Metabolic Alterations in Cancer and Their Potential as Therapeutic Targets

RAD23B mediated proteasomal degradation occurs through p38 MAPK/ATF-2/RAD23B axis under nutrient-deprived conditions in breast cancer

Metabolic reprogramming in cancer occurs due to interaction of cells with the surrounding tumor microenvironment. In the microenvironment of solid tumors, nutrient deprivation is induced by high consumption of nutrients and insufficient vasculature. Tumor cells alter their metabolic strategies to adapt to the microenvironment. To understand the role of these metabolic changes, in the current study, we have mimicked nutrient deprivation condition in vitro to evaluate the associated signaling pathways in breast cancer cells. In our study, we have shown that nutritional deprivation activated p38 MAPK and activating transcription factor-2 (ATF-2) by increased phosphorylation of Thr180/Tyr182 and Thr71, respectively, in breast cancer cells. Pharmacological inhibition of p38 MAPK showed increased cell viability and reduced expression of ATF-2 and RAD23B under nutrient starvation conditions. Further, silencing of ATF-2 showed increased cell viability and decreased expression of RAD23B under nutrient starvation conditions. This suggests the involvement of p38 MAPK/ATF-2/RAD23B axis as a signaling pathway under nutrition starvation in breast cancer cells. The RAD23B mediated proteasome activity was shown to be much higher under stress conditions indicating a crucial role of RAD23B as a target for breast cancer.

A Robust Metabolic Enzyme-Based Prognostic Signature for Head and Neck Squamous Cell Carcinoma

Background

Head and neck squamous cell carcinoma (HNSCC) is still a menace to public wellbeing globally. However, the underlying molecular events influencing the carcinogenesis and prognosis of HNSCC are poorly known.

Methods

Gene expression profiles of The Cancer Genome Atlas (TCGA) HNSCC dataset and GSE37991 were downloaded from the TCGA database and gene expression omnibus, respectively. The common differentially expressed metabolic enzymes (DEMEs) between HNSCC tissues and normal controls were screened out. Then a DEME-based molecular signature and a clinically practical nomogram model were constructed and validated.

Results

A total of 23 commonly upregulated and 9 commonly downregulated DEMEs were identified in TCGA HNSCC and GSE37991. Gene ontology analyses of the common DEMEs revealed that alpha-amino acid metabolic process, glycosyl compound metabolic process, and cellular amino acid metabolic process were enriched. Based on the TCGA HNSCC cohort, we have built up a robust DEME-based prognostic signature including HPRT1, PLOD2, ASNS, TXNRD1, CYP27B1, and FUT6 for predicting the clinical outcome of HNSCC. Furthermore, this prognosis signature was successfully validated in another independent cohort GSE65858. Moreover, a potent prognostic signature-based nomogram model was constructed to provide personalized therapeutic guidance for treating HNSCC. In vitro experiment revealed that the knockdown of TXNRD1 suppressed malignant activities of HNSCC cells.

Conclusion

Our study has successfully developed a robust DEME-based signature for predicting the prognosis of HNSCC. Moreover, the nomogram model might provide useful guidance for the precision treatment of HNSCC.

Glutamine promotes escape from therapy-induced senescence in tumor cells

Therapy-induced senescence (TIS) is a major cellular response to anticancer therapies. While induction of a persistent growth arrest would be a desirable outcome in cancer therapy, it has been shown that, unlike normal cells, cancer cells are able to evade the senescence cell cycle arrest and to resume proliferation, likely contributing to tumor relapse. Notably, cells that escape from TIS acquire a plastic, stem cell-like phenotype. The metabolic dependencies of cells that evade senescence have not been thoroughly studied. In this study, we show that glutamine depletion inhibits escape from TIS in all cell lines studied, and reduces the stem cell subpopulation. In line with a metabolic reliance on glutamine, escaped clones overexpress the glutamine transporter SLC1A5. We also demonstrate a central role of glutamine synthetase that mediates resistance to glutamine deprivation, conferring independence from exogenous glutamine. Finally, rescue experiments demonstrate that glutamine provides nitrogen for nucleotides biosynthesis in cells that escape from TIS, but also suggest a critical involvement of glutamine in other metabolic and non-metabolic pathways. On the whole, these results reveal a metabolic vulnerability of cancer stem cells that recover proliferation after exposure to anticancer therapies, which could be exploited to prevent tumor recurrence.

Targeting Tumor Immunosuppressive Microenvironment for the Prevention of Hepatic Cancer: Applications of Traditional Chinese Medicines in Targeted Delivery

Traditional Chinese Medicine (TCM) is one of the ancient and most accepted alternative medicinal systems in the world for the treatment of health ailments. World Health Organization recognizes TCM as one of the primary healthcare practices followed across the globe. TCM utilizes a holistic approach for the diagnosis and treatment of cancers. The tumor microenvironment (TME) surrounds cancer cells and plays pivotal roles in tumor development, growth, progression, and therapy resistance. TME is a hypoxic and acidic environment that includes immune cells, pericytes, fibroblasts, endothelial cells, various cytokines, growth factors, and extracellular matrix components. Targeting TME using targeted drug delivery and nanoparticles is an attractive strategy for the treatment of solid tumors and recently has received significant research attention under precise medicine concept. TME plays a pivotal role in the overall survival and metastasis of a tumor by stimulating cell proliferation, preventing the tumor clearance by the immune cells, enhancing the oncogenic potential of the cancer cells, and promoting tumor invasion. Hepatocellular Carcinoma (HCC) is one of the major causes of cancer-associated deaths affecting millions of individuals worldwide each year. TCM herbs contain several bioactive phytoconstituents with a broad range of biological, physiological, and immunological effects on the system. Several TCM herbs and their monomers have shown inhibitory effects in HCC by controlling the TME. This study reviews the fundamentals and applications of targeting strategies for immunosuppressing TME to treat cancers. This study focuses on TME targeting strategies using TCM herbs and the molecular mechanisms of several TCM herbs and their monomers on controlling TME.

Xanthatin inhibits human colon cancer cells progression via mTOR signaling mediated energy metabolism alteration

Tumor cells exhibit higher glycolysis and rely on abnormal energy metabolism to produce ATP, which is essential for cell proliferation and migration. Abnormal energy metabolism inhibition is considered a promising tumor treatment strategy. Xanthatin is an active sesquiterpene lactone isolated from Xanthium strumarium L. This study evaluated the effect of xanthatin on the energy metabolism of human colon cancer cells. The results showed that xanthatin significantly inhibited the migration and invasion of human HT-29 and HCT-116 colon cancer cells. We found that xanthatin effectively reduced the production of ATP and promoted the accumulation of lactate. Xanthatin inhibited glycolysis which may be related to the reduction of glucose transporter 1 (Glut1) and monocarboxylate transporter 4 (MCT4) mRNA and protein levels. Concomitantly, xanthatin promoted complex II activity and oxidative phosphorylation (OXPHOS), resulting in mitochondrial damage and cell death in HT-29 cells. Furthermore, xanthatin inhibited the phosphorylation of mTOR, the phosphorylation of 4E-binding protein 1 (4E-BP1) and c-myc in HT-29 cells. Moreover, rapamycin, a mTOR inhibitor, could enhance the cytotoxicity effect in xanthatin treated HT-29 cells. Additionally, HT-29 cells transfected with si-mTOR aggravated xanthatin induced cell viability inhibition. Based on these results, we observed that the effect of xanthatin on energy metabolism may be related to its inhibition of the mTOR signaling pathway. Collectively, this study provides important insights into xanthatin's anticancer effect, which occurs by regulation of the energy metabolism of human colon cancer cells, and suggest that xanthatin has potential as a botanical drug against abnormal tumor energy metabolism.

Antiglycolytic Activities of Strobilanthes crispus Active Fraction and its Bioactive Components on Triple-Negative Breast Cancer Cells In Vitro

BACKGROUND

Survival and progression of cancer cells are highly dependent on aerobic glycolysis. Strobilanthes crispus has been shown to have promising anticancer effects on breast cancer cells. The involvement of the glycolysis pathway in producing these effects is unconfirmed, thus further investigation is required to elucidate this phenomenon.

OBJECTIVE

This study aims to determine the effect of S. crispus active fraction (F3) and its bioactive components on glycolysis in triple-negative breast cancer cells (MDA-MB-231).

METHODS

This study utilizes F3, lutein, β-sitosterol, and stigmasterol to be administered in MDA-MB-231 cells for measurement of antiglycolytic activities through cell poliferation, glucose uptake, and lactate concentration assays. Cell proliferation was assessed by MTT assay of MDA-MB-231 cells after treatment with F3 and its bioactive components lutein, β-sitosterol, and stigmasterol. The IC50 value in each compound was determined by MTT assay to be used in subsequent assays. The determination of glucose uptake activity and lactate concentration were quantified using fluorescence spectrophotometry.

RESULTS

Antiproliferative activities were observed for F3 and its bioactive components, with IC50 values of 100 µg/mL (F3), 20 µM (lutein), 25 µM (β-sitosterol), and 90 μM (stigmasterol) in MDA-MB-231 cells at 48 h. The percentage of glucose uptake and lactate concentration in MDA-MB-231 cells treated with F3, lutein, or β sitosterol were significantly lower than those observed in the untreated cells in a time-dependent manner. However, treatment with stigmasterol decreased the concentration of lactate without affecting the glucose uptake in MDA-MB-231 cells.

CONCLUSION

The antiglycolytic activities of F3 on MDA-MB-231 cells are attributed to its bioactive components.

Effects of the Novel PFKFB3 Inhibitor KAN0438757 on Colorectal Cancer Cells and Its Systemic Toxicity Evaluation In Vivo

BACKGROUND

Despite substantial progress made in the last decades in colorectal cancer (CRC) research, new treatment approaches are still needed to improve patients' long-term survival. To date, the promising strategy to target tumor angiogenesis metabolically together with a sensitization of CRC to chemo- and/or radiotherapy by PFKFB3 (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase-3) inhibition has never been tested. Therefore, initial evaluation and validation of newly developed compounds such as KAN0438757 and their effects on CRC cells are crucial steps preceding to in vivo preclinical studies, which in turn may consolidate new therapeutic targets.

MATERIALS AND METHODS

The efficiency of KAN0438757 to block PFKFB3 expression and translation in human CRC cells was evaluated by immunoblotting and real-time PCR. Functional in vitro assays assessed the effects of KAN0438757 on cell viability, proliferation, survival, adhesion, migration and invasion. Additionally, we evaluated the effects of KAN0438757 on matched patient-derived normal and tumor organoids and its systemic toxicity in vivo in C57BL6/N mice.

RESULTS

High PFKFB3 expression is correlated with a worse survival in CRC patients. KAN0438757 reduces PFKFB3 protein expression without affecting its transcriptional regulation. Additionally, a concentration-dependent anti-proliferative effect was observed. The migration and invasion capacity of cancer cells were significantly reduced, independent of the anti-proliferative effect. When treating colonic patient-derived organoids with KAN0438757 an impressive effect on tumor organoids growth was apparent, surprisingly sparing normal colonic organoids. No high-grade toxicity was observed in vivo.

CONCLUSION

The PFKFB3 inhibitor KAN0438757 significantly reduced CRC cell migration, invasion and survival. Moreover, on patient-derived cancer organoids KAN0438757 showed significant effects on growth, without being overly toxic in normal colon organoids and healthy mice. Our findings strongly encourage further translational studies to evaluate KAN0438757 in CRC therapy.

X-change symposium: status and future of modern radiation oncology-from technology to biology

Future radiation oncology encompasses a broad spectrum of topics ranging from modern clinical trial design to treatment and imaging technology and biology. In more detail, the application of hybrid MRI devices in modern image-guided radiotherapy; the emerging field of radiomics; the role of molecular imaging using positron emission tomography and its integration into clinical routine; radiation biology with its future perspectives, the role of molecular signatures in prognostic modelling; as well as special treatment modalities such as brachytherapy or proton beam therapy are areas of rapid development. More clinically, radiation oncology will certainly find an important role in the management of oligometastasis. The treatment spectrum will also be widened by the rational integration of modern systemic targeted or immune therapies into multimodal treatment strategies. All these developments will require a concise rethinking of clinical trial design. This article reviews the current status and the potential developments in the field of radiation oncology as discussed by a panel of European and international experts sharing their vision during the "X-Change" symposium, held in July 2019 in Munich (Germany).

A Metabolic Gene Signature to Predict Overall Survival in Head and Neck Squamous Cell Carcinoma

Background

Head and neck squamous cell carcinoma (HNSCC) is a common malignancy that emanates from the lips, mouth, paranasal sinuses, oropharynx, larynx, nasopharynx, and from other pharyngeal cancers. The availability of high-throughput expression data has made it possible to use global gene expression data to analyze the relationship between metabolic-related gene expression and clinical outcomes in HNSCC patients.

Method

In this study, we used RNA sequencing (RNA-seq) data from the cancer genome atlas (TCGA), with validation in the GEO dataset to profile the metabolic microenvironment and define potential biomarkers for metabolic therapy.

Results

We extracted data for 529 patients and 327 metabolic genes (198 upregulated and 129 downregulated genes) in the TCGA database. Carbonic anhydrase 9 (CA9) and CA6 had the largest logFCs in the upregulated and downregulated genes, respectively. Our Cox regression model data showed 51 prognostic-related genes with lysocardiolipin acyltransferase 1 (LCLAT1) and choline dehydrogenase (CHDH) being associated with the highest risk (HR = 1.144, 95% CI = 1.044 ~ 1.251) and the lowest risk (HR = 0.580, 95% CI = 0.400 ~ 0.839) in HNSCC, respectively. We next used the ROC curve to evaluate whether the differentially expressed metabolic-related genes could serve as early predictors of HNSCC. The findings showed an AUC of 0.745 and 0.618 in the TCGA and GEO analysis, respectively. Besides, the ability for the genes to predict clinicopathological HNSCC status was analyzed and the data showed that the AUC for age, gender, grade, stage, T, M, and N was 0.520, 0.495, 0.568, 0.606, 0.577, 0.476, and 0.673, respectively, in the TCGA dataset. On the other hand, the AUC for age, gender, stage, T, M, N, smoking, and HPV16-pos was 0.599, 0.531, 0.622, 0.606, 0.616, 0.550, 0.614, 0.519, and 0.397, respectively, in the GEO dataset.

Conclusion

Taken together, our study unearths a novel metabolic gene signature for the prediction of HNSCC prognosis based on the TCGA dataset. Our signature might point out the metabolic microenvironment disorders and provides potential treatment targets and prognostic biomarkers.

Microbes in Tumoral In Situ Tissues and in Tumorigenesis

Cancerous tumors are severe diseases affecting human health that have a complicated etiology and pathogenesis. Microbes have been considered to be related to the development and progression of numerous tumors through various pathogenic mechanisms in recent studies. Bacteria, which have so far remained the most studied microbes worldwide, have four major possible special pathogenic mechanisms (modulation of inflammation, immunity, DNA damage, and metabolism) that are related to carcinogenesis. This review aims to macroscopically summarize and verify the relationships between microbes and tumoral in situ tissues from cancers of four major different systems (urinary, respiratory, digestive, and reproductive); the abovementioned four microbial pathogenic mechanisms, as well as some synergistic pathogenic mechanisms, are also discussed. Once the etiologic role of microbes and their precise pathogenic mechanisms in carcinogenesis are known, the early prevention, diagnosis, and treatment of cancers would progress significantly.

miR-15a-5p inhibits metastasis and lipid metabolism by suppressing histone acetylation in lung cancer

Metabolic reprogramme was a key characteristic of malignant tumors. Increased evidences indicated that besides Warburg effect (abnormal glucose metabolism), abnormal lipid metabolism played more and more important in progression and metastasis of malignant tumors. MiR-15a-5p could inhibit development of lung cancer, while its regulating mechanism, especially the role in lipid metabolism still remained unclear. In this study, we confirmed that miR-15a-5p inhibited proliferation, migration and invasion of lung cancer cells. The online analysis of Mirpath v.3 predicted that miR-15a-5p was closely associated with fatty acid synthesis and lipid metabolism. In vitro cell experiments revealed that miR-15a-5p significantly suppressed fatty acid synthesis of lung cancer cells by inhibiting acetate uptake. Extensive analysis indicated that miR-15a-5p could suppress acetyl-CoA activity and decrease histone H4 acetylation by inhibiting ACSS2 expression. In addition, we also observed that ACSS2 located in nucleus under hypoxic conditions, while miR-15a-5p could be transported into nucleus to inhibit the function of ACSS2. Our study unveiled a novel mechanism of miR-15a-5p in inhibiting metastasis of lung cancer cells by suppressing lipid metabolism via suppression of ACSS2 mediated acetyl-CoA activity and histone acetylation.

Genomic and metabolomic analysis of step-wise malignant transformation in human skin fibroblasts

Metabolic changes accompanying a step-wise malignant transformation was investigated using a syngeneic lineage of human fibroblasts. Cell immortalization was associated with minor alterations in metabolism. Consecutive loss of cell cycle inhibition in immortalized cells resulted in increased levels of oxidative phosphorylation (OXPHOS). Overexpression of the H-Ras oncoprotein produced cells forming sarcomas in athymic mice. These transformed cells exhibited increased glucose consumption, glycolysis and a further increase in OXPHOS. Because of the markedly increased OXPHOS in transformed cells, the impact of a transaminase inhibitor, aminooxyacetic acid (AOA), which decreases glutamine influx to the tricarboxylic acid (TCA) cycle, was tested. Indeed, AOA significantly decreased proliferation of malignantly transformed fibroblasts and fibrosarcoma-derived cells in vitro and in vivo. AOA also decreased proliferation of cells susceptible to malignant transformation. Metabolomic studies in normal and transformed cells indicated that, in addition to the anticipated effect on the TCA cycle, AOA decreased production of nucleotides adenosine triphosphate (ATP) and uridine monophosphate. Exogenous nucleotides partially rescued decreased proliferation of the malignant cells treated with AOA. Our data indicate that AOA blocks several metabolic pathways essential for growth of malignant cells. Therefore, OXPHOS may provide important therapeutic targets for treatment of sarcoma.

High Expression of miR-206 Predicts Adverse Outcomes: A Potential Therapeutic Target for Esophageal Cancer

BACKGROUND

MicroRNA-206 (miR-206) inhibits cell proliferation, invasion and migration in a variety of tumors, but the prognostic value of its Esophageal Cancer (EC) remains unclear.

OBJECTIVE

To study the role of miR-206 in EC.

METHODS

The datasets of RNA-Seq, miRNA-Seq, methylation, copy number variation (CNV), and clinical follow-up information were download from The Cancer Genome Atlas (TCGA). After integration and standardization, the prognostic value and potential function of miR-206 were analyzed. The important roles of miR-206 expression in EC genetic and epigenetic mechanisms were analyzed by RNA-Seq, miRNA-Seq, and methylation data. The potential mechanism of CNV in different miR-206 expression groups was analyzed using GISTIC.

RESULTS

High expression of miR-206 was associated with poor outcome of EC (OS: p=0.005, AUC=0.69, N=178). Transforming growth factor β (TGF-β) signaling pathway, Wnt signaling pathway, mitogen-activated protein kinases (MAPK) signaling pathway, mammalian target of rapamycin (mTOR) signaling pathway were inhibited in high expression group. the aberrant methylation sites in the high and low expression groups were mainly distributed in the promoter region containing CpG islands, and there were different copy number patterns in the H and L samples, and the genes in the differential copy number were mainly enriched in cancer-related pathways, such as thyroid cancer, central carbon metabolism.

CONCLUSION

This study explored the unique genomic and epigenetic landscape associated with the expression of miR-206, provided evidence of mir-206 as a prognostic biomarker or a potential therapeutic target for EC patients.

Bioinformatics Analysis of Metabolomics Data Unveils Association of Metabolic Signatures with Methylation in Breast Cancer

Breast cancer (BC) contributes the highest global cancer mortality in women. BC tumors are highly heterogeneous, so subtyping by cell-surface markers is inadequate. Omics-driven tumor stratification is urgently needed to better understand BC and tailor therapies for personalized medicine. We used unsupervised k-means and partition around medoids (pam) to cluster metabolomics data from two data sets. The first comprised 271 BC tumors (data set 1) that were estrogen receptor (ER) positive (ER+, n = 204) or negative (ER-, n = 67) with 162 identified and validated metabolites. The second data set contained 67 BC samples (data set 2; ER+, n = 33; ER-, n = 34) and 352 known metabolites. Significance Analysis of Microarrays (SAM) was used to identify the most significant metabolites among these clusters, which were then reassigned into new clusters using prediction analysis of microarrays (PAM). Generally, metabolome-defined BC subtypes identified from either data set 1 or data set 2 were different from the well-known receptor- or transcriptome-defined subtypes. Metabolomics-directed clustering of data set 2 identified distinctive BC tumors characterized by metabolome profiles that associated with DNA methylation (p-value = 0.000 048, χ² test). Pathway analysis of cluster metabolites revealed that nitrogen metabolism and aminoacyl-tRNA biosynthesis were highly related to BC subtyping. The pipeline may be run from GitHub: https://github.com/FADHLyemen/Metabolomics_signature. Our proposed bioinformatics pipeline analyzed metabolomics data from BC tumors, revealing clusters characterized by unique metabolic signatures that may potentially stratify BC patients and tailor precision treatment.

Metabolic Reprogramming and Epithelial-Mesenchymal Plasticity: Opportunities and Challenges for Cancer Therapy

Metabolic reprogramming and epithelial-mesenchymal plasticity are both hallmarks of the adaptation of cancer cells for tumor growth and progression. For metabolic changes, cancer cells alter metabolism by utilizing glucose, lipids, and amino acids to meet the requirement of rapid proliferation and to endure stressful environments. Dynamic changes between the epithelial and mesenchymal phenotypes through epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) are critical steps for cancer invasion and metastatic colonization. Compared to the extensively studied metabolic reprogramming in tumorigenesis, the metabolic changes in metastasis are relatively unclear. Here, we review metabolic reprogramming, epithelial-mesenchymal plasticity, and their mutual influences on tumor cells. We also review the developing treatments for targeting cancer metabolism and the impact of metabolic targeting on EMT. In summary, understanding the metabolic adaption and phenotypic plasticity will be mandatory for developing new strategies to target metastatic and refractory cancers that are intractable to current treatments.

WNT5B exerts oncogenic effects and is negatively regulated by miR-5587-3p in lung adenocarcinoma progression

WNT5B glycoprotein belongs to the Wnt protein family. Limited investigations revealed a possible role of WNT5B in malignancies, such as triple-negative breast cancer and oral squamous cell carcinoma. However, whether WNT5B contributes to the progression of lung adenocarcinoma (LAD) remains unclear. Here, we initially determine that WNT5B is highly expressed in LAD and is positively correlated with lymph node metastasis and TNM stage. Consistently, clinical analysis reveals WNT5B as an independent prognostic biomarker in LAD. Silencing WNT5B suppresses the proliferation of LAD both in vitro and in vivo by interfering G1/S cell-cycle progression and modulating amino acid metabolism, revealing its remarkable oncogenic role in LAD. Of note, we also identified miR-5587-3p as a negative upstream regulator of WNT5B in LAD, which may help develop therapies targeting LAD patients with high WNT5B expression. Taken together, our results revealed an oncogenic role of WNT5B in LAD, which could be a prognostic biomarker and promising therapeutic target for LAD patients.