Regulation Of Cancer Progression Research Articles

Mechanisms of TREM2 mediated immunosuppression and regulation of cancer progression.

Cancer immunotherapy has recently emerged as a key strategy for cancer treatment. TREM2, a key target for regulating the tumor immune microenvironment, is important in cancer treatment and progression. TREM2 is an immune signaling hub that regulates multiple pathological pathways. It not only suppresses anti-tumor immune responses by inhibiting T cell-mediated immune responses, but it also influences tumorigenesis by affecting NK cell-mediated anti-tumor immunity. Noticeably, TREM2 expression levels also vary significantly among different tumor cells, and it can regulate tumor progression by modulating various signaling pathways. Above all, by summarizing the role of TREM2 in cancer immunotherapy and the mechanism by which TREM2 regulates tumor progression, this paper clarifies TREM2's role in both tumor progression and cancer therapy, identifying a new therapeutic target for oncology diseases.

Elucidating the role of EPPK1 in lung adenocarcinoma development

BackgroundWe recently found that epiplakin 1 (EPPK1) alterations were present in 12% of lung adenocarcinoma (LUAD) cases and were associated with a poor prognosis in early-stage LUAD when combined with other molecular alterations. This study aimed to identify a probable crucial role for EPPK1 in cancer development.MethodsEPPK1 mRNA and protein expression was analyzed with clinical variables. Normal bronchial epithelial cell lines were exposed to cigarette smoke for 16 weeks to determine whether EPPK1 protein expression was altered after exposure. Further, we used CRISPR-Cas9 to knock out (KO) EPPK1 in LUAD cell lines and observed how the cancer cells were altered functionally and genetically.ResultsEPPK1 protein expression was associated with smoking and poor prognosis in early-stage LUAD. Moreover, a consequential mesenchymal-to-epithelial transition was observed, subsequently resulting in diminished cell proliferation and invasion after EPPK1 KO. RNA sequencing revealed that EPPK1 KO induced downregulation of 11 oncogenes, 75 anti-apoptosis, and 22 angiogenesis genes while upregulating 8 tumor suppressors and 12 anti-cell growth genes. We also observed the downregulation of MYC and upregulation of p53 expression at both protein and RNA levels following EPPK1 KO. Gene ontology enrichment analysis of molecular functions highlighted the correlation of EPPK1 with the regulation of mesenchymal cell proliferation, mesenchymal differentiation, angiogenesis, and cell growth after EPPK1 KO.ConclusionsOur data suggest that EPPK1 is linked to smoking, epithelial to mesenchymal transition, and the regulation of cancer progression, indicating its potential as a therapeutic target for LUAD.

PROGNOSTIC SIGNIFICANCE OF SOCS IN REGULATING CANCER PROGRESSION

Suppressor of cytokine signalling (SOCS) proteins have emerged as crucial regulators in cancer progression, exhibiting significant prognostic implications. This review explores the prognostic significance of SOCS in various cancer types and their role in modulating key signalling pathways involved in tumour growth, metastasis, and immune evasion. Understanding the intricate interplay between SOCS proteins and cancer progression provides valuable insights into developing targeted therapies and prognostic markers for improved patient management and outcomes. SOCS proteins are pivotal regulators of immune responses and inflammation, but their dysregulation has been implicated in cancer development and progression. We explore the mechanisms by which SOCS proteins exert their effects on oncogenic signalling pathways, such as JAK/STAT, PI3K/AKT, and MAPK pathways, highlighting their potential as therapeutic targets. Furthermore, understanding the complex interplay between SOCS proteins and cancer holds promise for the development of novel therapeutic strategies and precision medicine approaches tailored to individual patients.

The effect of ginger extract on expression of Gli1 and Patched-1 genes involved in breast cancer signaling pathway under in vitro condition

Introduction and Aim: Breast cancer ranks among the leading causes of death in women worldwide. Ginger has shown potential efficacy against certain cancer types, surpassing conventional therapies such as chemotherapy and radiation. However, its molecular mechanisms remain less understood. Materials and Methods: In this study, MCF-7 cancer cells were cultured and treated with various concentrations of aqueous ginger extract (20, 30, 45, 65 microgram/mL) for 12, 48, and 72 hours. The effects were assessed through gene expression analysis and cell vitality assays (MTT). Results: The cell vitality test revealed a direct correlation between cytotoxicity and extract concentration. Concentrations exceeding 30 microgram/mL exhibited significant cell death (IC50 of 104.03 microgram/mL). Gene expression analysis demonstrated an increase in Patched-1 and a decrease in Gli1 expression with rising extract concentrations. The maximum Patched-1 expression occurred at 65 microgram/mL after 72 hours. Patched-1 (oncogene) and Gli1 (tumor suppressor) are pivotal genes in the hedgehog (Hh) signalling pathway associated with breast cancer. Conclusion: It appears that ginger compounds play a substantial role in regulating cancer progression by influencing key components of the hedgehog signalling pathway.

Abstract 4265: ZEB1-regulated hyaluronan network in the lung tumor microenvironment

Abstract In the tumor microenvironment, hyaluronan surrounds neighboring cells as one of the major components of the extracellular matrix and stimulates the epithelial-mesenchymal transition (EMT) of various epithelial cancer cells. However, the mechanism of how the hyaluronic network is formed by cancer cells and regulates cancer progression and metastasis has not been known in detail. Therefore, we investigated the role of the hyaluronan network built-up by cancer cells in regulating cancer progression and metastasis in the tumor microenvironment. Our study demonstrated that ZEB1, an EMT-inducing transcription factor, reconstructs the hyaluronan network to induce the expression of ITIH2, a hyaluronan-binding protein, and hyaluronic acid synthase-2 (HAS2), ZEB1 was also shown to control the isoform switching of CD44, a hyaluronan receptor. ITIH2 knockdown and HAS inhibition reduced the formation of hyaluronan cables and inhibited cancer cell migration and invasion. In addition, the treatment of a specific ITIH2 inhibitor identified through deep learning-based screening suppressed the formation of hyaluronan cables, cell migration, and metastasis. These findings suggest that targeting the hyaluronan network could be a novel strategy for suppressing lung cancer progression and metastasis in the tumor microenvironment. Citation Format: Sieun Lee, Jihye Park, Eun Ju Kim, Seongran Cho, Sungsoo Park, Jonathan M Kurie, Young-Ho Ahn. ZEB1-regulated hyaluronan network in the lung tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4265.

Abstract 7075: Global epitranscriptomic and transcriptomic footprint revealed upregulation of methylated single minded 2-small variant (meSIM2-SV) in colorectal cancer (CRC) by NTMT1(METTL11A) via m6A-YTHDF1-dependent manner

Abstract Establishing global footprint of altered m6A mRNA is a unique method to identify the new prognostics biomarkers. Altered N6-methyladenosine(m6A) RNA methylation regulates cancer progression with uncharacterized mechanism. Here, we present novel link between m6A modification on 5’-UTR SIM2-SV contribution in colorectal cancer progression. MeRIP and RNA-seq data from 68 fresh frozen CRC samples revealed 13,843 altered m6A methylated peaks and found highest in chromosomes 1, 2, and 3. Analysis uncovered 119 overlapping genes and clusters into 32 up-regulated genes with 56 up-hyper peaks, 8 up-regulated genes with 9 up-hypo peaks, 12 down-regulated genes with 14 down-hyper peaks, and 28 down-regulated genes with 40 down-hypo peaks. A significant increase in the SIM2 m6A and RNA level led us to perform correlation analysis between the SIM2SV and m6A RNA regulators. SIM2SV was significantly correlated with YTHDF1 m6A-readers and m6A-NTMT1 writer, suggesting important roles of SIM2SV in CRC oncogenicity. m6A-sequencing identified m6A enrichment in 5’-UTR of SIM2SV gene which further verified. siNTMT1 and siYTHDF1 manipulation in HCT116 and RKO cell lines verified a decrease in SIM2SV gene/protein expression, and m6A level. Knockdown effects also showed decrease in cell proliferation, clonogenicity and induced cell cycle arrest in the G2/M phase for NTMT1 and YTHDF1 versus SIM2 Knockdown showed cell cycle arrest in S/G2 phase. Our investigation revealed the role of new writer NTMT1 for methylated SIM2SV gene expression in colorectal cancer proliferation via m6A-YTHDF1(as “decoder”) dependent manner. Further investigation on m6A modification specifically on SIM2 mRNA revealed the essential roles of its writer NTMT1 and its reader YTHDF1 in CRC development, evidently supporting the importance of the unique landscape of m6A epigenetic modification in colorectal neoplasm, which not only advance our understanding of CRC pathobiology but also provides a new set of molecular targets for building up effective tools to fight CRC. Citation Format: Sudhir Kumar Rai, Ting Gong, Zitong Gao, Yujia Qin, Matthew Huo, Ken Nakastu, Hua Yang, Yuanyuan Fu, Lang Wu, Mayumi Jijiwa, Masaki Nasu, Shaoqiu Chen, Gang Huang, Peiwen Fei, Youping Deng. Global epitranscriptomic and transcriptomic footprint revealed upregulation of methylated single minded 2-small variant (meSIM2-SV) in colorectal cancer (CRC) by NTMT1(METTL11A) via m6A-YTHDF1-dependent manner [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7075.

Abstract 3168: Amphiphilic dendrimer-mediated siRNA delivery for precision regulation of cAMP pathway in cancer cells

Abstract Exchange proteins directly activated by cAMP (EPACs) are involved in multiple cellular processes. The two EPAC isoforms (EPAC1 and EPAC2) have fundamental differences in structure, expression pattern, and signaling specificity, indicating that they may function independently. Therefore, the highly specific regulation of EPAC1 and EPAC2 could be beneficial in targeting cAMP pathway-related therapies. Small RNA molecules could theoretically target genetic components based on Watson-Crick base pairing, offering a unique and promising approach to achieve precision medicine. In this study, we successfully design small interfere (si)RNAs that specifically target EPAC1 and 2, without cross-reactivity with other isoforms. The use of the amphiphilic dendrimer (AD) efficiently delivers siRNAs, resulting in significant down-regulations of EPAC1 and 2 mRNA and protein expressions in multiple cancer cells, including ovarian, breast, colon, and pancreatic cancers. Functional analysis demonstrate that EPAC1 and EPAC2 regulate cancer progression depending on different mechanisms. siEPAC2-AD is more potent compared to siEPAC1-AD in suppressing cell proliferation by altering energy metabolism. Hence, this siEPACs-AD system not only enhances the drug specificity and reduces potential side effects, but also provides a new strategy for precision pharmaceutical control of the cAMP/PKA/EPAC signaling pathway for cancer treatment. Keywords: EPAC1; EPAC2; siRNA; amphiphilic dendrimer; cAMP signaling; cancer Citation Format: Wanjun Yuan, Zhengyin Gao, Ling Peng, Leo Tsz On Lee. Amphiphilic dendrimer-mediated siRNA delivery for precision regulation of cAMP pathway in cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3168.

Identification of CAF-related lncRNAs at the pan-cancer level represents a potential carcinogenic risk.

Cancer-associated fibroblasts (CAFs) are increasingly recognized as playing a crucial role in regulating cancer progression and metastasis. These cells can be activated by long non-coding RNAs (lncRNAs), promoting the malignant biological processes of tumor cells. Therefore, it is essential to understand the regulatory relationship between CAFs and lncRNAs in cancers. Here, we identified CAF-related lncRNAs at the pan-cancer level to systematically predict their potential regulatory functions. The identified lncRNAs were also validated using various external data at both tissue and cellular levels. This study has revealed that these CAF-related lncRNAs exhibit expression perturbations in cancers and are highly correlated with the infiltration of stromal cells, particularly fibroblasts and endothelial cells. By prioritizing a list of CAF-related lncRNAs, we can further distinguish patient subtypes that show survival and molecular differences. In addition, we have developed a web server, CAFLnc (https://46906u5t63.zicp.fun/CAFLnc/), to visualize our results. In conclusion, CAF-related lncRNAs hold great potential as a valuable resource for comprehending lncRNA functions and advancing the identification of biomarkers for cancer progression and therapeutic targets in cancer treatment.

METTL16 deficiency attenuates apoptosis through translational control of extrinsic death receptor during nutrient deprivation

METTL16 is a well-characterized m6A methyltransferase that has been reported to contribute to tumorigenesis in various types of cancer. However, the effect of METTL16 on tumor progression under restricted nutrient conditions, which commonly occur in tumor microenvironment, has yet to be elucidated. Herein, our study initially reported the inhibitory effect of METTL16 depletion on apoptosis under amino acid starvation conditions. Mechanistically, we determined that the METTL16 knockdown represses the expression of extrinsic death receptors at both transcription and translation levels. Depletion of METTL16 prevented protein synthesis of GCN2, resulting in diminished ATF4 expression in a GCN2-eIF2α-dependent manner. Reduction of ATF4 further declined the expression of apoptotic receptor protein DR5. Meanwhile, METTL16 deficiency directly hampered protein synthesis of FADD and DR5, thereby impairing apoptosis and promoting cancer cell survival. Taken together, our study provides novel evidence for the involvement of METTL16 in regulating cancer progression, suggesting that METTL16 as a potential therapeutic target for cancer treatment.

A novel mitochondrial unfolded protein response-related risk signature to predict prognosis, immunotherapy and sorafenib sensitivity in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a common cause of cancer-associated death worldwide. The mitochondrial unfolded protein response (UPRmt) not only maintains mitochondrial integrity but also regulates cancer progression and drug resistance. However, no study has used the UPRmt to construct a prognostic signature for HCC. This work aimed to establish a novel signature for predicting patient prognosis, immune cell infiltration, immunotherapy, and chemotherapy response based on UPRmt-related genes (MRGs). Transcriptional profiles and clinical information were obtained from the TCGA and ICGC databases. Cox regression and LASSO regression analyses were applied to select prognostic genes and develop a risk model. The TIMER algorithm was used to investigate immunocytic infiltration in the high- and low-risk subgroups. Here, two distinct clusters were identified with different prognoses, immune cell infiltration statuses, drug sensitivities, and response to immunotherapy. A risk score consisting of seven MRGs (HSPD1, LONP1, SSBP1, MRPS5, YME1L1, HDAC1 and HDAC2) was developed to accurately and independently predict the prognosis of HCC patients. Additionally, the expression of core MRGs was confirmed by immunohistochemistry (IHC) staining, single-cell RNA sequencing, and spatial transcriptome analyses. Notably, the expression of prognostic MRGs was significantly correlated with sorafenib sensitivity in HCC and markedly downregulated in sorafenib-treated HepG2 and Huh7 cells. Furthermore, the knockdown of LONP1 decreased the proliferation, invasion, and migration of HepG2 cells, suggesting that upregulated LONP1 expression contributed to the malignant behaviors of HCC cells. To our knowledge, this is the first study to investigate the consensus clustering algorithm, prognostic potential, immune microenvironment infiltration and drug sensitivity based on the expression of MRGs in HCC. In summary, the UPRmt-related classification and prognostic signature could assist in determining the prognosis and personalized therapy of HCC patients from the perspectives of predictive, preventative and personalizedmedicine.

CircANXA4 (hsa_circ_0055087) regulates the miR-1256/PRM1 axis to promote tumor progression in colorectal cancer

Colorectal cancer (CRC) incidence ranks third among malignant cancers with a high propensity for distant metastasis. Despite continuous efforts to improve treatment, the prognosis especially in patients with advanced distant metastasis is low. The mechanism of development and progression of CRC is not fully understood. Non-coding RNAs (ncRNAs) have emerged as essential regulators in cancer progression. Here, we aim to dissect the role of one critical ncRNA, circANXA4, in CRC progression. CircANXA4 expression was analyzed by the GEO database. Differentially expressed circRNAs were identified by the Limma package R software. Expression of circANXA4 and miR-1256 was detected by qRT-PCR. The regulation of circANXA4 on cell proliferation and progression was confirmed with the cell viability assay using cell counting kit-8 (CCK-8) and transwell migration assay. RNA pull-down assay, RNA immunoprecipitation (RIP), and western blot were used to determine the interaction between circANXA4, miR-1256, and protamine1 (PRM1). CircANXA4 was upregulated in both CRC tissues and cell lines. Knockdown of circANXA4 effectively reduced cell proliferation, progression, and migration. Additionally, silencing circANXA4 remarkably increased miR-1256 expression, while reducing PRM1 expression, thereby demonstrating that circANXA4 downregulates miR-1256 expression through a complementary binding site. Rescue experiments revealed the interactions between circANXA4, miR-1256, and PRM1. Pearson correlation analysis revealed that circANXA4 expression positively correlated with PRM1 expression and miR-1256 expression inversely correlated with PRM1 expression. In sum, we demonstrated that circANXA4 promotes cancer cell proliferation and progression by sponging miR-1256 and upregulating PRM1 in CRC.

Circular RNA circWNK1 inhibits the progression of gastric cancer via regulating the miR-21-3p/SMAD7 axis.

Gastric cancer (GC) is a highly aggressive malignancy with limited treatment options for advanced-stage patients. Recent studies have highlighted the role of circular RNA (circRNA) as a novel regulator of cancer progression in various malignancies. However, the underlying mechanisms by which circRNA contributes to the development and progression of GC remain poorly understood. In this study, we utilized microarrays and real-time quantitative polymerase chain reaction (qRT-PCR) to identify and validate a downregulated circRNA, hsa_circ_0003251 (referred to as circWNK1), in paired GC and normal tissues. Through a series of invitro and invivo gain-of-function and loss-of-function assays, we demonstrated that circWNK1 exerts inhibitory effects on the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of GC cells. Additionally, we discovered that circWNK1 acts as a competitive endogenous RNA (ceRNA) for SMAD7 by sequestering miR-21-3p. Our findings were supported by comprehensive biological information analysis, as well as RNA pull-down, luciferase reporter gene, and western blot assays. Notably, the downregulation of circWNK1 in GC cells resulted in reduced SMAD7 expression, subsequently activating the TGF-β signaling pathway. Collectively, our study reveals that circWNK1 functions as a tumor suppressor in GC by regulating the miR-21-3p/SMAD7-mediated TGF-β signaling pathway. Furthermore, circWNK1 holds promise as a potential biomarker for the diagnosis and treatment of GC.

Tanreqing suppresses the proliferation and migration of non-small cell lung cancer cells by mediating the inactivation of the HIF1α signaling pathway via exosomal circ-WDR78

Circular RNAs (circRNAs) have emerged as regulators of cancer progression, including non-small cell lung cancer (NSCLC). Tanreqing (TRQ), a traditional Chinese medicine, is used clinically for respiratory diseases. RT-qPCR quantified circ-WDR78 expression in NSCLC cells. Cell growth, apoptosis, invasion, and migration were assessed by functional assays. RNA-binding protein immunoprecipitation (RIP), luciferase reporter, and RNA pull-down assays determined the competing endogenous RNA (ceRNA) network of circ-WDR78. The interaction between HIF1α and CD274 (PD-L1) promoter was analyzed by chromatin immunoprecipitation (ChIP). Circ-WDR78 expression was up-regulated in TRQ-treated NSCLC cells. Functionally, circ-WDR78 exhibited anti-tumor effects in these cells. Additionally, circ-WDR78 could also induce reactive oxygen species (ROS) accumulation by down-regulating HIF1α expression, promoting autophagy. Mechanistically, circ-WDR78 destabilizes HIF1α via the miR-1265/FBXW8 axis. TRQ-induced exosome secretion from NSCLC cells inhibits PD-L1 expression, preventing immune escape. We found that TRQ-treated NSCLC cells secrete exosomes to transmit circ-WDR78 to untreated NSCLC cells, inhibiting the malignancy of recipient tumor cells. In conclusion, TRQ inhibits NSCLC cell proliferation, invasion, and migration through exosomal circ-WDR78-mediated inactivation of the HIF1α signaling pathway, providing potential insight into TRQ injection for NSCLC treatment. Communicated by Ramaswamy H. Sarma

Abstract B033: Multiplex analysis of the tumor immune microenvironment during treatment with atezolizumab/pelareorep/letrozole reveals novel immune-tumor interactions

Abstract Background: Pelareorep (pela) is a non-modified intravenously administered oncolytic reovirus exhibiting effective tumor suppression through both innate and adaptive immune responses, as well as direct tumor lysis. Findings from the AWARE-1 window of opportunity study previously demonstrated the synergistic potential of combining pela with atezolizumab (atezo), showcasing promising immunological reactions within tumors of early breast cancer (eBC) patients. To gain deeper insights into the complex tumor immune microenvironment (TiME) pre- and post-treatment, we employed imaging mass cytometry (IMC) to conduct high-dimensional, single-cell analysis of tissue samples. Methods: Patients (n=10) received pela (days 1, 2 and 8, 9), atezolizumab (day 3), and letrozole (day 1 to 21). Tumor biopsies (FFPE samples) were collected pre-treatment on day 3 (prior to atezolizumab administration) and on day ~21 (surgical excision). Samples from 8 out of 10 patients were subjected to IMC with a comprehensive panel of 37 antibodies for single cell investigation of TiME changes. Tumor, proliferation, T cell, macrophage, NK, and immunoregulatory markers were included in the panel. Results: Our first pass analysis of IMC images, showed an increase in proliferating (Ki67+) cytotoxic T cells adjacent to apoptotic (caspase 3+) tumor cells post-treatment (both D3 and D21) samples indicating immunogenic cell death. Conversely, we observed a decrease in Ki67+ and ER-positive tumor cells after treatment indicating decreased tumor cell proliferation and hormone expression. In 3 out of 8 patients, treatment was associated with a shift in monocyte/macrophages from an M1 (CD68+/CD163-) to M2 (CD68+/CD163+) phenotype associated with significant tumor infiltration. Surprisingly, in these patients we also noted a significant increase in apoptotic M2 macrophages on D21. Consistent with the known immune priming effects of pela, both PD-1 and PD-L1 increased on D3. Subsequently, on day 21, post atezo, tumor PD-L1 decreased on tumor cells while PD-1 expression persisted. Pela induced IDO expression on both tumor and monocyte/macrophage cells. Unlike its effect on PD-L1, atezo did not appear to attenuate IDO expression on day 21. We were also able to detect a treatment related increase in immune cell perivascular localization on D3 providing further evidence of TiME priming. Conclusions: The immune system plays a crucial role in regulating cancer progression; however, our understanding of immune interactions with tumors remains limited. Our study utilizing IMC revealed complex immune-tumor interactions changes during treatment with atezo/pela/letrozole. These findings provide valuable insights into the intricate dynamics of the TiME and may inform new therapeutic combination approaches in breast cancer treatment. Citation Format: Homa Dadrastoussi, Julian Olea, Eduardo Fernandez Hernandez, Hugo Lara Martinez, Kaijin Wu, Houra Loghmani, Thomas Heineman, Richard Trauger, Matt Coffey, Akil Merchant, Kevin Kelly. Multiplex analysis of the tumor immune microenvironment during treatment with atezolizumab/pelareorep/letrozole reveals novel immune-tumor interactions [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2023 Oct 1-4; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Immunol Res 2023;11(12 Suppl):Abstract nr B033.

Abstract A021: Nutrient competition in the tumor microenvironment alters NK cell metabolism in Pancreatic Cancer

Abstract Tumor cells present constant nutritional demand of macronutrients and micronutrients for their rapid growth needs. Often this nutrient limitation hampers the function of anti-tumor immune cells, which need basal energy levels to execute cytotoxic effects against malignant cells. Hence, we investigated nutrient limitation-induced metabolic alterations in NK cells that regulate the anti-tumor activity of NK cells. Using 2D cultures and PDAC organoid models, we demonstrate that pancreatic tumor cells exhaust vitamin B6 (VB6) in the co-culture milieu, causing reduced killing activity of NK cells. Additionally, we demonstrate that PDAC patients have significantly reduced plasma VB6 as compared to the healthy counterparts. This data aligns with the epidemiological studies showing that VB6 intake reduces the risk of pancreatic cancer incidence. Moreover, we noted a significant reduction in circulating VB6 in the pancreatic tumor-bearing mice as compared to healthy counterparts. Utilizing mass spectrometry-based metabolomics we noted that limitation of the VB6 prevents glycogen breakdown in NK cells. This was validated by follow up electron microscopy-based studies that demonstrated glycogen depots in NK cells that were very prominent upon inhibiting glycogenolysis. Metabolic tracing studies demonstrated that NK cells require VB6 for intracellular glycogen breakdown. Correspondingly, knocking down glycogen phosphorylase, a key enzyme involved in glycogen breakdown abrogated anti-tumoral NK cell function. Notably, supplementation of co-cultures in 2D and organoid models and in vivo orthotopic mouse models, with VB6 restored NK cell function against pancreatic tumor cells. In parallel, we observed dependence of tumor cell metabolism on VB6 for sustaining growth. Accordingly, we observed that tumor cells actively deplete VB6 in tumor microenvironments, as observed by comparing VB6 levels in circulation and in tumor interstitial fluids. Finally, we observed that VB6 supplementation in combination with inhibitors targeting VB6-driven metabolic pathway dependencies in tumor cells effectively enhances NK cell frequency and diminishes tumor burden in vivo. These studies demonstrate a novel role of glycogen breakdown as a critical energy source for activated NK cells and demonstrate, for the first time a key role of glycogenolysis in NK cell cytotoxic activities. Our results expand the understanding of the critical role of micronutrients (vitamin B6) in regulating cancer progression and anti-tumor immunity and open new avenues for developing NK cell-based immunotherapies for PDAC patients. Citation Format: Kamiya Mehla. Nutrient competition in the tumor microenvironment alters NK cell metabolism in Pancreatic Cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2023 Oct 1-4; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Immunol Res 2023;11(12 Suppl):Abstract nr A021.

LncRNA TDRKH-AS1 promotes breast cancer progression via the miR-134-5p/CREB1 axis

BackgroundBreast cancer (BC) is a prevalent malignancy with complex etiology and varied clinical behavior. Long non-coding RNAs (lncRNAs) have emerged as key regulators in cancer progression, including BC. Among these, lncRNA TDRKH-AS1 has been implicated in several cancers, but its role in BC remains unclear.MethodsWe conducted a comprehensive investigation to elucidate the role of TDRKH-AS1 in BC. Clinical samples were collected from BC patients, and BC cell lines were cultured. Bioinformatics analysis using the starBase database was carried out to assess TDRKH-AS1 expression levels in BC tissue samples. Functional experiments, including knockdown, colony formation, CCK-8, Transwell, and wound-healing assays, were conducted to determine the role of TDRKH-AS1 in BC cell proliferation and invasion. Luciferase reporter and RIP assays were used to examine the interactions between TDRKH-AS1 and miR-134-5p. In addition, the downstream target gene of miR-134-5p, cAMP response element-binding protein 1 (CREB1), was identified and studied using various methods, including RT-qPCR, immunoprecipitation, and rescue experiments. In vivo experiments using mouse tumor xenograft models were conducted to examine the role of TDRKH-AS1 in BC tumorigenesis.ResultsTDRKH-AS1 was found to be significantly upregulated in BC tissues and cell lines. High TDRKH-AS1 expression correlated with advanced BC stages and worse patient outcomes. Knockdown of TDRKH-AS1 led to decreased BC cell proliferation and invasion. Mechanistically, TDRKH-AS1 acted as a sponge for miR-134-5p, thereby reducing the inhibitory effects of miR-134-5p on CREB1 expression. Overexpression of CREB1 partially rescued the effects of TDRKH-AS1 knockdown in BC cells. In vivo studies further confirmed the tumor-promoting role of TDRKH-AS1 in BC.ConclusionsOur study unveiled a novel regulatory axis involving TDRKH-AS1, miR-134-5p, and CREB1 in BC progression. TDRKH-AS1 functioned as an oncogenic lncRNA by promoting BC cell proliferation and invasion through modulation of the miR-134-5p/CREB1 axis. These findings highlighted TDRKH-AS1 as a potential diagnostic biomarker and therapeutic target for BC treatment.

Identifying individualized prognostic signature and unraveling the molecular mechanism of recurrence in early-onset colorectal cancer

BackgroundThe incidence and mortality of early-onset colorectal cancer (EOCRC; < 50 years old) is increasing worldwide, with a high recurrence rate. The inherent heterogeneity of EOCRC makes its treatment challenging. Hence, to further understand the biology and reveal the molecular mechanisms of EOCRC, a recurrence risk signature is needed to guide clinical management.MethodsBased on the relative expression orderings (REOs) of genes in each sample, a prognostic signature was developed and validated utilizing multiple independent datasets. The underlying molecular mechanisms between distinct prognostic groups were explored via integrative analysis of multi-omics data.ResultsThe prognostic signature consisting of 6 gene pairs (6-GPS) could predict the recurrence risk for EOCRC at the individual level. High-risk EOCRC classified by 6-GPS showed a poor prognosis but a good response to adjuvant chemotherapy. Moreover, high-risk EOCRC was characterized by epithelial-mesenchymal transition (EMT) and enriched angiogenesis, and had higher mutation burden, immune cell infiltration, and PD-1/PD-L1 expression. Furthermore, we identified four genes associated with relapse-free survival in EOCRC, including SERPINE1, PECAM1, CDH1, and ANXA1. They were consistently differentially expressed at the transcriptome and proteome levels between high-risk and low-risk EOCRCs. They were also involved in regulating cancer progression and immune microenvironment in EOCRC. Notably, the expression of SERPINE1 and ANXA1 positively correlated with M2-like macrophage infiltration.ConclusionOur results indicate that 6-GPS can robustly predict the recurrence risk of EOCRC, and that SERPINE1, PECAM1, CDH1, and ANXA1 may serve as potential therapeutic targets. This study provides valuable information for the precision treatment of EOCRC.

Histone lactylation regulates cancer progression by reshaping the tumor microenvironment.

As a major product of glycolysis and a vital signaling molecule, many studies have reported the key role of lactate in tumor progression and cell fate determination. Lactylation is a newly discovered post-translational modification induced by lactate. On the one hand, lactylation introduced a new era of lactate metabolism in the tumor microenvironment (TME), and on the other hand, it provided a key breakthrough point for elucidation of the interaction between tumor metabolic reprogramming and epigenetic modification. Studies have shown that the lactylation of tumor cells, tumor stem cells and tumor-infiltrating immune cells in TME can participate in the development of cancer through downstream transcriptional regulation, and is a potential and promising tumor treatment target. This review summarized the discovery and effects of lactylation, as well as recent research on histone lactylation regulating cancer progression through reshaping TME. We also focused on new strategies to enhance anti-tumor effects via targeting lactylation. Finally, we discussed the limitations of existing studies and proposed new perspectives for future research in order to further explore lactylation targets. It may provide a new way and direction to improve tumor prognosis.

Emerging roles of interactions between ncRNAs and other epigenetic modifications in breast cancer.

Up till the present moment, breast cancer is still the leading cause of cancer-related death in women worldwide. Although the treatment methods and protocols for breast cancer are constantly improving, the long-term prognosis of patients is still not optimistic due to the complex heterogeneity of the disease, multi-organ metastasis, chemotherapy and radiotherapy resistance. As a newly discovered class of non-coding RNAs, ncRNAs play an important role in various cancers. Especially in breast cancer, lncRNAs have received extensive attention and have been confirmed to regulate cancer progression through a variety of pathways. Meanwhile, the study of epigenetic modification, including DNA methylation, RNA methylation and histone modification, has developed rapidly in recent years, which has greatly promoted the attention to the important role of non-coding RNAs in breast cancer. In this review, we carefully and comprehensively describe the interactions between several major classes of epigenetic modifications and ncRNAs, as well as their different subsequent biological effects, and discuss their potential for practical clinical applications.

Multiscale network modeling reveals the gene regulatory landscape driving cancer prognosis in 32 cancer types.

Cancer is a complex disease with diverse molecular mechanisms that affect patient prognosis. Network-based approaches are effective in revealing a holistic picture of cancer prognosis and gene interactions. However, a comprehensive landscape of coexpression networks and prognostic gene modules across multiple cancer types remains elusive. In this study, we performed a systematic analysis of coexpression networks in 32 cancer types. Our analysis identified 4749 prognostic modules that play a vital role in regulating cancer progression. Integrative epigenomic analyses revealed that these modules were regulated by interactions between gene expression and methylation. Coregulated genes of network modules were enriched in chromosome cytobands and preferentially localized in open chromatin regions. The preserved network modules formed 330 module clusters that resided in chromosome hot spots. The cancer-type-specific prognostic modules participated in unique essential biological processes in different cancer types. Overall, our study provides rich resources of prevalent gene networks and underlying multiscale regulatory mechanisms driving cancer prognosis, which lay a foundation for biomarker discovery and therapeutic target development.