LDHA Promotes Oral Squamous Cell Carcinoma Progression Through Facilitating Glycolysis and Epithelial-Mesenchymal Transition

Utility of serum and salivary lactate dehydrogenase and uric acid levels as a diagnostic profile in oral squamous cell carcinoma patients

Background

Lactate dehydrogenase (LDH), an intra-cellular enzyme present in all cells of the body, catalyses the final step of anaerobic glycolysis. This intra-cellular enzyme is released into the extra-cellular space after tissue disintegration, which is evident in oral squamous cell carcinoma (OSCC). However, investigations comparing Lactate dehydrogenase (LDH) levels in OSCC and healthy controls have shown conflicting findings in both serum and saliva samples. Further, Uric acid's anti-oxidant activity has been demonstrated in several diseases. Several cancers have been linked to increased uric acid levels. However, uric acid levels in oral squamous cell cancer have varied. There exists limitted research comparing serum and salivary uric acid with OSCC. Thus, the present investigation was conducted to evaluate the combined diagnostic abilities of serum and salivary LDH and uric acid in OSCC.

Aim and Objective

To compare and correlate LDH and uric acid levels in serum and salivary samples of OSCC patients and healthy individuals.

Material and Methods

LDH levels and uric acid levels were measured using an enzymatic method in serum and salivary samples of OSCC cases (n = 18) and healthy individuals (n = 18).

Results

This study indicated statistically significant elevated levels of LDH in serum and saliva samples of OSCC patients when compared to healthy individuals. Furthermore, serum and salivary uric acid were higher in OSCC patients than in controls. This increased levels of uric acid was significant only in serum but not in saliva samples. However, salivary uric acid was found to be co-relating with serum uric acid. In addition to this, the receiver operating characteristic (ROC) curve when plotted to assess combined diagnostic abilities of all the investigations to predict oscc, indicating the diagnostic ability to be 77%.

Conclusion

This study found an increase in uric acid levels in OSCC patients, which contradicts previous existing litratures. Salivary uric acid and LDH levels may be effective indicators for OSCC screening. However, because of the limited sample size, these findings should be viewed with caution.

Expression of Ubiquitin-specific protease 7 in oral squamous cell carcinoma promotes tumor cell proliferation and invasion

Oral Squamous Cell Carcinoma (OSCC) is the most common malignant cancer affecting oral cavity. Recent studies have demonstrated that Ubiquitin-specific protease 7 (USP7) was upregulated in several types of cancers. USP7 expression was associated with various proto-oncogenes and tumor suppressor genes. However, USP7 expression level and its functional role in OSCC is unclear. In the current study, we showed that USP7 expression in OSCC tissues was generally upregulated compared to normal adjacent tissues by using IHC. Furthermore, statistical analysis uncovered that USP7 expression was positively correlated with Ki-67, MMP2, VEGF in OSCC tissues. Importantly, high USP7 expression was significantly correlated with lymph node metastasis and histological differentiation in OSCC patients. So, our hypothesis is that USP7 plays a tumor-promoting role in OSCC. Knocking down of USP7 in tumor cells not only suppressed HSC3 cells proliferation, migration and invasion, but also promoted cell apoptosis. Moreover, USP7 siRNA blocked the activation of Akt/ERK signaling pathway. In conclusion, data presented here suggests that USP7 promotes the progression of OSCC. USP7 may be used as a new therapeutic target for OSCC diagnosis and treatment.

Triple Isozyme Lactic Acid Dehydrogenase Inhibition in Fully Viable MDA-MB-231 Cells Induces Cytostatic Effects That Are Not Reversed by Exogenous Lactic Acid

A number of aggressive human malignant tumors are characterized by an intensified glycolytic rate, over-expression of lactic acid dehydrogenase A (LDHA), and subsequent lactate accumulation, all of which contribute toward an acidic peri-cellular immunosuppressive tumor microenvironment (TME). While recent focus has been directed at how to inhibit LDHA, it is now becoming clear that multiple isozymes of LDH must be simultaneously inhibited in order to fully suppress lactic acid and halt glycolysis. In this work we explore the biochemical and genomic consequences of an applied triple LDH isozyme inhibitor (A, B, and C) (GNE-140) in MDA-MB-231 triple-negative breast cancer cells (TNBC) cells. The findings confirm that GNE-140 does in fact, fully block the production of lactic acid, which also results in a block of glucose utilization and severe impedance of the glycolytic pathway. Without a fully functional glycolytic pathway, breast cancer cells continue to thrive, sustain viability, produce ample energy, and maintain mitochondrial potential (ΔΨ_M). The only observable negative consequence of GNE-140 in this work, was the attenuation of cell division, evident in both 2D and 3D cultures and occurring in fully viable cells. Of important note, the cytostatic effects were not reversed by the addition of exogenous (+) lactic acid. While the effects of GNE-140 on the whole transcriptome were mild (12 up-regulated differential expressed genes (DEGs); 77 down-regulated DEGs) out of the 48,226 evaluated, the down-regulated DEGS collectively centered around a loss of genes related to mitosis, cell cycle, GO/G1–G1/S transition, and DNA replication. These data were also observed with digital florescence cytometry and flow cytometry, both corroborating a G0/G1 phase blockage. In conclusion, the findings in this work suggest there is an unknown element linking LDH enzyme activity to cell cycle progression, and this factor is completely independent of lactic acid. The data also establish that complete inhibition of LDH in cancer cells is not a detriment to cell viability or basic production of energy.

Prognostic model of AU-rich genes predicting the prognosis of lung adenocarcinoma

Background

AU-rich elements (ARE) are vital cis-acting short sequences in the 3’UTR affecting mRNA stability and translation. The deregulation of ARE-mediated pathways can contribute to tumorigenesis and development. Consequently, ARE-genes are promising to predict prognosis of lung adenocarcinoma (LUAD) patients.

Methods

Differentially expressed ARE-genes between LUAD and adjacent tissues in TCGA were investigated by Wilcoxon test. LASSO and Cox regression analyses were performed to identify a prognostic genetic signature. The genetic signature was combined with clinicopathological features to establish a prognostic model. LUAD patients were divided into high- and low-risk groups by the model. Kaplan–Meier curve, Harrell’s concordance index (C-index), calibration curves and decision curve analyses (DCA) were used to assess the model. Function enrichment analysis, immunity and tumor mutation analyses were performed to further explore the underlying molecular mechanisms. GEO data were used for external validation.

Results

Twelve prognostic genes were identified. The gene riskScore, age and stage were independent prognostic factors. The high-risk group had worse overall survival and was less sensitive to chemotherapy and radiotherapy (P < 0.01). C-index and calibration curves showed good performance on survival prediction in both TCGA (1, 3, 5-year ROC: 0.788, 0.776, 0.766) and the GSE13213 validation cohort (1, 3, 5-year ROC: 0.781, 0.811, 0.734). DCA showed the model had notable clinical net benefit. Furthermore, the high-risk group were enriched in cell cycle, DNA damage response, multiple oncological pathways and associated with higher PD-L1 expression, M1 macrophage infiltration. There was no significant difference in tumor mutation burden (TMB) between high- and low-risk groups.

Conclusion

ARE-genes can reliably predict prognosis of LUAD and may become new therapeutic targets for LUAD.

Identification of biomarkers related to glycolysis with weighted gene co-expression network analysis in oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the most common tumor in the oral cavity and maxillofacial region. Increasing evidence suggests that aerobic glycolysis plays an important role in the occurrence, development, and prognosis of OSCC. Therefore, the identification of biomarkers related to glycolysis in OSCC represents considerable potential for improving its treatment.

METHODS

In the present study, a single-sample gene-set enrichment analysis (ssGSEA) algorithm with weighted gene co-expression network analysis (WGCNA) were used to quantify the degree of glycolysis and identify key modules with the greatest correlation with glycolysis.

RESULTS

Glycolytic scores significantly correlated with prognosis. In the key module 5 HUB genes were finally selected, which displayed a robust predictive effect. The expressions of key genes were associated with glycolysis.

CONCLUSIONS

The research comprehensively analyzed the glycolysis of OSCC and identified several biomarkers related to glycolysis. These biomarkers may represent potential therapeutic targets for future OSCC therapy.

Targeting fructose metabolism by glucose transporter 5 regulation in human cholangiocarcinoma

Alterations in cellular metabolism may contribute to tumor proliferation and survival. Upregulation of the facilitative glucose transporter (GLUT) plays a key role in promoting cancer. GLUT5 mediates modulation of fructose utilization, and its overexpression has been associated with poor prognosis in several cancers. However, its metabolic regulation remains poorly understood. Here, we demonstrated elevated GLUT5 expression in human cholangiocarcinoma (CCA), using RNA sequencing data from samples of human tissues and cell lines, as compared to normal liver tissues or a cholangiocyte cell line. Cells exhibiting high-expression of GLUT5 showed increased rates of cell proliferation and ATP production, particularly in a fructose-supplemented medium. In contrast, GLUT5 silencing attenuated cell proliferation, ATP production, cell migration/invasion, and improved epithelial–mesenchymal transition (EMT) balance. Correspondingly, fructose consumption increased tumor growth in a nude mouse xenograft model, and GLUT5 silencing suppressed growth, supporting the tumor-inhibitory effect of GLUT5 downregulation. Furthermore, in the metabolic pathways of fructolysis-Warburg effect, the expression levels of relative downstream genes, including ketohexokinase (KHK), aldolase B (ALDOB), lactate dehydrogenase A (LDHA), and monocarboxylate transporter 4 (MCT4), as well as hypoxia-inducible factor 1 alpha (HIF1A), were altered in a GLUT5 expression-dependent manner. Taken together, these findings indicate that GLUT5 could be a potential target for CCA therapeutic approach via metabolic regulation.

The role of glycometabolic plasticity in cancer

Dysregulated glycometabolism represented by the Warburg effect is well recognized as a hallmark of cancer that can be driven by oncogenes (e.g., c-Myc, K-ras, and BRAF) and contribute to cellular malignant transformation. The Warburg effect reveals the different glycometabolic patterns of cancer cells, but this unique glycometabolic pattern has the characteristic of plasticity rather than changeless which can vary with different internal or external stimuli during evolution. Glycometabolic plasticity enables cancer cells to modulate glycometabolism to support progression, metastasis, treatment resistance and recurrence. In this review, we report the characteristics of glycometabolic plasticity during different stages of cancer evolution, providing insight into the molecular mechanisms of glycometabolic plasticity in cancer. In addition, we discussed the challenges and future research directions of glycometabolism research in cancer.

Long non-coding RNA LINC01207 promotes cell proliferation and migration but suppresses apoptosis and autophagy in oral squamous cell carcinoma by the microRNA-1301-3p/lactate dehydrogenase isoform A axis

Long noncoding RNAs (lncRNAs) have been reported to participate in the progression of various cancers, including oral squamous cell carcinoma (OSCC). This study aims to find out whether lncRNA LINC01207 regulates the progression of OSCC. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was conducted to evaluate gene expression in OSCC cells and tissues. Cell viability, proliferation, migration, apoptosis, and autophagy were detected using Cell Counting Kit-8 (CCK-8), colony formation, Transwell assays, flow cytometry, and western blot analysis. Luciferase reporter and RNA immunoprecipitation (RIP) assays were conducted to assess the interactions among genes. We found that LINC01207 was overexpressed in OSCC cells and tissues. LINC01207 silencing inhibited OSCC cell proliferation and migration but promoted apoptosis and autophagy, and LINC01207 overexpression had an opposite result. LINC01207 interacted with microRNA-1301-3p (miR-1301-3p) while lactate dehydrogenase isoform A (LHDA) was targeted by miR1301-3p. Effects caused by LINC01207 downregulation on OSCC cells were reversed by overexpression of LDHA. Overall, LINC01207 promotes OSCC progression via the miR-1301-3p/LDHA axis

Targeting lncRNA PSMA3-AS1, a Prognostic Marker, Suppresses Malignant Progression of Oral Squamous Cell Carcinoma

Objective

Oral squamous cell carcinoma (OSCC) represents the most common maxillofacial malignancy. This study elucidated the clinicopathological value and molecular mechanisms of PSMA3 antisense RNA 1 (PSMA3-AS1) in OSCC.

Methods

Totally, 135 OSCC patients were recruited. PSMA3-AS1 expression and its prognostic value were assessed in this cohort. si-PSMA3-AS1 was transfected into HN4 and CAL-27 OSCC cells. Then, cell proliferation was evaluated by CCK-8, colony formation, and EdU staining. Migration and invasion were investigated through wound healing, transwell, and western blot. The PSMA3-AS1/miR-136-5p and miR-136-5p/FN1 interactions were validated by dual luciferase report, real-time quantitative polymerase chain reaction (RT-qPCR), and western blot.

Results

PSMA3-AS1 upregulation was determined in OSCC tissues. The upregulation indicated pessimistic patients' outcomes. Multivariate Cox regression analyses confirmed PSMA3-AS1 as an independent prognostic indicator. Its upregulation was also found in OSCC cells. Under transfection with si-PSMA3-AS1, proliferation, migration, and invasion were all restrained in HN4 and CAL-27 OSCC cells. Furthermore, its knockdown induced the increase in E-cadherin expression and the reduction in N-cadherin and Vimentin expression. PSMA3-AS1 was a sponge of miR-136-5p. Mutual inhibition was found between two and the interactions were confirmed by dual luciferase report. It was confirmed that FN1 was a target of miR-136-5p. FN1 expression was increased by miR-136-5p inhibitors, which was lessened by si-PSMA3-AS1 cotransfection.

Conclusion

Collectively, PSMA3-AS1 as a risk factor facilitated malignant behaviors of OSCC cells, related to the miR-136-5p/FN1 axis. Hence, PSMA3-AS1 as a potential therapeutic target for OSCC deserved further exploration.

STAT3/LINC00671 axis regulates papillary thyroid tumor growth and metastasis via LDHA-mediated glycolysis

Lactate dehydrogenase A (LDHA), a critical component of the glycolytic pathway, relates to the development of various cancers, including thyroid cancer. However, the regulatory mechanism of LDHA inhibition and the physiological significance of the LDHA inhibitors in papillary thyroid cancer (PTC) are unknown. Long non-coding RNA (lncRNA) plays a vital role in tumor growth and progression. Here, we identified a novel lncRNA LINC00671 negatively correlated with LDHA, downregulating LDHA expression and predicting good clinical outcome in thyroid cancer. Moreover, hypoxia inhibits LINC00671 expression and activates LDHA expression largely through transcriptional factor STAT3. STAT3/LINC00671/LDHA axis regulates thyroid cancer glycolysis, growth, and lung metastasis both in vitro and in vivo. In thyroid cancer patients, LINC00671 expression is negatively correlated with LDHA and STAT3 expression. Our work established STAT3/LINC00671/LDHA as a critical axis to regulate PTC growth and progression. Inhibition of LDHA or STAT3 or supplement of LINC00671 could be potential therapeutic strategies in thyroid cancer.

Expression and Clinical Significance of Lactate Dehydrogenase A in Colon Adenocarcinoma

Lactate dehydrogenase A (LDHA) is an important glycolytic enzyme that promotes glycolysis and plays a crucial role in cancer cell invasion and immune infiltration. However, the relevance of LDHA in colon adenocarcinoma (COAD) remains unclear. In this study, we analyzed the correlation between the expression of LDHA and clinicopathological characteristics in COAD using immunohistochemistry analysis, and then used integrative bioinformatics analyses to further study the function and role of LDHA in COAD. We found that LDHA was highly expressed in COAD tissues compared with adjacent normal tissues, and that COAD patients with high LDHA expression levels showed poor survival. In addition, LDHA expression was closely associated with the immune infiltrating levels of CD8+ T cells, neutrophils, and dendritic cells. Our findings highlight the potential role of LDHA in the tumorigenesis and prognosis of COAD. Furthermore, our results indicate that COAD is a novel immune checkpoint in the diagnosis and treatment of COAD.

N6-methyladenosine demethyltransferase FTO-mediated autophagy in malignant development of oral squamous cell carcinoma

N6-methyladenosine (m⁶A) is the most abundant internal mRNA modification in eukaryotes and plays an important role in tumorigenesis. However, the underlying mechanism remains largely unclear. Here, we established a cell model of rapamycin-induced autophagy to screen m⁶A-modifying enzymes. We found that m⁶A demethylase fat mass and obesity-associated protein (FTO) plays a key role in regulating autophagy and tumorigenesis by targeting the gene encoding eukaryotic translation initiation factor gamma 1 (eIF4G1) in oral squamous cell carcinoma (OSCC). Knocked down of FTO expression in OSCC cell lines, resulting in downregulation of eIF4G1 along with enhanced autophagic flux and inhibition of tumorigenesis. Rapamycin inhibited FTO activity, and directly targeted eIF4G1 transcripts and mediated their expression in an m⁶A-dependent manner. Dual-luciferase reporter and mutagenesis assays confirmed that YTH N6-methyladenosine RNA-binding protein 2 (YTHDF2) targets eIF4G1. Conclusively, after FTO silencing, YTHDF2 captured eIF4G1 transcripts containing m⁶A, resulting in mRNA degradation and decreased expression of eIF4G1 protein, thereby promoting autophagy and reducing tumor occurrence. Therefore, rapamycin may regulate m⁶A levels, determining the autophagic flux of OSCC, thereby affecting the biological characteristics of cancer cells. This insight expands our understanding of the crosstalk between autophagy and RNA methylation in tumorigenesis, which is essential for therapeutic strategy development for OSCC.

Ras Homolog Family Member F, Filopodia Associated Promotes Hepatocellular Carcinoma Metastasis by Altering the Metabolic Status of Cancer Cells Through RAB3D

BACKGROUND AND AIMS

The mechanism by which tumor cells resist metabolic stress remains unclear, but many oncogenes are known to regulate this process. Accordingly, metabolic stress is closely associated with tumor metastasis. In this study, gene chip technology showed that Ras homolog family member F, filopodia associated (RHOF), a member of the Rho guanosine triphosphatase family, is an oncogene that is significantly related to hepatocellular carcinoma (HCC) metastasis; however, it has rarely been reported in tumors. Our aim was to determine the clinicopathological significance and role of RHOF in HCC progression and investigate the associated mechanisms.

APPROACH AND RESULTS

The results showed that compared to expression in adjacent noncancerous tissues, RHOF was frequently up-regulated in HCC tumor samples and elevated under conditions of glucose deprivation. RHOF expression was associated with tumor-node-metastasis stage, T grade, metastasis status, recurrence, and survival in HCC. RHOF also affected cell morphology and promoted migration, invasion, and epithelial-mesenchymal transition (EMT) of HCC cell lines. Analysis of the underlying mechanism showed that RHOF promoted the Warburg effect by up-regulating the expression and function of several glycolytic enzymes in HCC cells. This metabolic shift enhanced HCC cell migration and invasion. Specifically, RHOF exerted a tumor-promoting effect by directly interacting with AMP-activated protein kinase (AMPK) and increasing the phosphorylation of AMPK. This subsequently affected RAB3D mRNA stability and led to elevated RAB3D expression, thereby amplifying the Warburg effect and malignant biological behaviors of HCC cells.

CONCLUSIONS

RHOF helps tumor cells resist metabolic stress through modulating the Warburg effect and plays a critical role in promoting HCC cell migration, invasion, and EMT, highlighting its important role in remodeling the metastatic microenvironment and regulating tumor metastasis. RHOF shows potential as a therapeutic target and prognostic biomarker for HCC.

The Role of Metabolism in Tumor Immune Evasion: Novel Approaches to Improve Immunotherapy

The tumor microenvironment exhibits altered metabolic properties as a consequence of the needs of tumor cells, the natural selection of the most adapted clones, and the selfish relationship with other cell types. Beyond its role in supporting uncontrolled tumor growth, through energy and building materials obtention, metabolism is a key element controlling tumor immune evasion. Immunotherapy has revolutionized the treatment of cancer, being the first line of treatment for multiple types of malignancies. However, many patients either do not benefit from immunotherapy or eventually relapse. In this review we overview the immunoediting process with a focus on the metabolism-related elements that are responsible for increased immune evasion, either through reduced immunogenicity or increased resistance of tumor cells to the apoptotic action of immune cells. Finally, we describe the main molecules to modulate these immune evasion processes through the control of the metabolic microenvironment as well as their clinical developmental status.

Glycolysis reprogramming in cancer-associated fibroblasts promotes the growth of oral cancer through the lncRNA H19/miR-675-5p/PFKFB3 signaling pathway

As an important component of the tumor microenvironment, cancer-associated fibroblasts (CAFs) secrete energy metabolites to supply energy for tumor progression. Abnormal regulation of long noncoding RNAs (lncRNAs) is thought to contribute to glucose metabolism, but the role of lncRNAs in glycolysis in oral CAFs has not been systematically examined. In the present study, by using RNA sequencing and bioinformatics analysis, we analyzed the lncRNA/mRNA profiles of normal fibroblasts (NFs) derived from normal tissues and CAFs derived from patients with oral squamous cell carcinoma (OSCC). LncRNA H19 was identified as a key lncRNA in oral CAFs and was synchronously upregulated in both oral cancer cell lines and CAFs. Using small interfering RNA (siRNA) strategies, we determined that lncRNA H19 knockdown affected proliferation, migration, and glycolysis in oral CAFs. We found that knockdown of lncRNA H19 by siRNA suppressed the MAPK signaling pathway, 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) and miR-675-5p. Furthermore, the lncRNA H19/miR-675-5p/PFKFB3 axis was involved in promoting the glycolysis pathway in oral CAFs, as demonstrated by a luciferase reporter system assay and treatment with a miRNA-specific inhibitor. Our study presents a new way to understand glucose metabolism in oral CAFs, theoretically providing a novel biomarker for OSCC molecular diagnosis and a new target for antitumor therapy.

PDIA6 contributes to aerobic glycolysis and cancer progression in oral squamous cell carcinoma

Background/objective

Accumulated evidence has demonstrated that aerobic glycolysis serves as a regulator of tumor cell growth, invasion, and angiogenesis. Herein, we explored the role of protein disulfide isomerase family 6 (PDIA6) in the aerobic glycolysis and the progression of oral squamous cell carcinoma (OSCC).

Methods

The expression pattern of PDIA6 in OSCC tissues was determined by qPCR and western blotting. Lentivirus and small interfering RNAs (siRNAs) were introduced into cells to upregulate and downregulate PDIA6 expression. CCK-8, flow cytometry, transwell, and xenotransplantation models were applied to detect cell proliferation, apoptosis, migration, invasion, and tumorigenesis, respectively.

Results

A high expression pattern of PDIA6 was observed in OSCC tissues, which was closely associated with lower overall survival and malignant clinical features in OSCC. Compared with the control group, overexpression of PDIA6 induced significant enhancements in cell growth, migration, invasiveness, and tumorigenesis and decreased cell apoptosis, while knockdown of PDIA6 caused opposite results. In addition, overexpression of PDIA6 increased glucose consumption, lactate production, and ATP level in OSCC cells.

Conclusion

This study demonstrated that PDIA6 expression was elevated in OSCC tissues, and overexpression of it promoted aerobic glycolysis and OSCC progression.

UCHL3 promotes aerobic glycolysis of pancreatic cancer through upregulating LDHA expression

BACKGROUND

Aerobic glycolysis has a pivotal role in the carcinogenic process. The current understanding of the functional role and mechanism of UCHL3-related aerobic glycolysis in pancreatic cancer is far from comprehensive, therefore requires an in-depth analysis on this aspect.

METHODS

In the present research, the expressions of ubiquitin carboxyl-terminal hydrolase L3 (UCHL3), lactate dehydrogenase A (LDHA) and Forkhead box protein M1 (FOXM1) were detected by qRT-PCR, Western blot and immunohistochemistry. The effects of UCHL3 knockdown or overexpression on pancreatic cancer cells were examined by determining cell viability and colony formation. Aerobic glycolysis was assessed according to glucose uptake, lactic acid production, and lactate dehydrogenase (LDH) activity. Dual-luciferase reporter assay was performed to detect LDHA promoter activity.

RESULTS

The results showed that UCHL3 expression was significantly increased in the pancreatic cancer tissues and cells, and that knocking down UCHL3 noticeably inhibited cell viability and aerobic glycolysis. Further investigations revealed that LDHA expression was promoted by UCHL3 and could be reduced by shFOXM1, and that low-expressed LDHA partly reversed the inhibition of aerobic glycolysis induced by overexpressed UCHL3.

CONCLUSIONS

To conclude, this study demonstrates that UCHL3 plays a carcinogenic role by promoting aerobic glycolysis in pancreatic cancer, suggesting that UCHL3 may be a potential diagnostic and therapeutic target for the treatment of cancer.

A Novel Glycolysis-Related Four-mRNA Signature for Predicting the Survival of Patients With Breast Cancer

Background: Glycolysis is critical in the occurrence and development of tumors. Owing to the biological and clinical heterogeneity of patients with BRCA, the traditional predictive classification system is far from satisfactory. Survival and prognosis biomarkers related to glycolysis have broad application prospects for assessing the risk of patients and guiding their individualized treatment.

Methods: The mRNA expression profiles and clinical information of patients with BRCA were obtained from TCGA database, and glycolysis-related genes were obtained by GSEA. Patients with BRCA were randomly divided into the training cohort and testing cohort. Univariate and multivariate Cox analyses were used to establish and validate a new mRNA signature for predicting the prognosis of patients with BRCA.

Results: We established a four-gene breast cancer prediction signature that included PGK1, SDHC, PFKL, and NUP43. The patients with BRCA in the training cohort and testing cohort were divided into high-risk and low-risk groups based on the signature. The AUC values were 0.74 (training cohort), 0.806 (testing cohort) and 0.769 (entire cohort), thereby showing that the prediction performance of the signature is acceptable. Additionally, Cox regression analysis revealed that four-gene signature could independently predict the prognosis of BRCA patients without being affected by clinical factors.

Conclusion: We constructed a four-gene signature to predict the prognosis of patients with BRCA. This signature will aid in the early diagnosis and personalized treatment of breast cancer, but the specific associated biological mechanism requires further study.

Lactate Metabolism in Breast Cancer Microenvironment: Contribution Focused on Associated Adipose Tissue and Obesity

Metabolic reprogramming that favors high glycolytic flux with lactate production in normoxia is among cancer hallmarks. Lactate is an essential oncometabolite regulating cellular redox homeostasis, energy substrate partitioning, and intracellular signaling. Moreover, malignant phenotype's chief characteristics are dependent on the interaction between cancer cells and their microenvironment. In breast cancer, mammary adipocytes represent an essential cellular component of the tumor milieu. We analyzed lactate concentration, lactate dehydrogenase (LDH) activity, and isozyme pattern, and LDHA/LDHB protein expression and tissue localization in paired biopsies of breast cancer tissue and cancer-associated adipose tissue in normal-weight and overweight/obese premenopausal women, compared to benign breast tumor tissue and adipose tissue in normal-weight and overweight/obese premenopausal women. We show that higher lactate concentration in cancer tissue is concomitant with a shift in isozyme pattern towards the "muscle-type" LDH and corresponding LDHA and LDHB protein expression changes. In contrast, significantly higher LDH activity in cancer-associated adipose tissue seems to be directed towards lactate oxidation. Moreover, localization patterns of LDH isoforms varied substantially across different areas of breast cancer tissue. Invasive front of the tumor showed cell-specific protein localization of LDHA in breast cancer cells and LDHB in cancer-associated adipocytes. The results suggest a specific, lactate-centric relationship between cancer tissue and cancer-associated adipose tissue and indicate how cancer-adipose tissue cross-talk may be influenced by obesity in premenopausal women.

Effect of lactate as a peritoneal dialysis fluid buffer on rat peritoneal mesothelial cells

Background

Neutral, low-glucose degradation product (GDP) peritoneal dialysis fluid (PDF) is less damaging to the peritoneum than conventional PDF but is still insufficient for biocompatibility. One remaining issue is the problem of buffering.

Methods

Using cultured rat peritoneal mesothelial cells (PMCs), the present study examined the difference between the effects of neutral low-GDP lactate PDF and neutral low-GDP bicarbonate/lactate PDF on cells. The effects of lactate stimulation on these cells were also examined.

Results

Lactate PDF enhanced mRNA expressions of α-smooth muscle actin (αSMA) and type 1 and type 3 collagens and lowered expression of e-cadherin mRNA in PMCs compared to bicarbonate/lactate PDF. Lactate stimulation increased mRNA expressions of αSMA, matrix metalloproteinase 2 (MMP2), and basic fibroblast growth factor (bFGF) and suppressed e-cadherin mRNA expression. Transforming growth factor (TGF)-β1 and TGF-β2 and collagen type 1 and 3 mRNA expressions were also enhanced by lactate stimulation.

Conclusions

These results suggest that lactate as a PDF buffer may act on PMCs to promote epithelial-mesenchymal transition (EMT) and production of TGF-β, bFGF, and collagen.

Long non-coding RNA FOXD1-AS1 promotes the progression and glycolysis of nasopharyngeal carcinoma by sustaining FOXD1 expression

Long non-coding RNAs (lncRNAs) play a vital role in the progression of several cancers, including nasopharyngeal carcinoma (NPC). However, the mechanism of lncRNA involvement in the progression of NPC remains to be elucidated. Hence, we conducted in vivo and in vitro experiments to determine the molecular mechanism of FOXD1-AS1. We found that FOXD1-AS1 was over-expressed in NPC cells and tissues, and was significantly associated with poor survival rate in patients with NPC. We also found that FOXD1-AS1 promotes cellular proliferation, migration, invasion, and glycolysis, and inhibits apoptosis by upregulating the expression of FOXD1. Furthermore, FOXD1 could transcriptionally up-regulate the expression of key glycolytic genes to promote the glycolysis levels of NPC. The identified FOXD1-AS1 may serve as a potential prognostic biomarker and therapeutic target for patients with NPC.

Lactate dehydrogenase A inhibition by small molecular entities: steps in the right direction

Direct targeting of energy metabolism to defeat cancer is not a recent strategy. Although quite a few drugs use cellular metabolism for their antitumor effect, no direct inhibitors of energy metabolism have been approved by the FDA. Currently, several inhibitors of lactate dehydrogenase A (LDH-A), a key player in glycolysis, are in development. Earlier, we demonstrated the efficacy of N-hydroxyindole-based LDH-A inhibitors in different cancer types. In this study we describe the efficacy of NHI-Glc-2, which is designed to dual target cancer cells, by exploiting a simultaneous enhanced glucose uptake by overexpressed glucose transporter 1 (GLUT1) and by inhibition of LDH-A. NHI-Glc-2 inhibits LDH-A enzyme activity, PANC-1 cell growth and disrupts spheroid integrity, with an overall effect that is more pronounced when combined with gemcitabine.