in vitro as well as tumor growth and metastasis in vivo. Mechanistic investigations further demonstrated that EIF2S2 promotes tumorigenesis and progression by directly binding to a long non-coding RNA, LINC01600, which physically interacts with the MYC protein and increases its stability. Interestingly, we revealed that the EIF2S2-LINC01600-MYC axis can activate the Wnt/β-catenin pathway by inhibiting the activity of FHIT-related enhancers and FHIT expression. Finally, EIF2S2 knockdown combined with oxaliplatin treatment could be a potential combination therapy in cancer. Our integrated analysis provided detailed knowledge of the function of the EIF2S2-LINC01600-MYC axis, which will facilitate the development of rational combination therapies for cancer.
8 September 2022 in Journal of Experimental & Clinical Cancer Research
Background: Long noncoding RNAs (lncRNAs) are emerging as critical regulators of gene expression and play fundamental roles in various types of cancer. Current developments in transcriptome analyses unveiled the existence of lncRNAs; however, their functional characterization remains a challenge. Methods: A bioinformatics screen was performed by integration of multiple omics data in hepatocellular carcinoma (HCC) prioritizing a novel oncogenic lncRNA, LINC01132. Expression of LINC01132 in HCC and control tissues was validated by qRT-PCR. Cell viability and migration activity was examined by MTT and transwell assays. Finally, our results were confirmed in vivo mouse model and ex vivo patient derived tumor xenograft experiments to determine the mechanism of action and explore LINC01132-targeted immunotherapy. Results: Systematic investigation of lncRNAs genome-wide expression patterns revealed LINC01132 as an oncogene in HCC. LINC01132 is significantly overexpressed in tumor and associated with poor overall survival of HCC patients, which is mainly driven by copy number amplification. Functionally, LINC01132 overexpression promoted cell growth, proliferation, invasion and metastasis in vitro and in vivo. Mechanistically, LINC01132 acts as an oncogenic driver by physically interacting with NRF and enhancing the expression of DPP4. Notably, LINC01132 silencing triggers CD8+ T cells infiltration, and LINC01132 knockdown combined with anti-PDL1 treatment improves antitumor immunity, which may prove a new combination therapy in HCC. Conclusions: LINC01132 functions as an oncogenic driver that induces HCC development via the NRF1/DPP4 axis. Silencing LINC01132 may enhance the efficacy of anti-PDL1 immunotherapy in HCC patients.
Long noncoding RNAs (lncRNAs) have been shown to play crucial roles in human cancers. However, the underlying biological functions and mechanisms of lncRNAs in cholangiocarcinoma (CCA) remain largely unknown. We aimed to characterize the transcriptional landscape of lncRNAs in CCA and identify lncRNAs that were able to serve as prognosis markers and therapeutic targets for CCA. Here, we investigated the transcriptional landscape and dysregulation of lncRNAs in CCA. LINC01714 was found to be recurrently downregulated in CCA tumor samples. Our results revealed that decreased LINC01714 expression was associated with the poor survival of CCA patients. Our observations revealed that LINC01714 suppressed the proliferation, migration, and invasion abilities of CCA cells both in vitro and in vivo. Furthermore, we found that LINC01714 physically interacted with Forkhead Box O3 (FOXO3) and increased the FOXO3 protein level. In addition, LINC01714 could decrease the phosphorylation level of FOXO3. Interestingly, LINC01714 was able to enhance the sensitivity to gemcitabine in CCA tumor cells through modulating phosphorylated FOXO3-Ser318. Our study revealed LINC01714 as a promising prognostic indictor for patients with CCA, provided insights into the molecular pathogenesis of CCA, and also showed that LINC01714 is a potential therapeutic combination for gemcitabine in CCA treatment.
Colorectal cancer (CRC) is widely recognized as the third most prevalent malignancy globally and the second leading cause of cancer-related mortality. Traditional treatment modalities for CRC, including surgery, chemotherapy, and radiotherapy, can be utilized either individually or in combination. However, these treatments frequently result in significant side effects due to their non-specificity and cytotoxicity affecting all cells. Moreover, a considerable number of patients face relapses following these treatments. Consequently, it is imperative to explore more efficacious treatment interventions for CRC patients. Immunotherapy, an emerging frontier in oncology, represents a novel therapeutic approach that leverages the body's immune system to target cancer cells. The principal advantage of immunotherapy is its capacity to selectively target cancer cells while minimizing damage to healthy cells. Its recent adoption as a neoadjuvant therapy presents significant potential to transform the treatment landscape for both primary resectable and metastatic CRC. This review endeavors to offer a comprehensive overview of current strategies in CRC immunotherapy, critically analyze existing literature, underscore anticipated outcomes from ongoing clinical trials, and deliberate on the challenges and impediments encountered within the field of immunotherapy.
Bone is a common site for cancer metastasis, yet the mechanisms driving human spinal bone metastases (BMs) are poorly understood. Here, we obtained a single-cell RNA sequencing (scRNA-seq) atlas of 62 BMs across 13 different origins, along with paired primary tumor and normal bone marrow. Unsupervised clustering of cancer cell functional programs revealed 3 groups with distinct prognosis and tumor microenvironment. Integrative analysis with large-scale primary and metastatic pan-cancer and healthy bone marrow scRNA-seq datasets revealed SELE-positive endothelial cells, osteoblasts, and osteoclasts associated with cancer cell proliferation. We also identified BM-enriched exhausted CD8+ T cells with increased expression of immune checkpoint genes. In bone metastatic mouse models, a combined anti-PD-1/TIGIT immune therapy effectively suppressed tumor cell proliferation and significantly enhanced the cytotoxic activity of CD8+ T cells. Our results provide a systematic view of the molecular basis of BM and suggest future avenues for immunotherapy optimization for BM patients.