High expressions of LDHA and AMPK as prognostic biomarkers for breast cancer

Naphthoquinone-derived ZSW-4B induces apoptosis in triple-negative breast cancer via AMPK signalling activation

Triple-negative breast cancer (TNBC) is the most malignant molecular subtype of breast cancer and is characterized by aggressiveness, high mortality, significant heterogeneity, and poor prognosis. AMPK plays a critical role in maintaining the cellular energy balance, and its inactivation is associated with malignant breast cancer. Here, we identified the pharmacological mechanism of the 1,4-naphthoquinone derivative ZSW-4B. MTT, colony formation, and nude mouse xenograft tumour models demonstrated that ZSW-4B selectively inhibits the proliferation of TNBC cells both in vitro and in vivo. Flow cytometry and Western blot analysis revealed that ZSW-4B induces apoptosis in TNBC cells. Phosphoproteomic analysis revealed activation of the AMPK signalling pathway by ZSW-4B. Additionally, the application of the CRISPR-Cas9 system to genetically knockout AMPK in TNBC cell lines was demonstrated to reverse the antitumour effects elicited by ZSW-4B both in vitro and in vivo. In summary, ZSW-4B inhibits TNBC by inducing cellular apoptosis through the activation of AMPK.

Replenishment of TCA cycle intermediates and long-noncoding RNAs regulation in breast cancer

The tricarboxylic acid (TCA) cycle is an essential interface that coordinates cellular metabolism and is as a primary route determining the fate of a variety of fuel sources, including glucose, fatty acid and glutamate. The crosstalk of nutrients replenished TCA cycle regulates breast cancer (BC) progression by changing substrate levels-induced epigenetic alterations, especially the methylation, acetylation, succinylation and lactylation. Long non-coding RNAs (lncRNA) have dual roles in inhibiting or promoting energy reprogramming, and so altering the metabolic flux of fuel sources to the TCA cycle, which may regulate epigenetic modifications at the cellular level of BC. This narrative review discussed the central role of the TCA cycle in interconnecting numerous fuels and the induced epigenetic modifications, and the underlying regulatory mechanisms of lncRNAs in BC.

Next-generation biomarkers for prognostic and potential therapeutic enhancement in Triple negative breast cancer

Triple-negative breast carcinoma (TNBC) is one of the most challenging subtypes of breast carcinoma and it has very limited therapeutic options as it is highly aggressive. The prognostic biomarkers are crucial for early diagnosis of the tumor, it also helps in anticipating the trajectory of the illness and optimizing the therapy options. Several therapeutic biomarkers are being used. Among them, the next-generation biomarkers that include Circulating tumor (ct) DNA, glycogen, lipid, and exosome biomarkers provide intriguing opportunities for enhancing the prognosis of TNBC. Lipid and glycogen biomarkers serve as essential details on the development of the tumor along with the efficacy of the treatment, as it exhibits metabolic alteration linked to TNBC. Several types of biomarkers have predictive abilities in TNBC. Elevated levels are associated with worse outcomes. ctDNA being a noninvasive biomarker reveals the genetic composition of the tumor, as well as helps to monitor the progression of the disease. Traditional therapies are ineffective in TNBC due to a lack of receptors, targeted drug delivery provides a tailored approach to overcome drug resistance and site-specific action by minimizing the side effects in TNBC treatment. This enhances therapeutic outcomes against the aggressive nature of breast cancer. This paper includes all the recent biomarkers which has been researched so far in TNBC and the state of art for TNBC which is explored.

Exploring the impact of circRNAs on cancer glycolysis: Insights into tumor progression and therapeutic strategies

Cancer cells exhibit altered metabolic pathways, prominently featuring enhanced glycolytic activity to sustain their rapid growth and proliferation. Dysregulation of glycolysis is a well-established hallmark of cancer and contributes to tumor progression and resistance to therapy. Increased glycolysis supplies the energy necessary for increased proliferation and creates an acidic milieu, which in turn encourages tumor cells' infiltration, metastasis, and chemoresistance. Circular RNAs (circRNAs) have emerged as pivotal players in diverse biological processes, including cancer development and metabolic reprogramming. The interplay between circRNAs and glycolysis is explored, illuminating how circRNAs regulate key glycolysis-associated genes and enzymes, thereby influencing tumor metabolic profiles. In this overview, we highlight the mechanisms by which circRNAs regulate glycolytic enzymes and modulate glycolysis. In addition, we discuss the clinical implications of dysregulated circRNAs in cancer glycolysis, including their potential use as diagnostic and prognostic biomarkers. All in all, in this overview, we provide the most recent findings on how circRNAs operate at the molecular level to control glycolysis in various types of cancer, including hepatocellular carcinoma (HCC), prostate cancer (PCa), colorectal cancer (CRC), cervical cancer (CC), glioma, non-small cell lung cancer (NSCLC), breast cancer, and gastric cancer (GC). In conclusion, this review provides a comprehensive overview of the significance of circRNAs in cancer glycolysis, shedding light on their intricate roles in tumor development and presenting innovative therapeutic avenues.

Redox and metabolic reprogramming in breast cancer and cancer-associated adipose tissue

Redox and metabolic processes are tightly coupled in both physiological and pathological conditions. In cancer, their integration occurs at multiple levels and is characterized by synchronized reprogramming both in the tumor tissue and its specific but heterogeneous microenvironment. In breast cancer, the principal microenvironment is the cancer-associated adipose tissue (CAAT). Understanding how the redox-metabolic reprogramming becomes coordinated in human breast cancer is imperative both for cancer prevention and for the establishment of new therapeutic approaches. This review aims to provide an overview of the current knowledge of the redox profiles and regulation of intermediary metabolism in breast cancer while considering the tumor and CAAT of breast cancer as a unique Warburg's pseudo-organ. As cancer is now recognized as a systemic metabolic disease, we have paid particular attention to the cell-specific redox-metabolic reprogramming and the roles of estrogen receptors and circadian rhythms, as well as their crosstalk in the development, growth, progression, and prognosis of breast cancer.

The regulatory roles and clinical significance of glycolysis in tumor

Metabolic reprogramming has been demonstrated to have a significant impact on the biological behaviors of tumor cells, among which glycolysis is an important form. Recent research has revealed that the heightened glycolysis levels, the abnormal expression of glycolytic enzymes, and the accumulation of glycolytic products could regulate the growth, proliferation, invasion, and metastasis of tumor cells and provide a favorable microenvironment for tumor development and progression. Based on the distinctive glycolytic characteristics of tumor cells, novel imaging tests have been developed to evaluate tumor proliferation and metastasis. In addition, glycolytic enzymes have been found to serve as promising biomarkers in tumor, which could provide assistance in the early diagnosis and prognostic assessment of tumor patients. Numerous glycolytic enzymes have been identified as potential therapeutic targets for tumor treatment, and various small molecule inhibitors targeting glycolytic enzymes have been developed to inhibit tumor development and some of them are already applied in the clinic. In this review, we systematically summarized recent advances of the regulatory roles of glycolysis in tumor progression and highlighted the potential clinical significance of glycolytic enzymes and products as novel biomarkers and therapeutic targets in tumor treatment.

Proteo-transcriptomic profiles reveal key regulatory pathways and functions of LDHA in the ovulation of domestic chickens (Gallus gallus)

BACKGROUND

In poultry, the smooth transition of follicles from the preovulatory-to-postovulatory phase impacts egg production in hens and can benefit the poultry industry. However, the regulatory mechanism underlying follicular ovulation in avians is a complex biological process that remains unclear.

RESULTS

Critical biochemical events involved in ovulation in domestic chickens (Gallus gallus) were evaluated by transcriptomics, proteomics, and in vitro assays. Comparative transcriptome analyses of the largest preovulatory follicle (F1) and postovulatory follicle (POF1) in continuous laying (CL) and intermittent laying (IL) chickens indicated the greatest difference between CL_F1 and IL_F1, with 950 differentially expressed genes (DEGs), and the smallest difference between CL_POF1 and IL_POF1, with 14 DEGs. Additionally, data-independent acquisition proteomics revealed 252 differentially abundant proteins between CL_F1 and IL_F1. Perivitelline membrane synthesis, steroid biosynthesis, lysosomes, and oxidative phosphorylation were identified as pivotal pathways contributing to ovulation regulation. In particular, the regulation of zona pellucida sperm-binding protein 3, plasminogen activator, cathepsin A, and lactate dehydrogenase A (LDHA) was shown to be essential for ovulation. Furthermore, the inhibition of LDHA decreased cell viability and promoted apoptosis of ovarian follicles in vitro.

CONCLUSIONS

This study reveals several important biochemical events involved in the process of ovulation, as well as crucial role of LDHA. These findings improve our understanding of ovulation and its regulatory mechanisms in avian species.

Reprogramming of glucose metabolism: Metabolic alterations in the progression of osteosarcoma

Metabolic reprogramming is an adaptive response of tumour cells under hypoxia and low nutrition conditions. There is increasing evidence that glucose metabolism reprogramming can regulate the growth and metastasis of osteosarcoma (OS). Reprogramming in the progress of OS can bring opportunities for early diagnosis and treatment of OS. Previous research mainly focused on the glycolytic pathway of glucose metabolism, often neglecting the tricarboxylic acid cycle and pentose phosphate pathway. However, the tricarboxylic acid cycle and pentose phosphate pathway of glucose metabolism are also involved in the progression of OS and are closely related to this disease. The research on glucose metabolism in OS has not yet been summarized. In this review, we discuss the abnormal expression of key molecules related to glucose metabolism in OS and summarize the glucose metabolism related signaling pathways involved in the occurrence and development of OS. In addition, we discuss some of the targeted drugs that regulate glucose metabolism pathways, which can lead to effective strategies for targeted treatment of OS.

The potential protective effect of aqueous extract of Acanthophyllum glandulosum root on Streptozotocin-induced diabetes in mice

Purpose

Treatment of diabetes using traditional medicine has attracted attention in recent decades because of its unique benefits. Acanthophyllum glandulosum is known as an herb with therapeutic potential. This research explored the likely protective effects of Acanthophyllum Glandulosum Root (AGR) in mice with Streptozotocin-induced type 2 diabetes mellitus (T2DM) to provide complementary therapy.

Methods

Diabetes was induced by a single injection of Streptozotocin (STZ) in mice. STZ-diabetic mice were treated with oral dosages of AGR (25, 50, 100, and 200 mg/kg) on different experiment days. During the experiment, the effect of a topical extract of AGR on Glucose level, serum lipid profile, and liver and kidney biomarkers, with the histopathological assessment of heart, kidney, spleen, and liver, were investigated. The gene expression level of inflammation biomarkers (Tumour Necrosis Factor-alpha (TNF-α) and interleukin-1 (IL-1)), apoptosis factor (Caspase3), glucose regulatory genes (Glucose transporter (GLUT) 4 and 2), and lipid regulatory gene (Adenosine 50-monophosphate protein-kinase (AMPK)) were investigated.

Results

Administration of AGR to STZ-diabetic mice decreased blood glucose level (p < 0.01), normalized the lipid profile (p < 0.01), improved the serum level of kidney (p < 0.01) and liver biomarkers (p < 0.01), and normalized Kidney hypertrophy (p < 0.01), inflammation (p < 0.001), and apoptosis (p < 0.01). The AGR effect was better at 100 mg/kg than Metformin (100 mg/kg) on healing T2DM condition in mice.

Conclusion

AGR possesses anti-inflammatory, antioxidant, anti-hyperglycemic, anti-hyperlipidemic, and anti-glycation activity, thus exhibiting a protective function in STZ-induced diabetic mice. Further in vitro and in vivo works are necessary, especially to elucidate the mechanism of action of AGR at the cellular and molecular levels.

The Tumor Stemness Indice mRNAsi can Act as Molecular Typing Tool for Lung Adenocarcinoma

Due to the high heterogeneity, lung adenocarcinoma (LUAD) cannot be distinguished into precise molecular subtypes, thereby resulting in poor therapeutic effect and low 5-year survival rate clinically. Although the tumor stemness score (mRNAsi) has been shown to accurately characterize the similarity index of cancer stem cells (CSCs), whether mRNAsi can serve as an effective molecular typing tool for LUAD isn't reported to date. In this study, we first demonstrate that mRNAsi is significantly correlated with the prognosis and disease degree of LUAD patients, i.e., the higher the mRNAsi, the worse the prognosis and the higher the disease degree. Second, we identify 449 mRNAsi-related genes based on both weighted gene co-expression network analysis (WGCNA) and univariate regression analysis. Third, our results display that 449 mRNAsi-related genes can accurately distinguish the LUAD patients into two molecular subtypes: ms-H subtype (with high mRNAsi) and ms-L subtype (with low mRNAsi), particularly the ms-H subtype has a worse prognosis. Remarkably, significant differences in clinical characteristics, immune microenvironment, and somatic mutation exist between the two molecular subtypes, which might lead to the poorer prognosis of the ms-H subtype patients than that of the ms-L subtype ones. Finally, we establish a prognostic model containing 8 mRNAsi-related genes, which can effectively predict the survival rate of LUAD patients. Taken together, our work provides the first molecular subtype related to mRNAsi in LUAD, and reveals that these two molecular subtypes, the prognostic model and marker genes may have important clinical value for effectively monitoring and treating LUAD patients.

CENPE and LDHA were potential prognostic biomarkers of chromophobe renal cell carcinoma

BACKGROUND

Most sarcomatoid differentiated renal cell carcinoma was differentiated from Chromophobe renal cell carcinoma (KICH) and related to a bad prognosis. Thus, finding biomarkers is important for the therapy of KICH.

METHODS

The UCSC was used for determining the expression of mRNA and miRNA and clinical data in KICH and normal samples. KEGG and GO were used for predicting potential function of differently expressed genes (DEGs). Optimal prognostic markers were determined by Lasso regression. Kaplan-Meier survival, ROC, and cox regression were used for assessing prognosis value. GSEA was used for predicting potential function of markers. The relations between markers and immune cell infiltration were determined by Pearson method. The upstream miRNA of markers was predicted in TargetScan and DIANA.

RESULTS

The 6162 upregulated and 13,903 downregulated DEGs were identified in KICH. Further CENPE and LDHA were screened out as optimal prognostic risk signatures. CENPE was highly expressed while LDHA was lowly expressed in KICH samples, and the high expressions of 2 genes contributed to bad prognosis. The functions of CENPE and LDHA were mainly enriched in proliferation related pathways such as cell cycle and DNA replication. In addition, the correlation of 2 genes with immune infiltrates in KICH was also observed. Finally, we found that has-miR-577 was the common upstream of 2 genes and the binding sites can be predicted.

CONCLUSION

CENPE and LDHA were identified as the important prognostic biomarkers in KICH, and they might be involved in the proliferation of cancer cell.

The Impact of Tumor-Associated Macrophages Found at Mammary Carcinoma Sites is Dependent Upon the Tumor Type

BACKGROUND

Previously, we reported that tumor-associated macrophages (TAM) at early sites of mammary carcinoma showed a decrease in ATP production rate and a higher dependence on oxidative phosphorylation.

METHODS

Since these changes can result from activation of AMP-activated protein kinase (AMPK) and glucose transporter 1 (Glut1) during metabolic stress, we investigated whether the TAM showed increased expression of ampk and glut1, as well as another indicator of metabolic stress, pkm2. Indeed, the TAM exhibited significant expression of pkm2, glut1, and ampk.

RESULTS

Bone marrow-derived macrophages (BMDM) co-cultured with 4T1, EMT6, and 168 in vitro similarly showed increased expression of pkm2, glut1, and ampk. Moreover, lactate, which is expressed at significant levels by all three tumors, induced expression of these same genes in BMDM suggesting that lactate may induce a metabolic stress response in these TAM. Yet, the three different mammary carcinoma models benefited from different targeting strategies. Macrophage depletion studies revealed that the TAM contributed to growth of the EMT6 tumor and metastasis of the 4T1 tumor. Targeting the stress response with the Integrated Stress Response Inhibitor (ISRIB), which targets eIF2, impacted 168 tumor progression, and ISRIB as well as FX-11, which targets lactate dehydrogenase, impacted 4T1 tumor progression and metastasis.

CONCLUSIONS

Collectively, these data demonstrate that targeting TAM or metabolism at early tumor sites can impact tumor progression. However, variability in the responses underscore the fact that the impact of macrophages differs even within three different syngeneic mammary carcinoma models.

The impact of poor metabolic health on aggressive breast cancer: adipose tissue and tumor metabolism

Obesity and type 2 diabetes are chronic metabolic diseases that impact tens to hundreds of millions of adults, especially in developed countries. Each condition is associated with an elevated risk of breast cancer and with a poor prognosis after treatment. The mechanisms connecting poor metabolic health to breast cancer are numerous and include hyperinsulinemia, inflammation, excess nutrient availability, and adipose tissue dysfunction. Here, we focus on adipose tissue, highlighting important roles for both adipocytes and fibroblasts in breast cancer progression. One potentially important mediator of adipose tissue effects on breast cancer is the fibroblast growth factor receptor (FGFR) signaling network. Among the many roles of FGFR signaling, we postulate that key mechanisms driving aggressive breast cancer include epithelial-to-mesenchymal transition and cellular metabolic reprogramming. We also pose existing questions that may help better understand breast cancer biology in people with obesity, type 2 diabetes, and poor metabolic health.

Long non-coding RNA CCHE1 modulates LDHA-mediated glycolysis and confers chemoresistance to melanoma cells

Melanoma is considered as the most common metastatic skin cancer with increasing incidence and high mortality globally. The vital roles of long non-coding RNAs (lncRNAs) in the tumorigenesis of melanoma are elucidated by emerging evidence. The lncRNA cervical carcinoma high-expressed 1 (CCHE1) was overexpressed and acted as an oncogene in a variety of cancers, while the function of CCHE1 in melanoma remains unclear. Here, we found that CCHE1 was highly expressed in melanoma and correlated with the poorer survival of melanoma patients. Depletion of CCHE1 inhibited the proliferation, induced cell apoptosis and suppressed in vivo tumor growth. To further understand the functional mechanism of CCHE1, the interacting partners of CCHE1 were identified via RNA pull-down assay followed by mass spectrometry. CCHE1 was found to bind lactate dehydrogenase A (LDHA) and acted as a scaffold to enhance the interaction of LDHA with the fibroblast growth factor receptor type 1 (FGFR1), which consequently enhanced LDHA phosphorylation and activity of LDHA. Inhibiting CCHE1 strikingly suppressed the glycolytic flux of melanoma cells and lactate generation in vivo. Further study demonstrated that CCHE1 desensitized melanoma cells to dacarbazine and inhibition of glycolysis reversed CCHE1-induced chemoresistance. These results uncovered the novel function of CCHE1 in melanoma by reprogramming the glucose metabolism via orchestrating the activity of LDHA.

Targeting the p53 signaling pathway in cancers: Molecular mechanisms and clinical studies

Tumor suppressor p53 can transcriptionally activate downstream genes in response to stress, and then regulate the cell cycle, DNA repair, metabolism, angiogenesis, apoptosis, and other biological responses. p53 has seven functional domains and 12 splice isoforms, and different domains and subtypes play different roles. The activation and inactivation of p53 are finely regulated and are associated with phosphorylation/acetylation modification and ubiquitination modification, respectively. Abnormal activation of p53 is closely related to the occurrence and development of cancer. While targeted therapy of the p53 signaling pathway is still in its early stages and only a few drugs or treatments have entered clinical trials, the development of new drugs and ongoing clinical trials are expected to lead to the widespread use of p53 signaling-targeted therapy in cancer treatment in the future. TRIAP1 is a novel p53 downstream inhibitor of apoptosis. TRIAP1 is the homolog of yeast mitochondrial intermembrane protein MDM35, which can play a tumor-promoting role by blocking the mitochondria-dependent apoptosis pathway. This work provides a systematic overview of recent basic research and clinical progress in the p53 signaling pathway and proposes that TRIAP1 is an important therapeutic target downstream of p53 signaling.

Regulation of Autophagy via Carbohydrate and Lipid Metabolism in Cancer

Metabolic changes are an important component of tumor cell progression. Tumor cells adapt to environmental stresses via changes to carbohydrate and lipid metabolism. Autophagy, a physiological process in mammalian cells that digests damaged organelles and misfolded proteins via lysosomal degradation, is closely associated with metabolism in mammalian cells, acting as a meter of cellular ATP levels. In this review, we discuss the changes in glycolytic and lipid biosynthetic pathways in mammalian cells and their impact on carcinogenesis via the autophagy pathway. In addition, we discuss the impact of these metabolic pathways on autophagy in lung cancer.

Glycolysis-related lncRNA TMEM105 upregulates LDHA to facilitate breast cancer liver metastasis via sponging miR-1208

Increased glycolysis is one of the key metabolic hallmarks of cancer cells. However, the roles of lncRNAs in energy metabolism and cancer metastasis remain unclear. Here, the expression of TMEM105 associated with glycolysis was dramatically elevated from normal to breast cancer to breast cancer liver metastasis tissues, and the survival analysis revealed that high TMEM105 expression was related to poor survival, especially in patients with liver metastasis. Moreover, TMEM105 facilitated the glycolysis of breast cancer cells and induced cell invasion and breast cancer liver metastasis (BCLM). Mechanistically, TMEM105 regulated LDHA expression by sponging miR-1208, which further promoted cell glycolysis and BCLM. Importantly, glycolytic production of lactate enhanced TMEM105 expression in breast cancer cells by activating the SHH-MAZ signaling pathway. These findings suggested that the lactate-responsive TMEM105 acted as a miRNA sponge, inducing BCLM via a glycolysis-mediated positive feedback loop, which might be a rational target for the treatment of BCLM patients.

Novel Anti-Cancer Products Targeting AMPK: Natural Herbal Medicine against Breast Cancer

Breast cancer is a common cancer in women worldwide. The existing clinical treatment strategies have been able to limit the progression of breast cancer and cancer metastasis, but abnormal metabolism, immunosuppression, and multidrug resistance involving multiple regulators remain the major challenges for the treatment of breast cancer. Adenosine 5'-monophosphate (AMP)-Activated Protein Kinase (AMPK) can regulate metabolic reprogramming and reverse the "Warburg effect" via multiple metabolic signaling pathways in breast cancer. Previous studies suggest that the activation of AMPK suppresses the growth and metastasis of breast cancer cells, as well as stimulating the responses of immune cells. However, some other reports claim that the development and poor prognosis of breast cancer are related to the overexpression and aberrant activation of AMPK. Thus, the role of AMPK in the progression of breast cancer is still controversial. In this review, we summarize the current understanding of AMPK, particularly the comprehensive bidirectional functions of AMPK in cancer progression; discuss the pharmacological activators of AMPK and some specific molecules, including the natural products (including berberine, curcumin, (-)-epigallocatechin-3-gallate, ginsenosides, and paclitaxel) that influence the efficacy of these activators in cancer therapy; and elaborate the role of AMPK as a potential therapeutic target for the treatment of breast cancer.

Lactate in the tumor microenvironment: A rising star for targeted tumor therapy

Metabolic reprogramming is one of fourteen hallmarks of tumor cells, among which aerobic glycolysis, often known as the "Warburg effect," is essential to the fast proliferation and aggressive metastasis of tumor cells. Lactate, on the other hand, as a ubiquitous molecule in the tumor microenvironment (TME), is generated primarily by tumor cells undergoing glycolysis. To prevent intracellular acidification, malignant cells often remove lactate along with H⁺, yet the acidification of TME is inevitable. Not only does the highly concentrated lactate within the TME serve as a substrate to supply energy to the malignant cells, but it also works as a signal to activate multiple pathways that enhance tumor metastasis and invasion, intratumoral angiogenesis, as well as immune escape. In this review, we aim to discuss the latest findings on lactate metabolism in tumor cells, particularly the capacity of extracellular lactate to influence cells in the tumor microenvironment. In addition, we examine current treatment techniques employing existing medications that target and interfere with lactate generation and transport in cancer therapy. New research shows that targeting lactate metabolism, lactate-regulated cells, and lactate action pathways are viable cancer therapy strategies.

CA 15-3, CRP, and LDH correlates with prognostic parameters in canine mammary neoplasms

The identification of putative prognostic factors in canine mammary neoplasms (CMNs) has been focused on tissue-specific biomarkers, but the serum biomarkers, including cancer antigen 15-3 (CA 15-3), c-reactive protein (CRP), and lactate dehydrogenase (LDH) have been demonstrated to display clinical application in cases of CMNs. The aim of the study was to evaluate the levels of these serum biomarkers and their association with well-established prognostic factors in CMNs. Samples from 15 female canines with CMNs and 15 clinically healthy ones were collected. The results were evaluated using the Tukey's, Pearson, or Spearman tests. The cut-off point, sensitivity, specificity, and area under curve (AUC) were evaluated using the receiver operating characteristic (ROC) curve analysis in a logistic regression model (P<0.05). The levels of CA 15-3, CRP and LDH were significantly higher in the serum of female dogs with CMNs compared to the healthy ones. Moreover, these factors were positively correlated with ulceration, tumor size, histopathological grade, metastatic lymph node, and clinical staging. Female dogs with CMNs were found to exhibit highest serum levels of CA 15-3, CRP, and LDH. Therefore, they can be applied to improve the efficacy of the diagnosis and prognostic evaluation in casas of CMNs.

Breast cancer combined prognostic model based on lactate metabolism genes

To investigate the impact of lactate metabolism genes, lactate metabolism-related genes (LMRG), and immune infiltrating cells on the prognosis of breast cancer. LMRG was identified via single-cell sequencing. Immune cell infiltration was obtained by the CIBERSORT method. The prognostic genes were chosen by cox regression and the least absolute selection operator approach. lactate metabolism-associated immune-infiltrating cells was determined by difference analysis. The GSE20685 dataset was used as an external validation cohort. The model's prognostic usefulness was evaluated utilizing survival, immunological microenvironment, and drug sensitivity assessments. NDUFAF6 was most associated with breast cancer prognosis. We obtained a total of 450 LMRG. SUSD3, IL18, MAL2, and CDKN1C comprised the Model2. NK cell activation was most relevant to lactate metabolism. The combined prognostic model outperformed the individual model, with the area under the curve ranging from 0.7 to 0.8 in all three cohorts. The lactate metabolism-related combination model assisted in evaluating breast cancer prognosis, providing new insights for treatment, particularly immunotherapy.

Metabolic enzyme LDHA activates Rac1 GTPase as a noncanonical mechanism to promote cancer

The glycolytic enzyme lactate dehydrogenase A (LDHA) is frequently overexpressed in cancer, which promotes glycolysis and cancer. The oncogenic effect of LDHA has been attributed to its glycolytic enzyme activity. Here we report an unexpected noncanonical oncogenic mechanism of LDHA; LDHA activates small GTPase Rac1 to promote cancer independently of its glycolytic enzyme activity. Mechanistically, LDHA interacts with the active form of Rac1, Rac1-GTP, to inhibit Rac1-GTP interaction with its negative regulator, GTPase-activating proteins, leading to Rac1 activation in cancer cells and mouse tissues. In clinical breast cancer specimens, LDHA overexpression is associated with higher Rac1 activity. Rac1 inhibition suppresses the oncogenic effect of LDHA. Combination inhibition of LDHA enzyme activity and Rac1 activity by small-molecule inhibitors displays a synergistic inhibitory effect on breast cancers with LDHA overexpression. These results reveal a critical oncogenic mechanism of LDHA and suggest a promising therapeutic strategy for breast cancers with LDHA overexpression.

Energy metabolism pathways in breast cancer progression: The reprogramming, crosstalk, and potential therapeutic targets

Breast cancer (BC) is a malignant tumor that seriously endangers health in women. BC, like other cancers, is accompanied by metabolic reprogramming. Among energy metabolism-related pathways, BC exhibits enhanced glycolysis, tricarboxylic acid (TCA) cycle, pentose phosphate pathway (PPP), glutamate metabolism, and fatty acid metabolism activities. These pathways facilitate the proliferation, growth and migration of BC cells. The progression of BC is closely related to the alterations in the activity or expression level of several metabolic enzymes, which are regulated by the intrinsic factors such as the key signaling and transcription factors. The metabolic reprogramming in the progression of BC is attributed to the aberrant expression of the signaling and transcription factors associated with the energy metabolism pathways. Understanding the metabolic mechanisms underlying the development of BC will provide a druggable potential for BC treatment and drug discovery.

Peptide-based LDH5 inhibitors enter cancer cells and impair proliferation

Lactate dehydrogenase 5 (LDH5) is overexpressed in many cancers and is a potential target for anticancer therapy due to its role in aerobic glycolysis. Small-molecule drugs have been developed as competitive inhibitors to bind substrate/cofactor sites of LDH5, but none reached the clinic to date. Recently, we designed the first LDH5 non-competitive inhibitor, cGmC9, a peptide that inhibits protein-protein interactions required for LDH5 enzymatic activity. Peptides are gaining a large interest as anticancer agents to modulate intracellular protein-protein interactions not targetable by small molecules; however, delivery of these peptides to the cytosol, where LDH5 and other anticancer targets are located, remains a challenge for this class of therapeutics. In this study, we focused on the cellular internalisation of cGmC9 to achieve LDH5 inhibition in the cytosol. We designed cGmC9 analogues and compared them for LDH5 inhibition, cellular uptake, toxicity, and antiproliferation against a panel of cancer cell lines. The lead analogue, [R/r]cGmC9, specifically impairs proliferation of cancer cell lines with high glycolytic profiles. Proteomics analysis showed expected metabolic changes in response to decreased glycolysis. This is the first report of a peptide-based LDH5 inhibitor able to modulate cancer metabolism and kill cancer cells that are glycolytic. The current study demonstrates the potential of using peptides as inhibitors of intracellular protein-protein interactions relevant for cancer pathways and shows that active peptides can be rationally designed to improve their cell permeation.

A combination of novel NSC small molecule inhibitor along with doxorubicin inhibits proliferation of triple-negative breast cancer through metabolic reprogramming

Treatment of patients with triple-negative breast cancer (TNBC) has been challenging due to the absence of well-defined molecular targets and the highly invasive and proliferative nature of TNBC cells. Current treatments against TNBC have shown little promise due to high recurrence rate in patients. Consequently, there is a pressing need for novel and efficacious therapies against TNBC. Here, we report the discovery of a novel small molecule inhibitor (NSC33353) with potent anti-tumor activity against TNBC cells. The anti-proliferative effects of this small molecule inhibitor were determined using 2D and 3D cell proliferation assays. We found that NSC33353 significantly reduces the proliferation of TNBC cells in these assays. Using proteomics, next generation sequencing (NGS), and gene enrichment analysis, we investigated global regulatory pathways affected by this compound in TNBC cells. Proteomics data indicate a significant metabolic reprograming affecting both glycolytic enzymes and energy generation through oxidative phosphorylation. Subsequently, using metabolic (Seahorse) and enzymatic assays, we validated our proteomics and NGS analysis findings. Finally, we showed the inhibitory and anti-tumor effects of this small molecule in vitro and confirmed its inhibitory activity in vivo. Doxorubicin is one of the most effective agents in the treatment of TNBC and resistance to this drug has been a major problem. We show that the combination of NSC33353 and doxorubicin suppresses the growth of TNBC cells synergistically, suggesting that NSC33353 enhances TNBC sensitivity to doxorubicin. In summary, our data indicate that the small molecule inhibitor, NSC33353, exhibits anti-tumor activity in TNBC cells, and works in a synergistic fashion with a well-known chemotherapeutic agent.

Crosstalk between Immune Checkpoint Modulators, Metabolic Reprogramming and Cellular Plasticity in Triple-Negative Breast Cancer

Breast cancer is one of the major causes of mortality in women worldwide. Accounting for 15-20% of all breast cancer diagnoses, the triple-negative breast cancer (TNBC) subtype presents with an aggressive clinical course, heightened metastatic potential and the poorest short-term prognosis. TNBC does not respond to hormonal therapy, only partially responds to radio- and chemotherapy, and has limited targeted therapy options, thus underlining the critical need for better therapeutic treatments. Although immunotherapy based on immune checkpoint inhibition is emerging as a promising treatment option for TNBC patients, activation of cellular plasticity programs such as metabolic reprogramming (MR) and epithelial-to-mesenchymal transition (EMT) causes immunotherapy to fail. In this report, we review the role of MR and EMT in immune checkpoint dysregulation in TNBCs and specifically shed light on development of novel combination treatment modalities for this challenging disease. We highlight the clinical relevance of crosstalk between MR, EMT, and immune checkpoints in TNBCs.

Circ-CSNK1G1 promotes cell proliferation, migration, invasion and glycolysis metabolism during triple-negative breast cancer progression by modulating the miR-28-5p/LDHA pathway

BACKGROUND

Circular RNAs (circRNAs) play a vital role in cancer progression. However, there are still numerous circRNAs that have not been functionally explored. Our study aimed to disclose the role of circ-CSNK1G1 in triple-negative breast cancer (TNBC).

METHODS

The expression of circ-CSNK1G1, miR-28-5p and lactate dehydrogenase A (LDHA) mRNA was measured by quantitative real-time polymerase chain reaction (qPCR), and the expression of LDHA protein was measured by western blot. Cell proliferation was assessed using MTT assay and colony formation assay. Cell apoptosis was monitored using flow cytometry assay. Cell migration and cell invasion were investigated using transwell assay. Glycolysis progression was assessed according to glucose consumption, lactate production and ATP/ADP ratio. Tumor formation assay in nude mice was conducted to verify the role of circ-CSNK1G1 in vivo. The interplays between miR-28-5p and circ-CSNK1G1 or LDHA were confirmed by dual-luciferase reporter assay.

RESULTS

Circ-CSNK1G1 was upregulated in TNBC tissues and cells. Circ-CSNK1G1 knockdown suppressed cancer cell proliferation, migration, invasion and glycolysis energy metabolism, promoted cell apoptosis in vitro, and blocked tumor growth in vivo. Mechanism analysis showed that circ-CSNK1G1 positively regulated LDHA expression by suppressing miR-28-5p. Rescue experiments presented that circ-CSNK1G1 played functions by targeting miR-28-5p, and miR-28-5p participated in TNBC progression by degrading LDHA.

CONCLUSION

Circ-CSNK1G1 promotes cell proliferation, migration, invasion and glycolysis metabolism during TNBC development by regulating the miR-28-5p/LDHA pathway.

Oligo-Fucoidan supplementation enhances the effect of Olaparib on preventing metastasis and recurrence of triple-negative breast cancer in mice

BACKGROUND

Seaweed polysaccharides have been recommended as anticancer supplements and for boosting human health; however, their benefits in the treatment of triple-negative breast cancers (TNBCs) and improving immune surveillance remain unclear. Olaparib is a first-in-class poly (ADP-ribose) polymerase inhibitor. Oligo-Fucoidan, a low-molecular-weight sulfated polysaccharide purified from brown seaweed (Laminaria japonica), exhibits significant bioactivities that may aid in disease management.

METHODS

Macrophage polarity, clonogenic assays, cancer stemness properties, cancer cell trajectory, glucose metabolism, the TNBC 4T1 cells and a 4T1 syngeneic mouse model were used to inspect the therapeutic effects of olaparib and Oligo-Fucoidan supplementation on TNBC aggressiveness and microenvironment.

RESULTS

Olaparib treatment increased sub-G1 cell death and G2/M arrest in TNBC cells, and these effects were enhanced when Oligo-Fucoidan was added to treat the TNBC cells. The levels of Rad51 and programmed death-ligand 1 (PD-L1) and the activation of epidermal growth factor receptor (EGFR) and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) facilitate drug resistance and TNBC metastasis. However, the combination of olaparib and Oligo-Fucoidan synergistically reduced Rad51 and PD-L1 levels, as well as the activity of EGFR and AMPK; consistently, TNBC cytotoxicity and stemness were inhibited. Oligo-Fucoidan plus olaparib better inhibited the formation of TNBC stem cell mammospheroids with decreased subpopulations of CD44^high/CD24^low and EpCAM^high cells than monotherapy. Importantly, Oligo-Fucoidan plus olaparib repressed the oncogenic interleukin-6 (IL-6)/p-EGFR/PD-L1 pathway, glucose uptake and lactate production. Oligo-Fucoidan induced immunoactive and antitumoral M1 macrophages and attenuated the side effects of olaparib, such as the promotion on immunosuppressive and protumoral M2 macrophages. Furthermore, olaparib plus Oligo-Fucoidan dramatically suppressed M2 macrophage invasiveness and repolarized M2 to the M0-like (F4/80^high) and M1-like (CD80^high and CD86^high) phenotypes. In addition, olaparib- and Oligo-Fucoidan-pretreated TNBC cells resulted in the polarization of M0 macrophages into CD80(+) M1 but not CD163(+) M2 macrophages. Importantly, olaparib supplemented with oral administration of Oligo-Fucoidan in mice inhibited postsurgical TNBC recurrence and metastasis with increased cytotoxic T cells in the lymphatic system and decreased regulatory T cells and M2 macrophages in tumors.

CONCLUSION

Olaparib supplemented with natural compound Oligo-Fucoidan is a novel therapeutic strategy for reprogramming cancer stemness, metabolism and the microenvironment to prevent local postsurgical recurrence and distant metastasis. The combination therapy may advance therapeutic efficacy that prevent metastasis, chemoresistance and mortality in TNBC patients.

Type-2 diabetes mellitus-associated cancer risk: In pursuit of understanding the possible link

BACKGROUND AND AIM

The insulin resistance-mediated abnormal gluconeogenesis when exceeds a given threshold culminates in type 2 diabetes mellitus (T2DM). This induces severe cellular oxidative stress that may eventually facilitate typical neoplastic transformations. This narrative review aims to portray some of the plausible key mechanistic links bridging T2DM and specific cancers.

METHODS

A thorough literature search was conducted in the PubMedCentral database to retrieve information from various reputed biomedical reports/articles published from the year 2000. The information regarding the key biochemical signaling pathways mediating the carcinogenic transformation, especially in T2DM patients, was extensively excavated to systematically compile and present a narrative review.

RESULTS

T2DM-associated insulin resistance is known to negatively influence certain crucial genetic and metabolic components (such as insulin/IGFs, PI-3K/Akt, AMPK, and AGEs/RAGE) that may eventually lead to neoplastic transformation. In particular, the risk of developing cancers like pancreatic, colorectal, breast, liver, endometrial, and bladder seems to be more significant in T2DM patients.

CONCLUSION

Despite the fact that several studies have suggested a possible correlation between T2DM and cancer mortality, a more detailed research at both pre-clinical and clinical levels is still required so as to fully understand the intricate relationship and make a precise conclusion.

Metabolic targeting of malignant tumors: a need for systemic approach

PURPOSE

Dysregulated metabolism is now recognized as a fundamental hallmark of carcinogenesis inducing aggressive features and additional hallmarks. In this review, well-established metabolic changes displayed by tumors are highlighted in a comprehensive manner and corresponding therapeutical targets are discussed to set up a framework for integrating basic research findings with clinical translation in oncology setting.

METHODS

Recent manuscripts of high research impact and relevant to the field from PubMed (2000-2021) have been reviewed for this article.

RESULTS

Metabolic pathway disruption during tumor evolution is a dynamic process potentiating cell survival, dormancy, proliferation and invasion even under dismal conditions. Apart from cancer cells, though, tumor microenvironment has an acting role as extracellular metabolites, pH alterations and stromal cells reciprocally interact with malignant cells, ultimately dictating tumor-promoting responses, disabling anti-tumor immunity and promoting resistance to treatments.

CONCLUSION

In the field of cancer metabolism, there are several emerging prognostic and therapeutic targets either in the form of gene expression, enzyme activity or metabolites which could be exploited for clinical purposes; both standard-of-care and novel treatments may be evaluated in the context of metabolism rewiring and indeed, synergistic effects between metabolism-targeting and other therapies would be an attractive perspective for further research.

Triple-negative breast cancer drug resistance, durable efficacy, and cure: How advanced biological insights and emerging drug modalities could transform progress

INTRODUCTION

Triple-negative breast cancer (TNBC) is a heterogeneous disease characterized by the lack of estrogen receptor (ER), progesterone receptor (PR) and epidermal growth factor receptor 2 (HER2) and often associated with poor survival outcomes. The backbone of current treatments for TNBC relies on chemotherapy; however, resistance to cytotoxic agents is a commonly encountered hurdle to overcome.

AREAS COVERED

: Current understanding on the mechanisms involved in TNBC chemoresistance is evaluated and novel potential actionable targets and recently explored modalities for carrying and delivering chemotherapeutics are highlighted.

EXPERT OPINION

: A comprehensive identification of both genomic and functional TNBC signatures is required for a more definite categorization of the patients in order to prevent insensitivity to chemotherapy and therefore realize the full potential of precision-medicine approaches. In this scenario, cell-line-derived xenografts (CDX), patient-derived xenografts (PDX), patient-derived orthotopic xenografts (PDOX) and patient-derived organoids (PDO) are indispensable experimental models for evaluating the efficacy of drug candidates and predicting the therapeutic response. The combination of increasingly sensitive "omics" technologies, computational algorithms and innovative drug modalities may accelerate the successful translation of novel candidate TNBC targets from basic research to clinical settings, thus contributing to reach optimal clinical output, with lower side effects and reduced resistance.

Comparative characterization of 3D chromatin organization in triple-negative breast cancers

Triple-negative breast cancer (TNBC) is a malignant cancer subtype with a high risk of recurrence and an aggressive phenotype compared to other breast cancer subtypes. Although many breast cancer studies conducted to date have investigated genetic variations and differential target gene expression, how 3D chromatin architectures are reorganized in TNBC has been poorly elucidated. Here, using in situ Hi-C technology, we characterized the 3D chromatin organization in cells representing five distinct subtypes of breast cancer (including TNBC) compared to that in normal cells. We found that the global and local 3D architectures were severely disrupted in breast cancer. TNBC cell lines (especially BT549 cells) showed the most dramatic changes relative to normal cells. Importantly, we detected CTCF-dependent TNBC-susceptible losses/gains of 3D chromatin organization and found that these changes were strongly associated with perturbed chromatin accessibility and transcriptional dysregulation. In TNBC tissue, 3D chromatin disorganization was also observed relative to the 3D chromatin organization in normal tissues. We observed that the perturbed local 3D architectures found in TNBC cells were partially conserved in TNBC tissues. Finally, we discovered distinct tissue-specific chromatin loops by comparing normal and TNBC tissues. In this study, we elucidated the characteristics of the 3D chromatin organization in breast cancer relative to normal cells/tissues at multiple scales and identified associations between disrupted structures and various epigenetic features and transcriptomes. Collectively, our findings reveal important 3D chromatin structural features for future diagnostic and therapeutic studies of TNBC.

The 3D architecture of the genome is dramatically altered in an aggressive form of breast cancer, leading to changes in the regulation of gene expression that can fuel tumor growth. A team from South Korea, led by Hyeong-Gon Moon of Seoul National University College of Medicine and Daeyoup Lee of the Korea Advanced Institute of Science and Technology, Daejeon, detailed how chromosomes are positioned and folded within the nucleus of cell liness from five different subtypes of breast cancer. They found that triple-negative breast cancers displayed the most extreme reorganization of their genomes, a pattern also observed in biopsy tissues taken from patients with this subtype of cancer. Knowledge of these conformational changes could inform future efforts to develop therapies and diagnostics for patients with triple-negative breast tumors.

CmP Signaling Network Leads to Identification of Prognostic Biomarkers for Triple-Negative Breast Cancer in Caucasian Women

Objective: Triple-negative breast cancer (TNBC) constitutes ∼15% of all diagnosed invasive breast cancer cases with limited options for treatment since immunotherapies that target ER, PR, and HER2 receptors are ineffective. Progesterone (PRG) can induce its effects through either classic, nonclassic, or combined responses by binding to classic nuclear PRG receptors (nPRs) or nonclassic membrane PRG receptors (mPRs). Under PRG-induced actions, we previously demonstrated that the CCM signaling complex (CSC) can couple both nPRs and mPRs into a CmPn signaling network, which plays an important role during nPR(+) breast cancer tumorigenesis. We recently defined the novel CmP signaling network in African American women (AAW)-derived TNBC cells, which overlapped with our previously defined CmPn network in nPR(+) breast cancer cells. Methods: Under mPR-specific steroid actions, we measured alterations to key tumorigenic pathways in Caucasian American women (CAW)- derived TNBC cells, with RNAseq/proteomic and systems biology approaches. Exemption from ethics approval from IRB: This study only utilized cultured NBC cell lines with publicly available TNBC clinical data sets. Results: Our results demonstrated that TNBCs in CAW share similar altered signaling pathways, as TNBCs in AAW, under mPR-specific steroid actions, demonstrating the overall aggressive nature of TNBCs, regardless of racial differences. Furthermore, in this report, we have deconvoluted the CmP signalosome, using systems biology approaches and CAW-TNBC clinical data, to identify 21 new CAW-TNBC-specific prognostic biomarkers that reinforce the definitive role of CSC and mPR signaling during CAW-TNBC tumorigenesis. Conclusion: This new set of potential prognostic biomarkers may revolutionize molecular mechanisms and currently known concepts of tumorigenesis in CAW-TNBCs, leading to hopeful new therapeutic strategies.

SIRT5 Is the desuccinylase of LDHA as novel cancer metastatic stimulator in aggressive prostate cancer

Prostate cancer (PCa) is the most commonly diagnosed genital cancer in men worldwide. Among patients who developed advanced PCa, 80% suffered from bone metastasis, with a sharp drop in the survival rate. Despite great efforts, the detail of the mechanisms underlying castration-resistant PCa (CRPC) remain unclear. Sirtuin 5 (SIRT5), an NAD⁺-dependent desuccinylase, is hypothesized to be a key regulator of various cancers. However, compared to other SIRTs, the role of SIRT5 in cancer has not been extensively studied. Here, we showed significantly decreased SIRT5 levels in aggressive PCa cells relative to the PCa stages. The correlation between the decrease in the SIRT5 level and the patient's survival rate was also confirmed. Using quantitative global succinylome analysis, we characterized a significant increase of lysine 118 succinylation (K118su) of lactate dehydrogenase A (LDHA), which plays a role in increasing LDH activity. As a substrate of SIRT5, LDHA-K118su significantly increased the migration and invasion of PCa cells and LDH activity in PCa patients. This study investigated the reduction of SIRT5 and LDHA-K118su as a novel mechanism involved in PCa progression, which can also be proposed as a new target that can prevent CPRC progression, which is key to PCa treatment.

The critical function of metabolic reprogramming in cancer metastasis

Cancer metastasis is the leading cause of cancer‐related death. It is a complex, inefficient, and multistep process related to poor prognosis and high mortality of patients. Increasing evidence has shown that metabolic programming is a recognized hallmarker of cancer, plays a critical role in cancer metastasis. Metabolism alterations of glucose, lipid, and amino acid provide cancer cells with energy and substances for biosynthesis, maintain biofunctions and significantly affect proliferation, invasion, and metastasis of cancer cells. Tumor microenvironment (TME) is a complex system formed by varieties of cellular and noncellular elements. Nontumor cells in TME also undergo metabolic reprogramming or respond to metabolites to promote migration and invasion of cancer cells. A comprehensive understanding of the regulatory mechanism in metastasis from the metabolic reprogramming aspect is required to develop new therapeutic strategies combatting cancer metastasis. This review illustrates the metabolic reprogramming and interaction of cancer cells and nontumor cells in the TME, and the development of treatment strategies targeting metabolism alterations.

Targeting lactate metabolism and glycolytic pathways in the tumor microenvironment by natural products: A promising strategy in combating cancer

Anticancer drugs are not purely effective because of their toxicity, side effects, high cost, inaccessibility, and associated resistance. On the other hand, cancer is a complex public health problem that could intelligently adopt different signaling pathways and alter the body's metabolism to escape from the immune system. One of the cancer strategies to metastasize is modifying pH in the tumor microenvironment, ranging between 6.5 and 6.9. As a powerful determiner, lactate is responsible for this acidosis. It is involved in immune stimulation, including innate and adaptive immunity, apoptotic-related factors (Bax/Bcl-2, caspase), and glycolysis pathways (e.g., GLUT-1, PKM2, PFK, HK2, MCT-1, and LDH). Lactate metabolism, in turn, is interconnected with several dysregulated signaling mediators, including PI3K/Akt/mTOR, AMPK, NF-κB, Nrf2, JAK/STAT, and HIF-1α. Because of lactate's emerging and critical role, targeting lactate production and its transporters is important for preventing and managing tumorigenesis. Hence, exploring and developing novel promising anticancer agents to minimize human cancers is urgent. Based on numerous studies, natural secondary metabolites as multi-target alternative compounds with health-promoting properties possess more high effectiveness and low side effects than conventional agents. Besides, the mechanism of multi-targeted natural sources is related to lactate production and cancer-associated cross-talked factors. This review focuses on targeting the lactate metabolism/transporters, and lactate-associated mediators, including glycolytic pathways. Besides, interconnected mediators to lactate metabolism are also targeted by natural products. Accordingly, plant-derived secondary metabolites are introduced as alternative therapies in combating cancer through modulating lactate metabolism and glycolytic pathways.

Current Advancements of Plant-Derived Agents for Triple-Negative Breast Cancer Therapy through Deregulating Cancer Cell Functions and Reprogramming Tumor Microenvironment

Triple-negative breast cancer (TNBC) is defined based on the absence of estrogen, progesterone, and human epidermal growth factor receptor 2 receptors. Currently, chemotherapy is the major therapeutic approach for TNBC patients; however, poor prognosis after a standard chemotherapy regimen is still commonplace due to drug resistance. Abnormal tumor metabolism and infiltrated immune or stromal cells in the tumor microenvironment (TME) may orchestrate mammary tumor growth and metastasis or give rise to new subsets of cancer cells resistant to drug treatment. The immunosuppressive mechanisms established in the TME make cancer cell clones invulnerable to immune recognition and killing, and turn immune cells into tumor-supporting cells, hence allowing cancer growth and dissemination. Phytochemicals with the potential to change the tumor metabolism or reprogram the TME may provide opportunities to suppress cancer metastasis and/or overcome chemoresistance. Furthermore, phytochemical intervention that reprograms the TME away from favoring immunoevasion and instead towards immunosurveillance may prevent TNBC metastasis and help improve the efficacy of combination therapies as phyto-adjuvants to combat drug-resistant TNBC. In this review, we summarize current findings on selected bioactive plant-derived natural products in preclinical mouse models and/or clinical trials with focus on their immunomodulatory mechanisms in the TME and their roles in regulating tumor metabolism for TNBC prevention or therapy.

A Novel Prognostic and Predictive Signature for Lung Adenocarcinoma Derived from Combined Hypoxia and Infiltrating Immune Cell-Related Genes in TCGA Patients

Background

The hypoxia and immune status of the lung adenocarcinoma (LUAD) microenvironment appear to have combined impacts on prognosis. Therefore, deriving a prognostic signature by integrating hypoxia- and immune infiltrating cell-related genes (H&IICRGs) may add value over prognostic indices derived from genes driving either process alone.

Methods

Differentially expressed H&IICRGs (DE-H&IICRGs) were identified in The Cancer Genome Atlas transcriptomic data using limma, CIBERSORT, weighted gene co-expression network analysis, and intersection analysis. A stepwise Cox regression model was constructed to identify prognostic genes and to produce a gene signature based on DE-H&IICRGs. The potential biological functions associated with the gene signature were explored using functional enrichment analysis. The prognostic signature was externally validated in a separate cohort from the Gene Expression Omnibus database.

Results

Five prognostic genes associated with overall survival in LUAD were used in the DE-H&IICRG-based prognostic signature. Patients in the high-risk group had an inferior prognosis, which was validated in an independent external cohort, and had lower expression of most immune checkpoint genes. In multivariate analysis, only risk score and T stage were independent prognostic factors. Differentially expressed genes (DEGs) associated with the risk score were enriched for pathways related to cell cycle, hypoxia regulation, and immune response. TIDE analyses showed that low-risk LUAD patients might also respond better to immunotherapy.

Conclusion

This study establishes and validates a prognostic profile for LUAD patients that combines hypoxia and immune infiltrating cell-related genes. This signature may have clinical application both for prognostication and guiding individualized immunotherapy.

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.

Oncogene-mediated metabolic gene signature predicts breast cancer outcome

Breast cancer remains the second most lethal cancer among women in the United States and triple-negative breast cancer is the most aggressive subtype with limited treatment options. Trop2, a cell membrane glycoprotein, is overexpressed in almost all epithelial cancers. In this study, we demonstrate that Trop2 is overexpressed in triple-negative breast cancer (TNBC), and downregulation of Trop2 delays TNBC cell and tumor growth supporting the oncogenic role of Trop2 in breast cancer. Through proteomic profiling, we discovered a metabolic signature comprised of TALDO1, GPI, LDHA, SHMT2, and ADK proteins that were downregulated in Trop2-depleted breast cancer tumors. The identified oncogene-mediated metabolic gene signature is significantly upregulated in TNBC patients across multiple RNA-expression clinical datasets. Our study further reveals that the metabolic gene signature reliably predicts poor survival of breast cancer patients with early stages of the disease. Taken together, our study identified a new five-gene metabolic signature as an accurate predictor of breast cancer outcome.

Oxygen and metabolic reprogramming in the tumor microenvironment influences metastasis homing

Tumor metastasis is the leading cause of cancer mortality, often characterized by abnormal cell growth and invasion to distant organs. The cancer invasion due to epithelial to mesenchymal transition is affected by metabolic and oxygen availability in the tumor-associated micro-environment. A precise alteration in oxygen and metabolic signaling between healthy and metastatic cells is a substantial probe for understanding tumor progression and metastasis. Molecular heterogeneity in the tumor microenvironment help to sustain the metastatic cell growth during their survival shift from low to high metabolic-oxygen-rich sites and reinforces the metastatic events. This review highlighted the crucial role of oxygen and metabolites in metastatic progression and exemplified the role of metabolic rewiring and oxygen availability in cancer cell adaptation. Furthermore, we have also addressed potential applications of altered oxygen and metabolic networking with tumor type that could be a signature pattern to assess tumor growth and chemotherapeutics efficacy in managing cancer metastasis.

In Vitro Investigations of miR-33a Expression in Estrogen Receptor-Targeting Therapies in Breast Cancer Cells

(1) Background: Increased fatty acid synthesis leads to the aggressive phenotype of breast cancer and renders efficiency of therapeutics. Regulatory microRNAs (miRNAs) on lipid biosynthesis pathways as miR-33a have potential to clarify the exact mechanism. (2) Methods: We determined miR-33a expression levels following exposure of MCF-7 and MDA-MB-231 breast cancer cells to estrogen receptor (ER) activator (estradiol-17β, E2) or anti-estrogens (ICI 182,780, Fulvestrant, FUL) at non-cytotoxic concentrations. We related miR-33a expression levels in the cells to cellular lipid biosynthesis-related pathways through immunoblotting. (3) Results: miR-33a mimic treatment led to significantly downregulation of fatty acid synthase (FASN) in MCF-7 cells but not in MDA-MB-231 cells in the presence of estradiol-17β (E2) or Fulvestrant (FUL). In contrast to the miR-33a inhibitor effect, miR-33a mimic co-transfection with E2 or FUL led to diminished AMP-activated protein kinase α (AMPKα) activity in MCF-7 cells. E2 increases FASN levels in MDA-MB-231 cells regardless of miR-33a cellular levels. miR-33a inhibitor co-treatment suppressed E2-mediated AMPKα activity in MDA-MB-231 cells. (4) Conclusions: The cellular expression levels of miR-33a are critical to understanding differential responses which include cellular energy sensors such as AMPKα activation status in breast cancer cells.

Glucose Metabolism and Glucose Transporters in Breast Cancer

Breast cancer is the most common malignancy in women worldwide and is associated with high mortality rates despite the continuously advancing treatment strategies. Glucose is essential for cancer cell metabolism owing to the Warburg effect. During the process of glucose metabolism, various glycolytic metabolites, such as serine and glycine metabolites, are produced and other metabolic pathways, such as the pentose phosphate pathway (PPP), are associated with the process. Glucose is transported into the cell by glucose transporters, such as GLUT. Breast cancer shows high expressions of glucose metabolism-related enzymes and GLUT, which are also related to breast cancer prognosis. Triple negative breast cancer (TNBC), which is a high-grade breast cancer, is especially dependent on glucose metabolism. Breast cancer also harbors various stromal cells such as cancer-associated fibroblasts and immune cells as tumor microenvironment, and there exists a metabolic interaction between these stromal cells and breast cancer cells as explained by the reverse Warburg effect. Breast cancer is heterogeneous, and, consequently, its metabolic status is also diverse, which is especially affected by the molecular subtype, progression stage, and metastatic site. In this review, we will focus on glucose metabolism and glucose transporters in breast cancer, and we will additionally discuss their potential applications as cancer imaging tracers and treatment targets.

Circ-DONSON Facilitates the Malignant Progression of Gastric Cancer Depending on the Regulation of miR-149-5p/LDHA Axis

Earlier studies have shown that circular RNA (circRNA) expression is closely related to the malignant progression of cancer, but the role of circ-DONSON in gastric cancer (GC) has not been fully elucidated. The expression of circ-DONSON, miR-149-5p and lactate dehydrogenase A (LDHA) was measured via qRT-PCR. CCK8 assay was used to assess cell viability, and colony formation assay was performed to detect the number of colonies and the radiosensitivity of cells. Besides, flow cytometry, transwell assay and tube formation assay were employed to determine cell apoptosis, migration, invasion and angiogenesis. Western blot analysis was used to assess the protein expression. The interaction between miR-149-5p and circ-DONSON or LDHA was confirmed by dual-luciferase reporter assay. The influence of circ-DONSON on GC tumor growth in vivo was explored through constructing mice xenograft models. Our results suggested that circ-DONSON was highly expressed in GC tissues and cells. Loss-functional assay results confirmed that silenced circ-DONSON could inhibit the proliferation, metastasis and angiogenesis, while enhance the apoptosis and radiosensitivity of GC cells. In terms of mechanism, circ-DONSON could sponge miR-149-5p, which could target LDHA in GC. MiR-149-5p inhibitor or LDHA overexpression could reverse the suppression effect of circ-DONSON knockdown on GC progression. Additionally, our results also suggested that circ-DONSON silencing could restrain the tumor growth of GC in vivo. These results demonstrated that circ-DONSON could facilitate GC progression by increasing LDHA expression via sponging miR-149-5p, indicating that circ-DONSON might be a novel biomarker for GC treatment.

Energy Metabolic Plasticity of Colorectal Cancer Cells as a Determinant of Tumor Growth and Metastasis

Metabolic plasticity is the ability of the cell to adjust its metabolism to changes in environmental conditions. Increased metabolic plasticity is a defining characteristic of cancer cells, which gives them the advantage of survival and a higher proliferative capacity. Here we review some functional features of metabolic plasticity of colorectal cancer cells (CRC). Metabolic plasticity is characterized by changes in adenine nucleotide transport across the outer mitochondrial membrane. Voltage-dependent anion channel (VDAC) is the main protein involved in the transport of adenine nucleotides, and its regulation is impaired in CRC cells. Apparent affinity for ADP is a functional parameter that characterizes VDAC permeability and provides an integrated assessment of cell metabolic state. VDAC permeability can be adjusted via its interactions with other proteins, such as hexokinase and tubulin. Also, the redox conditions inside a cancer cell may alter VDAC function, resulting in enhanced metabolic plasticity. In addition, a cancer cell shows reprogrammed energy transfer circuits such as adenylate kinase (AK) and creatine kinase (CK) pathway. Knowledge of the mechanism of metabolic plasticity will improve our understanding of colorectal carcinogenesis.

HPIP protooncogene differentially regulates metabolic adaptation and cell fate in breast cancer cells under glucose stress via AMPK and RNF2 dependent pathways

While cancer cells rewire metabolic pathways to sustain growth and survival under metabolic stress in solid tumors, the molecular mechanisms underlying these processes remain largely unknown. In this study, cancer cells switched from survival to death during the early to late phases of metabolic stress by employing a novel signaling switch from AMP activated protein kinase (AMPK)-Forkhead box O3 (FOXO3a)-hematopoietic PBX1-interacting protein (HPIP) to the ring finger protein 2 (RNF2)-HPIP-ubiquitin (Ub) pathway. Acute metabolic stress induced proto-oncogene HPIP expression in an AMPK-FOXO3a-dependent manner in breast cancer (BC) cells. HPIP depletion reduced cell survival and tumor formation in mouse xenografts, which was accompanied by diminished intracellular ATP levels and increased apoptosis in BC cells in response to metabolic (glucose) stress. Glutamine flux (¹³C-labeled) analysis further suggested that HPIP rewired glutamine metabolism by controlling the expression of the solute carrier family 1 member 5 (SLC1A5) and glutaminase (GLS) genes by acting as a coactivator of MYC to ensure cell survival upon glucose deprivation. However, in response to chronic glucose stress, HPIP was ubiquitinated by the E3-Ub ligase, RNF2, and was concomitantly degraded by the proteasome-mediated pathway, ensuring apoptosis. In support of these data, clinical analyses further indicated that elevated levels of HPIP correlated with AMPK activation in BC. Taken together, these data suggest that HPIP is a signal coordinator during metabolic stress and thus serves as a potential therapeutic target in BC.

Epigenetics of Triple-negative breast cancer via natural compounds

Triple-negative breast cancer (TNBC) is a highly resistant, lethal, and metastatic sub-division of breast carcinoma, characterized by the deficiency of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). In women, TNBC shows a higher aggressive behavior with poor patient prognosis and a higher recurrence rate during reproductive age. TNBC is defined by the presence of epithelial-to-mesenchymal-transition (EMT), which shows a significant role in cancer progression. At the epigenetic level, TNBC is characterized by epigenetic signatures, such as DNA methylation, histone remodeling, and a host of miRNA, MiR-193, LncRNA, HIF-2α, eEF2K, LIN9/NEK2, IMP3, LISCH7/TGF-β1, GD3s and KLK12 mediated regulation. These modifications either are silenced or activate the necessary genes that are prevalent in TNBC. The review is based on epigenetic mediated mechanistic changes in TNBC. Furthermore, Thymoquinone (TQ), Regorafenib, Fangjihuangqi decoction, Saikosaponin A, and Huaier, etc., are potent antitumor natural compounds extensively reported in the literature. Further, the review emphasizes the role of these natural compounds in TNBC and their possible epigenetic targets, which can be utilized as a potential therapeutic strategy in treatment of TNBC.

Local production of lactate, ribose phosphate, and amino acids within human triple-negative breast cancer

BACKGROUND

Upregulated glucose metabolism is a common feature of tumors. Glucose can be broken down by either glycolysis or the oxidative pentose phosphate pathway (oxPPP). The relative usage within tumors of these catabolic pathways remains unclear. Similarly, the extent to which tumors make biomass precursors from glucose, versus take them up from the circulation, is incompletely defined.

METHODS

We explore human triple negative breast cancer (TNBC) metabolism by isotope tracing with [1,2-13C]glucose, a tracer that differentiates glycolytic versus oxPPP catabolism and reveals glucose-driven anabolism. Patients enrolled in clinical trial NCT03457779 and received IV infusion of [1,2-13C]glucose during core biopsy of their primary TNBC. Tumor samples were analyzed for metabolite labeling by liquid chromatography-mass spectrometry (LC-MS). Genomic and proteomic analyses were performed and related to observed metabolic fluxes.

FINDINGS

TNBC ferments glucose to lactate, with glycolysis dominant over the oxPPP. Most ribose phosphate is nevertheless produced by oxPPP. Glucose also feeds amino acid synthesis, including of serine, glycine, aspartate, glutamate, proline and glutamine (but not asparagine). Downstream in glycolysis, tumor pyruvate and lactate labeling exceeds that found in serum, indicating that lactate exchange via monocarboxylic transporters is less prevalent in human TNBC compared with most normal tissues or non-small cell lung cancer.

CONCLUSIONS

Glucose directly feeds ribose phosphate, amino acid synthesis, lactate, and the TCA cycle locally within human breast tumors.