LncRNA XIST/miR-137 axis strengthens chemo-resistance and glycolysis of colorectal cancer cells by hindering transformation from PKM2 to PKM1

Unraveling the role of long non-coding RNAs in therapeutic resistance in acute myeloid leukemia: New prospects & challenges

Acute Myeloid Leukemia (AML) is a fatal hematological disease characterized by the unchecked proliferation of immature myeloid blasts in different tissues developed by various mutations in hematopoiesis. Despite intense chemotherapeutic regimens, patients often experience poor outcomes, leading to substandard remission rates. In recent years, long non-coding RNAs (lncRNAs) have increasingly become important prognostic and therapeutic hotspots, due to their contributions to dysregulating many functional epigenetic, transcriptional, and post-translational mechanisms leading to alterations in cell expressions, resulting in increased chemoresistance and reduced apoptosis in leukemic cells. Through this review, I highlight and discuss the latest advances in understanding the major mechanisms through which lncRNAs confer therapy resistance in AML. In addition, I also provide perspective on the current strategies to target lncRNA expressions. A better knowledge of the critical role that lncRNAs play in controlling treatment outcomes in AML will help improve existing medications and devise new ones.

Emerging roles of long noncoding RNAs in enzymes related intracellular metabolic pathways in cancer biology

Metabolic reprogramming plays critical roles in the development and progression of tumor by providing cancer cells with a sufficient supply of nutrients and other factors needed for fast-proliferating. Emerging evidence indicates that long noncoding RNAs (lncRNAs) are involved in the initiation of metastasis via regulating the metabolic reprogramming in various cancers. In this paper, we aim to summarize that lncRNAs could participate in intracellular nutrient metabolism including glucose, amino acid, lipid, and nucleotide, regardless of whether lncRNAs have tumor-promoting or tumor-suppressor function. Meanwhile, modulation of lncRNAs in glucose metabolic enzymes in glycolysis, pentose phosphate pathway and tricarboxylic acid cycle (TCA) in cancer is reviewed. We also discuss therapeutic strategies targeted at interfering with enzyme activity to decrease the utilization of glucoses, amino acid, nucleotide acid and lipid in tumor cells. This review focuses on our current understanding of lncRNAs participating in cancer cell metabolic reprogramming, paving the way for further investigation into the combination of such approaches with existing anti-cancer therapies.

LncRNA XIST Protects Against Polycystic Ovary Syndrome via the Regulation of miR-212-3p/RASA1 Axis

The polycystic ovary syndrome (PCOS), a common endocrine disorder, is mainly related to infertility. Moreover, it is characterized by promoted androgen, suppressed ovulation and insulin resistance. Long non-coding RNA X inactive specific transcript (lncRNA XIST), known as an oncogene or a cancer inhabited factor, is involved in several disease. However, the diagnostic mechanisms of lncRNA XIST in PCOS have not been clarified. Our study aimed to explain whether lncRNA XIST regulates KGN cells proliferation and apoptosis via microRNA (miR)-212-3p/RASA1 axis in PCOS. Levels of lncRNA XIST, miR-212-3p and RASA1 in KGN cells were detected through reverse transcription quantitative polymerase chain reaction (RT-qPCR) assay. Fluorescence in situ Hybridization (FISH) was performed to confirm the expression of lncRNA XIST and miR-212-3p in KGN cells. StarBase and dual-luciferase reporter assay were applied for exploring the interaction between miR-212-3p and RASA1. Cell viability, apoptosis, protein expression of Bcl-2 and Bax were assessed by MTT, flow cytometry analysis, RT-qPCR and western blot, respectively. We found that lncRNA XIST was low-expressed, miR-212-3p was over-expressed, and RASA1 was dramatically down-regulated in KGN cells. LncRNA XIST negatively regulated miR-212-3p expression in KGN cells. MiR-212-3p interacted with RASA1 and negatively regulated RASA1 levels in KGN cells. Up-regulation of lncRNA XIST signally decreased cells viability, stimulated more apoptotic cells, enhanced Bax expression, and depressed Bcl-2 level in KGN cells. However, these observations were abolished after miR-212-3p mimic treatment. Furthermore, miR-212-3p inhibitor significantly inhibited cell proliferation, enhanced more apoptotic cells, increased Bax expression, and decreased Bcl-2 level in KGN cells, and these effects were eliminated by RASA1-siRNA transfection. Our observations revealed that lncRNA XIST protects against PCOS through regulating miR-212-3p/RASA1 axis, suggesting that lncRNA XIST may be a promising therapeutic target for PCOS therapy.

LncRNA XIST promotes bladder cancer progression by modulating miR-129-5p/TNFSF10 axis

BACKGROUND

The differential expression, biological function, and ceRNA regulatory mechanism of lncRNA XIST in bladder cancer (BC) were investigated, and its clinical values for the early diagnosis of bladder cancer patients were elucidated.

METHODS

qRT-PCR was employed to detect the expression patterns of lncRNA XIST, miR-129-5p and TNFSF10. The biological functions were measured by CCK8 assay, wound healing assay and transwell assay. Bioinformatics analysis and Dual-Luciferase reporter assay were employed to evaluate the interactions between the lncRNA XIST, miR-129-5p and TNFSF10.

RESULTS

LncRNA XIST and TNFSF10 were highly expressed and miR-129-5p was low expressed (P < 0.05) in bladder cancer cell line. The depletion of lncRNA XIST inhibited BC proliferation, migration and invasion. Mechanistically, lncRNA XIST could sponge miR-129-5p to regulate TNFSF10 expression in bladder cancer. Furthermore, compared with adjacent tissues, lncRNA XIST and miR-129-5p were lowly expressed (P < 0.01) in bladder cancer tissues, and TNFSF10 was highly expressed (P < 0.001). miR-129-5p and TNFSF10 were associated with the risk of bladder cancer (P < 0.05); the difference in AUC values for the diagnosis of bladder cancer by lncRNA XIST (AUC = 0.739), miR-129-5p (AUC = 0.850) and TNFSF10 (AUC = 0.753) was statistically significant (P < 0.01), and the three genes combined AUC was 0.900, 95%CI was 0.842-0.958 with a sensitivity of 83.3% and specificity of 86.7%.

CONCLUSION

XIST, an elevated lncRNA in bladder cancer, inhibition of which could suppress the progression of BC. LncRNA XIST and miR-129-5p could form ceRNA to regulate the expression of TNFSF10.

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.

Targeted splicing therapy: new strategies for colorectal cancer

RNA splicing is the process of forming mature mRNA, which is an essential phase necessary for gene expression and controls many aspects of cell proliferation, survival, and differentiation. Abnormal gene-splicing events are closely related to the development of tumors, and the generation of oncogenic isoform in splicing can promote tumor progression. As a main process of tumor-specific splicing variants, alternative splicing (AS) can promote tumor progression by increasing the production of oncogenic splicing isoforms and/or reducing the production of normal splicing isoforms. This is the focus of current research on the regulation of aberrant tumor splicing. So far, AS has been found to be associated with various aspects of tumor biology, including cell proliferation and invasion, resistance to apoptosis, and sensitivity to different chemotherapeutic drugs. This article will review the abnormal splicing events in colorectal cancer (CRC), especially the tumor-associated splicing variants arising from AS, aiming to offer an insight into CRC-targeted splicing therapy.

Long noncoding RNAs, glucose metabolism and cancer (Review)

Cancer is a serious and potentially life-threatening disease, which, despite numerous advances over several decades, remains a challenge to treat that challenging to detect at an early stage or treat during the later stages. Long noncoding RNAs are >200 nucleotides long and do not possess protein-coding capacity, instead regulating cellular processes, such as proliferation, differentiation, maturation, apoptosis, metastasis, and sugar metabolism. Several studies have shown the role of lncRNAs and glucose metabolism in regulating several key glycolytic enzymes and the activity of multiple functional signaling pathways during tumor progression. Thus, it is possible to further learn about the effects of lncRNA and glycolytic metabolism on tumor diagnosis, treatment, and prognosis through a thorough investigation of the lncRNA expression profiles and glycolytic metabolism in tumors. This may provide a novel strategy for improving the management of several types of cancer.

Molecular profile of non-coding RNA-mediated glycolysis control in human cancers

The glycolysis is a common characteristic of cancer and it is responsible for providing enough energy to ensure growth. The glycolysis suppression is beneficial in tumor growth reduction. The stimulation/inhibition of glycolysis in cancer is tightly regulated by ncRNAs. The regulation of glycolysis by ncRNAs can influence proliferation and therapy response of tumor. The miRNAs are capable of inactivating enzymes responsible for glycolysis and suppressing signaling networks resulting in glycolysis induction. By regulation of glycolysis, miRNAs can affect therapy response. The lncRNAs and circRNAs follow a same pathway and by targeting glycolysis, they affect progression and therapy response of tumor. Noteworthy, lncRNAs and circRNAs sponge miRNAs in glycolysis mechanism control in tumor cells. Furthermore, ncRNA-mediated regulation of glycolysis mechanism can influence metastasis to organs of body. The ncRNAs regulating glycolysis are reliable biomarkers in cancer patients and more importantly, exosomal ncRNAs due to their presence in body fluids, are minimally-invasive biomarkers.

Recent advances microRNAs and metabolic reprogramming in colorectal cancer research

Colorectal cancer (CRC) is a cancer with the highest incidence and mortality. Alteration of gene expression is the main pathophysiological mechanism of CRC, which results in disturbed signaling pathways and cellular metabolic processes. MicroRNAs are involved in almost all pathophysiological processes and are correlative with colorectal cancer metabolism, proliferation, and chemotherapy resistance. Metabolic reprogramming, an important feature of cancer, is strongly correlative with the development and prognosis of cancers, including colorectal cancer. MicroRNAs can target enzymes involved in metabolic processes, thus playing a regulatory role in tumor metabolism. The disorder of the signaling pathway is another characteristic of tumor, which induces the occurrence and proliferation of tumors, and is closely correlative with the prognosis and chemotherapy resistance of tumor patients. MicroRNAs can target the components of the signaling pathways to regulate their transduction. Understanding the function of microRNAs in the occurrence and proliferation of CRC provides novel insights into the optimal treatment strategies, prognosis, and development of diagnosis in CRC. This article reviews the relationship between CRC and microRNA expression and hopes to provide new options for the diagnosis and treatment of CRC.

Potential roles of lncRNA-XIST/miRNAs/mRNAs in human cancer cells

Long non-coding RNAs (lncRNAs) are non-coding RNAs that contain more than 200 nucleotides but do not code for proteins. In tumorigenesis, lncRNAs can have both oncogenic and tumor-suppressive properties. X inactive-specific transcript (XIST) is a known lncRNA that has been implicated in X chromosome silencing in female cells. Dysregulation of XIST is associated with an increased risk of various cancers. Therefore, XIST can be a beneficial prognostic biomarker for human malignancies. In this review, we attempt to summarize the emerging roles of XIST in human cancers.

The cuproptosis related genes signature predicts the prognosis and correlates with the immune status of clear cell renal cell carcinoma

Background: Clear cell renal cell carcinoma (CCRCC) has a high incidence and poor prognosis. Cuproptosis, an independent pattern of cell death associated with copper, plays an important role in cancer proliferation and metastasis. The role of cuproptosis-related genes (CRGs) in CCRCC is unclear.

Methods: Transcriptome and clinical information for CCRCC were downloaded from The Cancer Genome Atlas (TCGA) database. After dividing the training and testing cohort, a 4-CRGs risk signature (FDX1, DLD, DLAT, CDKN2A) was identified in the training cohort using Least absolute shrinkage and selection operator (LASSO) and Cox regression analysis. The effect of the 4-CRGs risk signature on prognosis was assessed using Kaplan-Meier (KM) curves and time-dependent receiver operating characteristic (ROC) curves and verified using the testing cohort. For different risk groups, the immune statue was assessed using the CIBERSORT algorithm, the ssGSEA method and immune checkpoint expression data. Finally, a competitive endogenous RNA (ceRNA) network was constructed using miRTarbase and starBase databases to identify molecules that may have a regulatory relationship with CRCCC.

Results: There were significant changes in the overall survival (OS), immune microenvironment, immune function, and checkpoint gene expression among the different risk groups. A ceRNA network consisting of one mRNA, two miRNAs, and 12 lncRNAs was constructed.

Conclusion: The 4-CRGs risk signature provides a new method to predict the prognosis of patients with CCRCC and the effect of immunotherapy. We propose a new cuproptosis-associated ceRNA network that can help to further explore the molecular mechanisms of CCRCC.

Recent advances in the diagnostic and therapeutic roles of microRNAs in colorectal cancer progression and metastasis

Colorectal cancer (CRC) is the third most common malignancy in the world and one of the leading causes of cancer death; its incidence is still increasing in most countries. The early diagnostic accuracy of CRC is low, and the metastasis rate is high, resulting in a low survival rate of advanced patients. MicroRNAs (miRNAs) are a small class of noncoding RNAs that can inhibit mRNA translation and trigger mRNA degradation, and can affect a variety of cellular and molecular targets. Numerous studies have shown that miRNAs are related to tumour progression, immune system activity, anticancer drug resistance, and the tumour microenvironment. Dysregulation of miRNAs occurs in a variety of malignancies, including CRC. In this review, we summarize the recent research progress of miRNAs, their roles in tumour progression and metastasis, and their clinical value as potential biomarkers or therapeutic targets for CRC. Furthermore, we combined the roles of miRNAs in tumorigenesis and development with the therapeutic strategies of CRC patients, which will provide new ideas for the diagnosis and treatment of CRC.

Emerging role of non-coding RNAs in glucose metabolic reprogramming and chemoresistance in colorectal cancer

Metabolic reprogramming plays a critical role in colorectal cancer (CRC). It contributes to CRC by shaping metabolic phenotypes and causing uncontrolled proliferation of CRC cells. Glucose metabolic reprogramming is common in carcinogenesis and cancer progression. Growing evidence has implicated the modifying effects of non-coding RNAs (ncRNAs) in glucose metabolic reprogramming and chemoresistance in CRC. In this review, we have summarized currently published studies investigating the role of ncRNAs in glucose metabolic alterations and chemoresistance in CRC. Elucidating the interplay between ncRNAs and glucose metabolic reprogramming provides insight into exploring novel biomarkers for the diagnosis and prognosis prediction of CRC.

Molecular mechanism, regulation, and therapeutic targeting of the STAT3 signaling pathway in esophageal cancer (Review)

Esophageal cancer (EC) is the seventh most common cancer globally, and the overall 5-year survival rate is only 20%. Signal transducer and activator of transcription 3 (STAT3) is aberrantly activated in EC, and its activation is associated with a poor prognosis. STAT3 can be activated by canonical pathways such as the JAK/STAT3 pathway as well as non-canonical pathways including the Wnt/STAT3 and COX2/PGE2/STAT3 pathways. Activated STAT3, present as phosphorylated STAT3 (p-STAT3), can be transported into the nucleus to regulate downstream genes, including VEGF, cyclin D1, Bcl-xL, and matrix metalloproteinases (MMPs), to promote cancer cell proliferation and induce resistance to therapy. Non-coding RNAs, including microRNAs (miRNAs/miRs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs), play a vital role in regulating the STAT3 signaling pathway in EC. Several miRNAs promote or suppress the function of STAT3 in EC, while lncRNAs and circRNAs primarily promote the effects of STAT3 and the progression of cancer. Additionally, various drugs and natural compounds can target STAT3 to suppress the malignant behavior of EC cells, providing novel insights into potential EC therapies.

Contribution of MicroRNAs in Chemoresistance to Cisplatin in the Top Five Deadliest Cancer: An Updated Review

Cisplatin (DDP) is a well-known anticancer drug used for the treatment of numerous human cancers in solid organs, including bladder, breast, cervical, head and neck squamous cell, ovarian, among others. Its most important mode of action is the DNA-platinum adducts formation, inducing DNA damage response, silencing or activating several genes to induce apoptosis; these mechanisms result in genetics and epigenetics modifications. The ability of DDP to induce tumor cell death is often challenged by the presence of anti-apoptotic regulators, leading to chemoresistance, wherein many patients who have or will develop DDP-resistance. Cancer cells resist the apoptotic effect of chemotherapy, being a problem that severely restricts the successful results of treatment for many human cancers. In the last 30 years, researchers have discovered there are several types of RNAs, and among the most important are non-coding RNAs (ncRNAs), a class of RNAs that are not involved in protein production, but they are implicated in gene expression regulation, and representing the 98% of the human genome non-translated. Some ncRNAs of great interest are long ncRNAs, circular RNAs, and microRNAs (miRs). Accumulating studies reveal that aberrant miRs expression can affect the development of chemotherapy drug resistance, by modulating the expression of relevant target proteins. Thus, identifying molecular mechanisms underlying chemoresistance development is fundamental for setting strategies to improve the prognosis of patients with different types of cancer. Therefore, this review aimed to identify and summarize miRs that modulate chemoresistance in DDP-resistant in the top five deadliest cancer, both in vitro and in vivo human models.

Long non-coding RNA XIST: a novel oncogene in multiple cancers

Long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) is an important lncRNA derived from the XIST gene in mammals. XIST is abnormally expressed in numerous tumors, in most of which XIST functions as an oncogene. XIST is involved in multiple aspects of carcinogenesis, including tumor onset, progression, and prognosis. In our review, we collected and analyzed the recent studies on the impact of XIST in human tumor development. The multilevel molecular functions of XIST in human tumors are comprehensively reviewed to clarify the pathologic mechanisms and to offer a novel direction for further study.

Long non-coding RNA CRNDE exacerbates NPC advancement mediated by the miR-545-5p/CCND2 axis

BACKGROUND

Previous studies indicated CRNDE to have a pivotal part within tumorigenesis. Notwithstanding, precise details on CRNDE activities within NPC are still uncertain. The investigation described in this article served to focus in greater depth on the mechanistics regarding CRNDE, together with all associated regulatory networks, on nasopharyngeal carcinoma (NPC) and its treatment possibilities.

METHODS

Quantitative real-time polymerase chain reaction (RT-qPCR) analyzed CRNDE, miR-545-5p and CCND2 expression within NPCs and representative cell lineages. CCK-8 cell counting-, EdU-, wound-healing-/transwell-assays analyzed cellular proliferation, migrative, together with invasive properties. Apoptosis/cell cycle progression were scrutinized through flow cytometry. Dual-luciferase reporter assays validated CRNDE/miR-545-5p/CCND2 interplay. Proteomic expression of apoptosis-related protein, EMT-related protein and CCND2 protein were evaluated through Western blotting. In addition, Ki67 expression was evaluated through immunohistochemical staining. The effect of CRNDE in vivo was assessed by nude murine xenograft model studies.

RESULTS

This study demonstrated up-regulated expression of CRNDE and CCND2 within NPC tissues/cell lines. Meanwhile, miR-545-5p was down-regulated. CRNDE knock-down or miR-545-5p over-expression drastically reduced NPC proliferative, migrative and invasive properties, promoted apoptosis/altered cell cycle, and inhibited CCND2 expression. However, miR-545-5p down-regulation had opposing effects. All inhibiting functions generated by CRNDE down-regulation upon NPC progression could be counterbalanced or synergistically exacerbated, depending on miR-545-5p down-regulation or up-regulation, respectively. Multiple-level investigations revealed CRNDE to serve as a sponge for miR-545-5p, and can target CCND2 within NPCs.

CONCLUSIONS

CRNDE increases CCND2 expression by competitive binding with miR-545-5p, thus accelerating the development of NPC. This provides potential therapeutic targets and prognostic markers against NPC.

Circular RNA: A promising new star for the diagnosis and treatment of colorectal cancer

Background

Colorectal cancer (CRC) is one of the most common malignant tumors of the digestive tract. According to the research of circular RNAs in the CRC field, compared with linear RNAs, circular RNAs are a special type of noncoding RNA that are covalently closed circular structures, which have no 5' cap structure and 3' polyA tail and are not affected by RNA exonuclease and actinomycin D.

Biological functions

Notably, circular RNAs have a high degree of stability and potential effect on gene regulation. Meanwhile, circular RNAs are involved in the sponge action of microRNAs and mediate protein translation and direct binding, alternative splicing, and histone modification.

Relationships with CRC

Studies have shown that circular RNAs are related to the proliferation, invasion, recurrence, metastasis, ferroptosis, apoptosis, and chemotherapy resistance of CRC.

Conclusions

This article provides a brief review based on the source, structural characteristics, mechanisms, biological functions of circular RNAs, and the relationships between CRC.

Inhibition of the cell migration, invasion and chemoresistance of colorectal cancer cells through targeting KLF3 by miR-365a-3p

Background: Metastasis and chemoresistance limit treatment efficacy of colorectal cancer (CRC) patients. MicroRNAs (miRNAs) have been believed to be candidate biomarkers for tumor cell proliferation, metastasis and chemoresistance, but the related molecular mechanisms are not clear for prognosis prediction.

Aims: We aimed to investigate the role of miR-365a-3p in metastasis and chemoresistance of CRC.

Methods: The expression levels of miR-365a-3p in clinical CRC tissues were analyzed. The effects of miR-365a-3p expression levels on tumor chemoresistance, invasion and migration were also determined. A dual luciferase reporter gene assay was used to determine the effect of miR-365a-3p on its target gene, Kruppel-like factor 3 (KLF3), and the effect of the miR-365a-3p/KLF3 axis on CRC cell chemoresistance, migration and invasion was further investigated.

Results: In patients with CRC with lymph node or distant organ metastasis or in CRC cell lines, the expression levels of miR-365a-3p were significantly downregulated. In addition, the findings of Transwell assays demonstrated that miR-365a-3p significantly suppressed CRC cell migration and invasion. The dual luciferase reporter gene assay results suggested that miR-365a-3p may play an important role in the regulation of migration, invasion and chemoresistance in CRC cells.

Conclusions: The findings of present study provided evidence to suggest that miR-365a-3p may be a potential tumor suppressor gene in CRC and may inhibit the migration, invasion and chemoresistance of CRC cells. These results suggested that targeting miR-365a-3p/KLF3 axis may represent a potential therapeutic intervention for metastatic disease in patients with CRC.

The Mechanism of Warburg Effect-Induced Chemoresistance in Cancer

Although chemotherapy can improve the overall survival and prognosis of cancer patients, chemoresistance remains an obstacle due to the diversity, heterogeneity, and adaptability to environmental alters in clinic. To determine more possibilities for cancer therapy, recent studies have begun to explore changes in the metabolism, especially glycolysis. The Warburg effect is a hallmark of cancer that refers to the preference of cancer cells to metabolize glucose anaerobically rather than aerobically, even under normoxia, which contributes to chemoresistance. However, the association between glycolysis and chemoresistance and molecular mechanisms of glycolysis-induced chemoresistance remains unclear. This review describes the mechanism of glycolysis-induced chemoresistance from the aspects of glycolysis process, signaling pathways, tumor microenvironment, and their interactions. The understanding of how glycolysis induces chemoresistance may provide new molecular targets and concepts for cancer therapy.

Multiple functions of pyruvate kinase M2 in various cell types

Glucose metabolism is a mechanism by which energy is produced in form of adenosine triphosphate (ATP) by mitochondria and precursor metabolites are supplied to enable the ultimate enrichment of mature metabolites in the cell. Recently, glycolytic enzymes have been shown to have unconventional but important functions. Among these enzymes, pyruvate kinase M2 (PKM2) plays several roles including having conventional metabolic enzyme activity, and also being a transcriptional regulator and a protein kinase. Compared with the closely related PKM1, PKM2 is highly expressed in cancer cells and embryos, whereas PKM1 is dominant in mature, differentiated cells. Posttranslational modifications such as phosphorylation and acetylation of PKM2 change its cellular functions. In particular, PKM2 can translocate to the nucleus, where it regulates the transcription of many target genes. It is notable that PKM2 also acts as a protein kinase to phosphorylate several substrate proteins. Besides cancer cells and embryonic cells, astrocytes also highly express PKM2, which is crucial for lactate production via expression of lactate dehydrogenase A (LDHA), while mature neurons predominantly express PKM1. The lactate produced in cancer cells promotes tumor progress and that in astrocytes can be supplied to neurons and may act as a major source for neuronal ATP energy production. Thereby, we propose that PKM2 along with its different posttranslational modifications has specific purposes for a variety of cell types, performing unique functions.

Regulatory Mechanisms of LncRNAs in Cancer Glycolysis: Facts and Perspectives

Cancer cells exhibit distinct metabolic characteristics that employ glycolysis to provide energy and intermediary metabolites. This aberrant metabolic phenotype favors cancer progression. LncRNAs are transcripts longer than 200 nucleotides that do not encode proteins. LncRNAs contribute to cancer progression and therapeutic resistance and affect aerobic glycolysis via multiple mechanisms, including modulating glycolytic transporters and enzymes. Further, dysregulated signaling pathways are vital for glycolysis. In this review, we highlight regulatory mechanisms for lncRNAs in aerobic glycolysis that provide novel insights into cancer development. Moreover, a comprehensive understanding of the regulatory mechanisms of lncRNAs in aerobic glycolysis can provide new strategies for clinical cancer management.

Long noncoding RNA HULC contributes to paclitaxel resistance in ovarian cancer via miR-137/ITGB8 axis

Long noncoding RNA (lncRNA) highly upregulated in liver cancer (HULC) has been reported to be implicated in chemoresistance. However, the potential mechanism of HULC in paclitaxel (PTX)-resistant ovarian cancer (OC) remains undefined. The expression of RNAs and proteins was measured by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and Western blot assay. The PTX resistance and apoptotic rate were assessed via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry, respectively. Furthermore, the interaction between miR-137 and HULC or integrin beta-8 (ITGB8) was predicted by miRcode and starBase v2.0 and then verified by dual luciferase reporter and RNA pull-down assays. In addition, the xenograft mice model was established to explore the effects of HULC in vivo. HULC was significantly upregulated and miR-137 was downregulated in PTX-resistant OC tissues and cells. Also, the HULC depletion suppressed tumor growth and PTX resistance in PTX-treated mice. miR-137 was verified as a target of HULC and directly targeted ITGB8. And HULC knockdown downregulated ITGB8 expression by targeting miR-137. miR-137 inhibitor or ITGB8 overexpression mitigated the suppressive impacts of HULC knockdown on PTX resistance. Collectively, HULC modulated ITGB8 expression to promote PTX resistance of OC by sponging miR-137.

Exosomal IDH1 increases the resistance of colorectal cancer cells to 5-Fluorouracil

Chemoresistance challenges the clinical treatment of colorectal cancer and requires an urgent solution. Isocitrate dehydrogenase 1 (IDH1) is a key enzyme involved in glucose metabolism that mediates the malignant transformation of tumors. However, the mechanisms by which IDH1 is involved in colorectal cancer cell proliferation and drug resistance induction remain unclear. In this study, we found that IDH1 was highly expressed in human colorectal cancer tissues and could be used to indicate a high-grade tumor. In vitro gene overexpression and knockdown were used to determine whether IDH1 promoted the proliferation of the colorectal cancer cell line HCT8 and resistance to 5-Fluorouracil (5FU). Further studies have shown that the 5FU-resistant cell line, HCT8FU, secreted exosomes that contained a high level of IDH1 protein. The exosomal IDH1 derived from 5FU-resistant cells enhanced the resistance of 5FU-sensitive cells. Metabolic assays revealed that exosomes derived from 5FU-resistant cells promoted a decrease in the level of IDH1-mediated NADPH, which is associated with the development of 5FU resistance in colorectal cancer cells. Therefore, exosomal IDH1 may be the transmitter and driver of chemoresistance in colorectal cancer and a potential chemotherapy target.