circCAPRIN1 interacts with STAT2 to promote tumor progression and lipid synthesis via upregulating ACC1 expression in colorectal cancer

Interplay between JAK/STAT pathway and non-coding RNAs in different cancers

Progress in the identification of core multi-protein modules within JAK/STAT pathway has enabled researchers to develop a better understanding of the linchpin role of deregulated signaling cascade in carcinogenesis and metastasis. More excitingly, complex interplay between JAK/STAT pathway and non-coding RNAs has been shown to reprogramme the outcome of signaling cascade and modulate immunological responses within tumor microenvironment. Wealth of information has comprehensively illustrated that most of this complexity regulates the re-shaping of the immunological responses. Increasingly sophisticated mechanistic insights have illuminated fundamental role of STAT-signaling in polarization of macrophages to M2 phenotype that promotes disease aggressiveness. Overall, JAK/STAT signaling drives different stages of cancer ranging from cancer metastasis to the reshaping of the tumor microenvironment. JAK/STAT signaling has also been found to play role in the regulation of infiltration and activity of natural killer cells and CD4/CD8 cells by PD-L1/PD-1 signaling. In this review, we have attempted to set spotlight on regulation of JAK/STAT pathway by microRNAs, long non-coding RNAs and circular RNAs in primary tumors and metastasizing tumors. Therefore, existing knowledge gaps need to be addressed to propel this fledgling field of research to the forefront and bring lncRNAs and circRNAs to the frontline of clinical practice. Leveraging the growing momentum will enable interdisciplinary researchers to gain transition from segmented view to a fairly detailed conceptual continuum.

CircEZH2 promotes gallbladder cancer progression and lipid metabolism reprogramming through the miR-556-5p/SCD1 axis

Gallbladder cancer (GBC) is characterized by a high degree of malignancy and a poor prognosis. This study revealed that circEZH2 was frequently upregulated in GBC tissues and correlated with advanced tumor-node-metastasis (TNM) stage in GBC patients. In vitro and in vivo experiments confirmed that circEZH2 promoted the proliferation and inhibited the ferroptosis of GBC. Besides, this study discovered that circEZH2 regulated lipid metabolism reprogramming in GBC cells. Mechanistically, circEZH2 promotes SCD1 expression by sponging miR-556-5p in GBC cells. In addition, IGF2BP2 enhances the stability of circEZH2 in an m6A-dependent manner, while circEZH2 suppresses the ubiquitination and degradation of IGF2BP2 by binding to IGF2BP2. Taken together, our findings indicated that circEZH2, upregulated via a positive feedback loop between circEZH2 and IGF2BP2, promotes GBC progression and lipid metabolism reprogramming through the miR-556-5p/SCD1 axis in GBC. circEZH2 may serve as a potential therapeutic target for GBC.

Fatty acid metabolism-related enzymes in colorectal cancer metastasis: from biological function to molecular mechanism

Colorectal cancer (CRC) is a highly aggressive and life-threatening malignancy that metastasizes in ~50% of patients, posing significant challenges to patient survival and treatment. Fatty acid (FA) metabolism regulates proliferation, immune escape, metastasis, angiogenesis, and drug resistance in CRC. FA metabolism consists of three pathways: de novo synthesis, uptake, and FA oxidation (FAO). FA metabolism-related enzymes promote CRC metastasis by regulating reactive oxygen species (ROS), matrix metalloproteinases (MMPs), angiogenesis and epithelial-mesenchymal transformation (EMT). Mechanistically, the PI3K/AKT/mTOR pathway, wnt/β-catenin pathway, and non-coding RNA signaling pathway are regulated by crosstalk of enzymes related to FA metabolism. Given the important role of FA metabolism in CRC metastasis, targeting FA metabolism-related enzymes and their signaling pathways is a potential strategy to treat CRC metastasis.

Circular RNA hsa_circ_0001610 promotes prostate cancer progression by sponging miR-1324 and upregulating PTK6

Prostate cancer (PCa) incidence and cancer-related deaths are both high in the male population. Once castration-resistant prostate cancer (CRPC) has developed, PCa can be difficult to manage. Circular RNAs (circRNAs) play essential roles in the regulation of carcinogenesis and cancer progression. In CRPC, however, the potential molecular mechanisms and biological functions of circRNAs are yet to be defined. In this study, we conducted RNA sequencing on four hormone-sensitive prostate cancer (HSPC) tumor tissue samples and three CRPC samples. We recognized hsa_circ_0001610, a novel circRNA that was highly expressed in the cells and tissue of CRPC. We used quantitative real-time PCR (qRT-PCR) to evaluate hsa_circ_0001610 expression. We conducted in vivo and in vitro experiments and found that hsa_circ_0001610 overexpression caused PCa cells to proliferate and migrate and caused enzalutamide resistance. In contrast, the opposite results were found for hsa_circ_0001610 knockdown. We used Western blot, dual-luciferase reporter assays, RNA immunoprecipitation (RIP), qRT-PCR, and rescue experiments to reveal the underlying mechanisms of hsa_circ_0001610. Mechanistically, hsa_circ_0001610 acted as a molecular sponge for miR-1324 and thus reversed its inhibitory effect on its target gene PTK6. As a result, the PTK6 expression was enhanced, which accelerated PCa progression. The findings of this study confirmed that hsa_circ_0001610 drives the progression of PCa through the hsa_circ_0001610/miR-1324/PTK6 axis. Thus, hsa_circ_0001610 is potentially an effective therapeutic target and specific biomarker for advanced PCa.

IGF2BP2-modified circular RNA circCHD7 promotes endometrial cancer progression via stabilizing PDGFRB and activating JAK/STAT signaling pathway

Circular RNAs (circRNAs) represent a class of covalently closed, single-stranded RNAs and have been linked to cancer progression. N6-methyladenosine (m6A) methylation is a ubiquitous RNA modification in cancer cells. Increasing evidence suggests that m6A can mediate the effects of circRNAs in cancer biology. In contrast, the post-transcriptional systems of m6A and circRNA in the progression of endometrial cancer (EC) remain obscure. The current study identified a novel circRNA with m6A modification, hsa_circ_0084582 (circCHD7), which was upregulated in EC tissues. Functionally, circCHD7 was found to promote the proliferation of EC cells. Mechanistically, circCHD7 interacted with insulin-like growth factor 2 mRNA-binding protein (IGF2BP2) to amplify its enrichment. Moreover, circCHD7 increased the mRNA stability of platelet-derived growth factor receptor beta (PDGFRB) in an m6A-dependent manner, thereby enhancing its expression. In addition, the circCHD7/IGF2BP2/PDGFRB axis activated the JAK/STAT signaling pathway and promoted EC cell proliferation. In conclusion, these findings provide new insights into the regulation of circRNA-mediated m6A modification, and the new "circCHD7-PDGFRB" model of regulation offers new perspectives on circCHD7 as a potential target for EC therapy.

CircATF6 inhibits hepatocellular carcinoma progression by suppressing calreticulin-mediated Wnt/β-catenin signaling pathway

Circular RNAs (circRNAs) are covalently closed, single-stranded RNAs that play critical roles in various biological processes and diseases, including cancers. However, the functions and mechanisms of circRNAs in hepatocellular carcinoma (HCC) need further clarification. Here, we identified and confirmed that circATF6 is downregulated in HCC tissues and negatively associated with the overall survival of HCC patients. Ectopic overexpression of circATF6 inhibits malignant phenotypes of HCC cells in vitro and in vivo, while knockdown of circATF6 had opposite effects. Mechanistically, we found that circATF6 bound to calreticulin (CALR) protein and acted as a scaffold to enhance the interaction of CALR with calpain2 (CAPN2), which promoted the degradation of CALR by its enzymatic activity. Moreover, we found that circATF6 inhibited HCC cells by suppressing CALR-mediated wnt/β-catenin signaling pathway. Taken together, our findings suggest that circATF6 is a potential prognostic biomarker and therapeutic target for HCC.

Roles of circRNAs in the progression of colorectal cancer: novel strategies for detection and therapy

Endogenous noncoding RNAs with a covalently closed loop are known as circular RNAs (circRNAs). Recently, published works have revealed that circRNAs, which act as microRNA sponges, are critical for the biological behavior of several kinds of malignancies, including tumor cell proliferation, apoptosis, invasion, and metastasis. Additionally, there is a significant correlation between circRNAs and tumor resistance, stage, prognosis, and size. At present, colorectal cancer (CRC) is one of the most serious malignant tumors for human health. CircRNAs could represent potential targets to use in the prevention, diagnosis, and therapy of CRC, according to many studies. To fully comprehend the role of circRNAs in the incidence and progression of CRC, this review outlines the regulatory role and mechanisms of circRNAs in CRC and assesses their potential relevance as diagnostic and treatment possibilities for CRC. Our goal is to offer meaningful biological information for clinical evaluation and decision-making process for CRC treatment.

Identifying differentially expressed genes in goat mammary epithelial cells induced by overexpression of SOCS3 gene using RNA sequencing

The suppressor of cytokine signaling 3 (SOCS3) is a key signaling molecule that regulates milk synthesis in dairy livestock. However, the molecular mechanism by which SOCS3 regulates lipid synthesis in goat milk remains unclear. This study aimed to screen for key downstream genes associated with lipid synthesis regulated by SOCS3 in goat mammary epithelial cells (GMECs) using RNA sequencing (RNA-seq). Goat SOCS3 overexpression vector (PC-SOCS3) and negative control (PCDNA3.1) were transfected into GMECs. Total RNA from cells after SOCS3 overexpression was used for RNA-seq, followed by differentially expressed gene (DEG) analysis, functional enrichment analysis, and network prediction. SOCS3 overexpression significantly inhibited the synthesis of triacylglycerol, total cholesterol, non-esterified fatty acids, and accumulated lipid droplets. In total, 430 DEGs were identified, including 226 downregulated and 204 upregulated genes, following SOCS3 overexpression. Functional annotation revealed that the DEGs were mainly associated with lipid metabolism, cell proliferation, and apoptosis. We found that the lipid synthesis-related genes, STAT2 and FOXO6, were downregulated. In addition, the proliferation-related genes BCL2, MMP11, and MMP13 were upregulated, and the apoptosis-related gene CD40 was downregulated. In conclusion, six DEGs were identified as key regulators of milk lipid synthesis following SOCS3 overexpression in GMECs. Our results provide new candidate genes and insights into the molecular mechanisms involved in milk lipid synthesis regulated by SOCS3 in goats.

Casual associations between blood metabolites and colon cancer

BACKGROUND

Limited knowledge exists regarding the casual associations linking blood metabolites and the risk of developing colorectal cancer.

AIM

To investigate causal associations between blood metabolites and colon cancer.

METHODS

The study utilized a two-sample Mendelian randomization (MR) analysis to investigate the causal impact of 486 blood metabolites on colorectal cancer. The primary method of analysis used was the inverse variance weighted model. To further validate the results several sensitivity analyses were performed, including Cochran's Q test, MR-Egger intercept test, and MR robust adjusted profile score. These additional analyses were conducted to ensure the reliability and robustness of the findings.

RESULTS

After rigorous selection for genetic variation, 486 blood metabolites were included in the MR analysis. We found Mannose [odds ratio (OR) = 2.09 (1.10-3.97), P = 0.024], N-acetylglycine [OR = 3.14 (1.78-5.53), P = 7.54 × 10-8], X-11593-O-methylascorbate [OR = 1.68 (1.04-2.72), P = 0.034], 1-arachidonoylglycerophosphocholine [OR = 4.23 (2.51-7.12), P = 6.35 × 10-8] and 1-arachidonoylglycerophosphoethanolamine 4 [OR = 3.99 (1.17-13.54), P = 0.027] were positively causally associated with colorectal cancer, and we also found a negative causal relationship between Tyrosine [OR = 0.08 (0.01-0.63), P = 0.014], Urate [OR = 0.25 (0.10-0.62), P = 0.003], N-acetylglycine [0.73 (0.54-0.98), P = 0.033], X-12092 [OR = 0.89 (0.81-0.99), P = 0.028], Succinylcarnitine [OR = 0.48 (0.27-0.84), P = 0.09] with colorectal cancer. A series of sensitivity analyses were performed to confirm the rigidity of the results.

CONCLUSION

This study showed a causal relationship between 10 blood metabolites and colorectal cancer, of which 5 blood metabolites were found to be causal for the development of colorectal cancer and were confirmed as risk factors. The other five blood metabolites are protective factors.

METTL5 promotes gastric cancer progression via sphingomyelin metabolism

BACKGROUND

The treatment of gastric cancer (GC) has caused an enormous social burden worldwide. Accumulating studies have reported that N6-methyladenosine (m6A) is closely related to tumor progression. METTL5 is a m6A methyltransferase that plays a pivotal role in maintaining the metabolic stability of cells. However, its aberrant regulation in GC has not been fully elucidated.

AIM

To excavate the role of METTL5 in the development of GC.

METHODS

METTL5 expression and clinicopathological characteristics were analyzed via The Cancer Genome Atlas dataset and further verified via immunohistochemistry, western blotting and real-time quantitative polymerase chain reaction in tissue microarrays and clinical samples. The tumor-promoting effect of METTL5 on HGC-27 and AGS cells was explored in vitro by Cell Counting Kit-8 assays, colony formation assays, scratch healing assays, transwell assays and flow cytometry. The tumor-promoting role of METTL5 in vivo was evaluated in a xenograft tumor model. The EpiQuik m6A RNA Methylation Quantification Kit was used for m6A quantification. Next, liquid chromatography-mass spectrometry was used to evaluate the association between METTL5 and sphingomyelin metabolism, which was confirmed by Enzyme-linked immunosorbent assay and rescue tests. In addition, we investigated whether METTL5 affects the sensitivity of GC cells to cisplatin via colony formation and transwell experiments.

RESULTS

Our research revealed substantial upregulation of METTL5, which suggested a poor prognosis of GC patients. Increased METTL5 expression indicated distant lymph node metastasis, advanced cancer stage and pathological grade. An increased level of METTL5 correlated with a high degree of m6A methylation. METTL5 markedly promotes the proliferation, migration, and invasion of GC cells in vitro. METTL5 also promotes the growth of GC in animal models. METTL5 knockdown resulted in significant changes in sphingomyelin metabolism, which implies that METTL5 may impact the development of GC via sphingomyelin metabolism. In addition, high METTL5 expression led to cisplatin resistance.

CONCLUSION

METTL5 was found to be an oncogenic driver of GC and may be a new target for therapy since it facilitates GC carcinogenesis through sphingomyelin metabolism and cisplatin resistance.

Biological functions of circRNA in regulating the hallmarks of gastrointestinal cancer (Review)

Circular RNA (circRNA) was first observed in the cytoplasm of eukaryotic cells in 1979, but it was not characterized in detail until 2012, when high‑throughput sequencing technology was more advanced and available. Consequently, the mechanism of circRNA formation and its biological function have been progressively elucidated by researchers. circRNA is abundant in eukaryotic cells and exhibits a certain degree of organization, timing and disease‑specificity. Additionally, it is poorly degradable, meeting the characteristics of an ideal clinical biomarker. In the present review, the recent research progress of circRNAs in digestive tract malignant tumors was primarily discussed. This included the roles, biological functions and clinical significance of circRNA, providing references for its research value and clinical potential in gastrointestinal cancer.

Circ_0007422 Knockdown Inhibits Tumor Property and Immune Escape of Colorectal Cancer by Decreasing PDL1 Expression in a miR-1256-Dependent Manner

Circular RNAs (circRNAs) are a group of important molecules involved in the progression of various cancers, including colorectal cancer (CRC). Here, we aim to investigate the role and molecular mechanism of circ_0007422 in regulating CRC malignant progression. The expression levels of circ_0007422, miR-1256, and PDL1 were detected by qRT-PCR. Cell viability, proliferation, apoptosis, invasion, and self-replication ability were analyzed by CCK-8, EdU, flow cytometry, transwell, and spheroid formation experiments, respectively. Protein levels were determined by western blotting assay. CRC cells were co-cultured with CD8 + T cells, phytohemagglutinin-stimulated peripheral blood mononuclear cells (PBMCs), or cytokine-induced killer (CIK) cells in vitro, and CD8 + T-cell apoptosis, IFN-γ and TNF-α levels, and survival rate of CRC cells were analyzed to reveal the role of circ_0007422 in antitumor immunity. The relationship between miR-1256 and circ_0007422 or PDL1 was identified by a dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. A xenograft tumor model was established to verify the function of circ_0007422 in tumor growth in vivo. Immunohistochemistry (IHC) assay was used to detect positive expression rates of Ki67, E-cadherin, N-cadherin, and PDL1 expression in primary tumors from CRC cells. Circ_0007422 was upregulated in CRC tissues and cells and its knockdown inhibited proliferation, invasion, self-replication ability, and immune escape and promoted apoptosis of CRC cells. Additionally, circ_0007422 bound to miR-1256, which was identified to target PDL1. MiR-1256 inhibition reversed the effects of circ_0007422 knockdown on the tumor properties and immune escape of CRC cells. Moreover, miR-1256 introduction interacted with PDL1 to suppress proliferation, invasion, self-replication ability, and immune escape and promote apoptosis of CRC cells. Further, circ_0007422 knockdown hampered tumorigenesis of CRC cells in vivo. Circ_0007422 knockdown inhibited tumor property and immune escape of colorectal cancer through the miR-1256/PDL1 pathway, providing a potential novel therapeutic target for CRC.

The roles and molecular mechanisms of non-coding RNA in cancer metabolic reprogramming

One of the key features of cancer is energy metabolic reprogramming which is tightly related to cancer proliferation, invasion, metastasis, and chemotherapy resistance. NcRNAs are a class of RNAs having no protein-coding potential and mainly include microRNAs, lncRNAs and circRNAs. Accumulated evidence has suggested that ncRNAs play an essential role in regulating cancer metabolic reprogramming, and the altered metabolic networks mediated by ncRNAs primarily drive carcinogenesis by regulating the expression of metabolic enzymes and transporter proteins. Importantly, accumulated research has revealed that dysregulated ncRNAs mediate metabolic reprogramming contributing to the generation of therapeutic tolerance. Elucidating the molecular mechanism of ncRNAs in cancer metabolic reprogramming can provide promising metabolism-related therapeutic targets for treatment as well as overcome therapeutic tolerance. In conclusion, this review updates the latest molecular mechanisms of ncRNAs related to cancer metabolic reprogramming.

LncRNAs-circRNAs as Rising Epigenetic Binary Superstars in Regulating Lipid Metabolic Reprogramming of Cancers

As one of novel hallmarks of cancer, lipid metabolic reprogramming has recently been becoming fascinating and widely studied. Lipid metabolic reprogramming in cancer is shown to support carcinogenesis, progression, distal metastasis, and chemotherapy resistance by generating ATP, biosynthesizing macromolecules, and maintaining appropriate redox status. Notably, increasing evidence confirms that lipid metabolic reprogramming is under the control of dysregulated non-coding RNAs in cancer, especially lncRNAs and circRNAs. This review highlights the present research findings on the aberrantly expressed lncRNAs and circRNAs involved in the lipid metabolic reprogramming of cancer. Emphasis is placed on their regulatory targets in lipid metabolic reprogramming and associated mechanisms, including the clinical relevance in cancer through lipid metabolism modulation. Such insights will be pivotal in identifying new theranostic targets and treatment strategies for cancer patients afflicted with lipid metabolic reprogramming.

Autophagy/ferroptosis in colorectal cancer: Carcinogenic view and nanoparticle-mediated cell death regulation

The cell death mechanisms have a long history of being evaluated in diseases and pathological events. The ability of triggering cell death is considered to be a promising strategy in cancer therapy, but some mechanisms have dual functions in cancer, requiring more elucidation of underlying factors. Colorectal cancer (CRC) is a disease and malignant condition of colon and rectal that causes high mortality and morbidity. The autophagy targeting in CRC is therapeutic importance and this cell death mechanism can interact with apoptosis in inhibiting or increasing apoptosis. Autophagy has interaction with ferroptosis as another cell death pathway in CRC and can accelerate ferroptosis in suppressing growth and invasion. The dysregulation of autophagy affects the drug resistance in CRC and pro-survival autophagy can induce drug resistance. Therefore, inhibition of protective autophagy enhances chemosensitivity in CRC cells. Moreover, autophagy displays interaction with metastasis and EMT as a potent regulator of invasion in CRC cells. The same is true for ferroptosis, but the difference is that function of ferroptosis is determined and it can reduce viability. The lack of ferroptosis can cause development of chemoresistance in CRC cells and this cell death mechanism is regulated by various pathways and mechanisms that autophagy is among them. Therefore, current review paper provides a state-of-art analysis of autophagy, ferroptosis and their crosstalk in CRC. The nanoparticle-mediated regulation of cell death mechanisms in CRC causes changes in progression. The stimulation of ferroptosis and control of autophagy (induction or inhibition) by nanoparticles can impair CRC progression. The engineering part of nanoparticle synthesis to control autophagy and ferroptosis in CRC still requires more attention.

Research progress on the biological basis of Traditional Chinese Medicine syndromes of gastrointestinal cancers

Gastrointestinal cancers account for 11.6 % of all cancers, and are the second most frequently diagnosed type of cancer worldwide. Traditional Chinese medicine (TCM), together with Western medicine or alone, has unique advantages for the prevention and treatment of cancers, including gastrointestinal cancers. Syndrome differentiation and treatment are basic characteristics of the theoretical system of TCM. TCM syndromes are the result of the differentiation of the syndrome and the basis of treatment. Genomics, transcriptomics, proteomics, metabolomics, intestinal microbiota, and serology, generated around the central law, are used to study the biological basis of TCM syndromes in gastrointestinal cancers. This review summarizes current research on the biological basis of TCM syndrome in gastrointestinal cancers and provides useful references for future research on TCM syndrome in gastrointestinal cancers.

ZEB1-mediated biogenesis of circNIPBL sustains the metastasis of bladder cancer via Wnt/β-catenin pathway

BACKGROUND

Circular RNAs (circRNAs) circularized by back-splicing of pre-mRNA are widely expressed and affected the proliferation, invasion and metastasis of bladder cancer (BCa). However, the mechanism underlying circRNA biogenesis in mediating the distant metastasis of BCa still unexplored.

METHODS

RNA sequencing data between BCa and normal adjacent tissues was applied to identify the differentially expressed circRNAs. The functions of circNIPBL in BCa were investigated via a series of biochemical experiments. The Clinical significance of circNIPBL was examined in a cohort of larger BCa tissues.

RESULTS

In the present study, we identified a novel circRNA (hsa_circ_0001472), circNIPBL, which was significantly upregulated and had great influence on the poor prognosis of patients with BCa. Functionally, circNIPBL promotes BCa metastasis in vitro and in vivo. Mechanistically, circNIPBL upregulate the expression of Wnt5a and activated the Wnt/β-catenin signaling pathway via directly sponged miR-16-2-3p, leading to the upregulation of ZEB1, which triggers the EMT of BCa. Moreover, we revealed that ZEB1 interacted with the flanking introns of exons 2-9 on NIPBL pre-mRNA to trigger circNIPBL biogenesis, thus forming a positive feedback loop. Importantly, circNIPBL overexpression significantly facilitated the distant metastasis of BCa in the orthotopic bladder cancer model, while silencing ZEB1 remarkably blocked the effects of metastasis induced by circNIPBL overexpression.

CONCLUSIONS

Our study highlights that circNIPBL-induced Wnt signaling pathway activation triggers ZEB1-mediated circNIPBL biogenesis, which forms a positive feedback loop via the circNIPBL/miR-16-2-3p/Wnt5a/ZEB1 axis, supporting circNIPBL as a novel therapeutic target and potential biomarker for BCa patients.

Activation of ACLY by SEC63 deploys metabolic reprogramming to facilitate hepatocellular carcinoma metastasis upon endoplasmic reticulum stress

BACKGROUND

Tumor cells display augmented capability to maintain endoplasmic reticulum (ER) homeostasis and hijack ER stress pathway for malignant phenotypes under microenvironmental stimuli. Metabolic reprogramming is a well-known hallmark for tumor cells to provide specific adaptive traits to the microenvironmental alterations. However, it's unknown how tumor cells orchestrate metabolic reprogramming and tumor progression in response to ER stress. Herein, we aimed to explore the pivotal roles of SEC63-mediated metabolic remodeling in hepatocellular carcinoma (HCC) cell metastasis after ER stress.

METHODS

The expression levels of SEC63 in HCC tissues and adjacent non-cancerous tissues were determined by immunohistochemistry and western blot. The regulatory roles of SEC63 in HCC metastasis were investigated both in vitro and in vivo by RNA-sequencing, metabolites detection, immunofluorescence, and transwell migration/invasion analyses. GST pull-down, immunoprecipitation/mass spectrometry and in vivo ubiquitination/phosphorylation assay were conducted to elucidate the underlying molecular mechanisms.

RESULTS

We identified SEC63 as a new regulator of HCC cell metabolism. Upon ER stress, the phosphorylation of SEC63 at T537 by IRE1α pathway contributed to SEC63 activation. Then, the stability of ACLY was upregulated by SEC63 to increase the supply of acetyl-CoA and lipid biosynthesis, which are beneficial for improving ER capacity. Meanwhile, SEC63 also entered into nucleus for increasing nuclear acetyl-CoA production to upregulate unfolded protein response targets to improve ER homeostasis. Importantly, SEC63 coordinated with ACLY to epigenetically modulate expression of Snail1 in the nucleus. Consequently, SEC63 promoted HCC cell metastasis and these effects were reversed by ACLY inhibition. Clinically, SEC63 expression was significantly upregulated in HCC tissue specimens and was positively correlated with ACLY expression. Importantly, high expression of SEC63 predicted unfavorable prognosis of HCC patients.

CONCLUSIONS

Our findings revealed that SEC63-mediated metabolic reprogramming plays important roles in keeping ER homeostasis upon stimuli in HCC cells. Meanwhile, SEC63 coordinates with ACLY to upregulate the expression of Snail1, which further promotes HCC metastasis. Metastasis is crucial for helping cancer cells seek new settlements upon microenvironmental stimuli. Taken together, our findings highlight a cancer selective adaption to ER stress as well as reveal the potential roles of the IRE1α-SEC63-ACLY axis in HCC treatment.