Silencing of Glut1 induces chemoresistance via modulation of Akt/GSK-3β/β-catenin/survivin signaling pathway in breast cancer cells

Interplay between lncRNAs and the PI3K/AKT signaling pathway in the progression of digestive system neoplasms (Review)

Long non‑coding RNA (lncRNA) is a class of non‑coding RNA molecules located in the cytoplasm or nucleus, which can regulate chromosome structure and function by interacting with DNA, RNA, proteins and other molecules; binding to mRNA bases in a complementary manner, affecting the splicing, stabilization, translation and degradation of mRNA; acting as competing endogenous RNA competitively binds to microRNAs to regulate gene expression and participate in the regulation of various vital activities of the body. The PI3K/AKT signalling pathway plays a key role in numerous biological and cellular processes, such as cell proliferation, invasion, migration and angiogenesis. It has been found that the lncRNA/PI3K/AKT axis regulates the expression of cancer‑related genes and thus tumour progression. The abnormal regulation of lncRNA expression in the lncRNA/PI3K/AKT axis is clearly associated with clinicopathological features and plays an important role in regulating biological functions. In the present review, the expression and biological functions of PI3K/AKT‑related lncRNAs both in vitro and in vivo over recent years, were comprehensively summarized and analyzed. Their correlation with clinicopathological features was also evaluated, with the objective of furnishing a solid theoretical foundation for clinical diagnosis and the monitoring of efficacy in digestive system neoplasms. The present review aimed to provide a comprehensive overview of the expression and biological functions of PI3K/AKT‑related lncRNAs in digestive system neoplasms and to assess their correlation with clinicopathological features. This endeavor seeks to establish a solid theoretical foundation for the clinical diagnosis and efficacy monitoring of digestive system tumors.

tRF-Leu reverse breast cancer cells chemoresistance by regulation of BIRC5

OBJECTIVE

Accumulating studies reported the crucial roles of tRFs in tumorigenesis. However, their further mechanisms and clinical values remains unclear. This study aimed at the further investigation of tRF-Leu in breast cancer chemotherapy resistance.

METHODS

The high-throughput sequencing was performed and identified the downregulation of tRF-Leu in MCF7/ADR cells. The function of tRF-Leu in breast cancer cells and breast cancer chemotherapy resistance was investigated in vitro and in vivo, including colony formation assay, CCK-8 assay, transwell assay and apoptosis assay. The binding site of tRF-Leu on BIRC5 was verified by dual-luciferase assay.

RESULTS

tRF-Leu was downregulated in MCF7/ADR cells. Overexpression of tRF-Leu inhibited the migration of breast cancer cells. Furthermore, tRF-Leu could reverse the resistance of MCF7/ADR cells to Adriamycin both in vitro and in vivo. BIRC5 was a target of tRF-Leu, which might be involved in the chemotherapy resistance regulation.

CONCLUSION

We demonstrated that tRF-Leu could inhibit the chemotherapy resistance of breast cancer by targeting BIRC5. These findings might identify new biomarkers of breast cancer therapy and bring new strategies to reverse chemotherapy resistance.

Evaluation of the effect of GSK-3β on liver cancer based on the PI3K/AKT pathway

The PI3K/AKT/GSK-3β signaling pathway plays a pivotal role in numerous physiological and pathological processes, including cell proliferation, apoptosis, differentiation, and metabolic regulation. Aberrant activation of the PI3K/AKT pathway is intricately linked to development of tumor. GSK-3β, belonging to the serine/threonine protein kinase family, is crucial in the pathogenesis of liver cancer. As a key rate-limiting enzyme in the glucose metabolism pathway, GSK-3β significantly impacts the growth, proliferation, metastasis, and apoptosis of liver cancer cells. It is also implicated in chemotherapy resistance. Elevated expression of GSK-3β diminishes the sensitivity of liver cancer cells to chemotherapeutic agents, thereby playing a substantial role in the development of drug resistance. Consequently, targeting of GSK-3β, particularly within the PI3K/AKT signaling pathway, is regarded as a promising therapeutic strategy for liver cancer. The precise identification and subsequent modulation of this pathway represent a substantial potential for innovative clinical interventions in the management of liver cancer.

Multifaceted TGF-β signaling, a master regulator: From bench-to-bedside, intricacies, and complexities

Physiological embryogenesis and adult tissue homeostasis are regulated by transforming growth factor-β (TGF-β), an evolutionarily conserved family of secreted polypeptide factors, acting in an autocrine and paracrine manner. The role of TGF-β in inflammation, fibrosis, and cancer is complex and sometimes even contradictory, exhibiting either inhibitory or promoting effects depending on the stage of the disease. Under pathological conditions, especially fibrosis and cancer, overexpressed TGF-β causes extracellular matrix deposition, epithelial-mesenchymal transition, cancer-associated fibroblast formation, and/or angiogenesis. In this review article, we have tried to dive deep into the mechanism of action of TGF-β in inflammation, fibrosis, and carcinogenesis. As TGF-β and its downstream signaling mechanism are implicated in fibrosis and carcinogenesis blocking this signaling mechanism appears to be a promising avenue. However, targeting TGF-β carries substantial risk as this pathway is implicated in multiple homeostatic processes and is also known to have tumor-suppressor functions. There is a need for careful dosing of TGF-β drugs for therapeutic use and patient selection.

Histone acetylation: a key determinant of acquired cisplatin resistance in cancer

Cisplatin is an alkylating class of chemotherapeutic drugs used to treat cancer patients. However, cisplatin fails in long-term treatment, and drug resistance is the primary reason for tumor recurrence. Hence, understanding the mechanism of acquirement of chemoresistance is essential for developing novel combination therapeutic approaches. In this study, in vitro cisplatin-resistant cancer cell line models were developed. Gene ontology and GSEA of differentially expressed genes between parental and resistant cells suggest that PI3K-AKT signaling, central carbon metabolism, and epigenetic-associated phenomenon alter in cisplatin-resistant cells. Further, the data showed that increased glucose transport, alteration in the activity of histone-modifying enzymes, and acetyl-CoA levels in resistant cells paralleled an increase in global histone acetylation. Enrichment of histone acetylation on effectors of PI3K-AKT and glycolysis pathway provides evidence of epigenetic regulation of the key molecules in drug resistance. Moreover, cisplatin treatment to resistant cells showed no significant changes in histone acetylation marks since drug treatment alters cell epigenome. In continuation, targeting PI3K-AKT signaling and glycolysis leads to alteration in histone acetylation levels and re-sensitization of resistant cells to chemo-drug. The data provide evidence of histone acetylation's importance in regulating pathways and cisplatin-resistant cells' cell survival. Our study paves the way for new approaches for developing personalized therapies in affecting metabolic pathways and epigenetic changes to achieve better outcomes for targeting drug-resistant cells.

OBHS Drives Abnormal Glycometabolis Reprogramming via GLUT1 in Breast Cancer

Due to the poor metabolic conditions fomenting the emergence of the Warburg effect (WE) phenotype, abnormal glycometabolism has become a unique and fundamental research topic in the field of tumor biology. Moreover, hyperglycemia and hyperinsulinism are associated with poor outcomes in patients with breast cancer. However, there are a few studies on anticancer drugs targeting glycometabolism in breast cancer. We hypothesized that Oxabicycloheptene sulfonate (OBHS), a class of compounds that function as selective estrogen receptor modulators, may hold potential in a therapy for breast cancer glycometabolism. Here, we evaluated concentrations of glucose, glucose transporters, lactate, 40 metabolic intermediates, and glycolytic enzymes using an enzyme-linked immunosorbent assay, Western blotting, and targeted metabolomic analysis in, in vitro and in vivo breast cancer models. OBHS significantly inhibited the expression of glucose transporter 1 (GLUT1) via PI3K/Akt signaling pathway to suppress breast cancer progression and proliferation. Following an investigation of the modulatory effect of OBHS on breast cancer cells, we found that OBHS suppressed the glucose phosphorylation and oxidative phosphorylation of glycolytic enzymes, leading to the decreased biological synthesis of ATP. This study was novel in highlighting the role of OBHS in the remodeling of tumor glycometabolism in breast cancer, and this is worth further investigation of breast cancer in clinical trials.

Correlation between the Warburg effect and progression of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is ineligible for hormonal therapy and Her-2-targeted therapy due to the negative expression of the estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2. Although targeted therapy and immunotherapy have been shown to attenuate the aggressiveness of TNBC partially, few patients have benefited from them. The conventional treatment for TNBC remains chemotherapy. Chemoresistance, however, impedes therapeutic progress over time, and chemotherapy toxicity increases the burden of cancer on patients. Therefore, introducing more advantageous TNBC treatment options is a necessity. Metabolic reprogramming centered on glucose metabolism is considered a hallmark of tumors. It is described as tumor cells tend to convert glucose to lactate even under normoxic conditions, a phenomenon known as the Warburg effect. Similar to Darwinian evolution, its emergence is attributed to the selective pressures formed by the hypoxic microenvironment of pre-malignant lesions. Of note, the Warburg effect does not disappear with changes in the microenvironment after the formation of malignant tumor phenotypes. Instead, it forms a constitutive expression mediated by mutations or epigenetic modifications, providing a robust selective survival advantage for primary and metastatic lesions. Expanding evidence has demonstrated that the Warburg effect mediates multiple invasive behaviors in TNBC, including proliferation, metastasis, recurrence, immune escape, and multidrug resistance. Moreover, the Warburg effect-targeted therapy has been testified to be feasible in inhibiting TNBC progression. However, not all TNBCs are sensitive to glycolysis inhibitors because TNBC cells flexibly switch their metabolic patterns to cope with different survival pressures, namely metabolic plasticity. Between the Warburg effect-targeted medicines and the actual curative effect, metabolic plasticity creates a divide that must be continuously researched and bridged.

TGF-β signaling in the tumor metabolic microenvironment and targeted therapies

Transforming growth factor-β (TGF-β) signaling has a paradoxical role in cancer progression, and it acts as a tumor suppressor in the early stages but a tumor promoter in the late stages of cancer. Once cancer cells are generated, TGF-β signaling is responsible for the orchestration of the immunosuppressive tumor microenvironment (TME) and supports cancer growth, invasion, metastasis, recurrence, and therapy resistance. These progressive behaviors are driven by an “engine” of the metabolic reprogramming in cancer. Recent studies have revealed that TGF-β signaling regulates cancer metabolic reprogramming and is a metabolic driver in the tumor metabolic microenvironment (TMME). Intriguingly, TGF-β ligands act as an “endocrine” cytokine and influence host metabolism. Therefore, having insight into the role of TGF-β signaling in the TMME is instrumental for acknowledging its wide range of effects and designing new cancer treatment strategies. Herein, we try to illustrate the concise definition of TMME based on the published literature. Then, we review the metabolic reprogramming in the TMME and elaborate on the contribution of TGF-β to metabolic rewiring at the cellular (intracellular), tissular (intercellular), and organismal (cancer-host) levels. Furthermore, we propose three potential applications of targeting TGF-β-dependent mechanism reprogramming, paving the way for TGF-β-related antitumor therapy from the perspective of metabolism.

Relationship between metabolic reprogramming and drug resistance in breast cancer

Breast cancer is the leading cause of cancer death in women. At present, chemotherapy is the main method to treat breast cancer in addition to surgery and radiotherapy, but the process of chemotherapy is often accompanied by the development of drug resistance, which leads to a reduction in drug efficacy. Furthermore, mounting evidence indicates that drug resistance is caused by dysregulated cellular metabolism, and metabolic reprogramming, including enhanced glucose metabolism, fatty acid synthesis and glutamine metabolic rates, is one of the hallmarks of cancer. Changes in metabolism have been considered one of the most important causes of resistance to treatment, and knowledge of the mechanisms involved will help in identifying potential treatment deficiencies. To improve women's survival outcomes, it is vital to elucidate the relationship between metabolic reprogramming and drug resistance in breast cancer. This review analyzes and investigates the reprogramming of metabolism and resistance to breast cancer therapy, and the results offer promise for novel targeted and cell-based therapies.

Dezocine relieves the postoperative hyperalgesia in rats through suppressing the hyper-action of Akt1/GSK-3β pathway

The relieving role of dezocine in pain after surgery was previously reported, while the potential mechanism was not completely clear. Therefore, the current research probed into the regulatory mechanism of dezocine in pain after surgery. A postoperative pain model was established by performing plantar incision surgery on the juvenile Sprague-Dawley rats. After the rats were treated with dezocine or SC79 (Akt1 activator), the paw withdrawal threshold and paw withdrawal latency of rats were detected to evaluate the mechanical allodynia and thermal hyperalgesia. After the plantar tissue, dorsal root ganglions, and spinal cord of rats were collected, the expressions of Akt1, p-Akt1, GSK-3β, and p-GSK-3β in the tissues were determined by western blot to evaluate the activation state of the Akt1/GSK-3β pathway. After surgery, the paw withdrawal threshold and paw withdrawal latency of rats were lessened, whereas the ratios of p-Akt1/Akt1 and p-GSK-3β/GSK-3β were augmented in rat plantar tissue, dorsal root ganglions, and spinal cord. After treatment with dezocine alone, the paw withdrawal threshold and paw withdrawal latency of postoperative rats were elevated, but ratios of p-Akt1/Akt1 and p-GSK-3β/GSK-3β were reduced. After co-treatment with dezocine and SC79, SC79 reversed the effects of dezocine on elevating the paw withdrawal threshold and paw withdrawal latency, and reducing the ratios of p-Akt1/Akt1 and p-GSK-3β/GSK-3β in postoperative rats. Dezocine ameliorated the postoperative hyperalgesia in rats via repressing the hyper-action of Akt1/GSK-3β pathway.

Circ_0001955 plays a carcinogenic role in breast cancer via positively regulating GLUT1 via decoying miR-1299

BACKGROUND

Breast cancer is widespread in females. The role of circular RNA (circRNA) in breast cancer has aroused much attention. However, the function of several circRNAs remain unclear. The aim of our study was to determine the role of circ_0001955 in breast cancer.

METHODS

Quantitative real-time PCR (qPCR) and western blot was employed for expression analysis of circ_0001955, miR-1299 and glucose transporter 1 (GLUT1). Cell functions including proliferation, apoptosis, migration, invasion and angiogenesis, were assessed using EdU, flow cytometry, transwell and tube formation assays. Glycolysis metabolism was assessed according to glucose consumption, lactate production and ATP content. Dual-luciferase reporter assay and RIP assay were utilized to validate the binding between miR-1299 and circ_0001955 or GLUT1. The effects of circ_0001955 in vivo were observed by animal study.

RESULTS

Upregulation of circ_0001955 was detected in breast cancer. Knockdown of circ_0001955 inhibited breast cancer cell proliferation, migration, invasion, angiogenesis and glycolysis. MiR-1299 was a target of circ_0001955, and its repression reversed the effects of circ_0001955 knockdown. Moreover, circ_0001955 targeted miR-1299 to positively regulate GLUT1 expression. GLUT1 overexpression reversed the effects of miR-1299 enrichment. GLUT1 knockdown was verified to block tumor growth in vivo.

CONCLUSIONS

Circ_0001955 was found to promote breast cancer malignant development via targeting of the miR-1299/GLUT1 pathway, which contributes to our understanding of the pathogenesis of breast cancer.

Caspase-3/Treg and PI3K/AKT/mTOR pathway is involved in Liver Ischemia Reperfusion Injury (IRI) protection by everolimus

Ischemia-reperfusion injury (IRI) of the liver is a severe complication that can follow hemorrhagic shock and liver surgery. Regulatory T cells (Treg) show the potential of improving outcomes of IRI. Everolimus is an mTOR inhibitor used in liver transplantation and the treatment of tumor patients through PI3K/AKT/mTOR pathway. The present study was designed to investigate the efficacy and mechanism of everolimus on Treg for the treatment of IRI. Hepatocytes were exposed to H₂O₂ and hypoxic conditions to investigate the effects of everolimus on reactive oxygen species ROS-induced and H/R-induced injury in vitro. The effects of everolimus on liver IRI were investigated in a warm ischemia liver model in vivo. Our results indicate that everolimus markedly protected liver IRI in vivo and vitro. Furthermore, everolimus increased the levels of phospho- (p-)AKT, p-mTOR but not p-GSK following IRI. Taken together, our data showed that everolimus protected against IRI via regulation of caspase-3/Treg and the PI3K/AKT/mTOR signalling pathway, which provides new insight into the treatment of liver IRI.

Antiproliferative and antimetastatic characterization of an exo-heterocyclic androstane derivative against human breast cancer cell lines

Cancer in general, and specifically gynaecological neoplasms, represents a major public health issue worldwide. Based on the effect of sex hormones on breast tumorigenesis and prognosis, as well as on the development of breast cancer metastases, modification of the steroid skeleton is a hotspot of research for novel anticancer agents. Numerous recent studies support that minor modifications of the androstane skeleton yield potent antiproliferative and antimetastatic drug candidates. The aim of the present study was to assess the antitumor and antimetastatic properties, as well as the mechanism of action of a D-ring-modified exo-heterocyclic androstadiene derivative named 17APAD. The test compound was found to be highly selective towards human breast cancer-derived cell lines (MCF-7, T47D, MDA-MB-361, MDA-MB-231) compared to non-cancerous fibroblast cells (NIH/3T3), and exerted superior effect compared to the clinically applied reference drug cisplatin. Changes in MCF-7- and MDA-MB-231 cell morphology and membrane integrity induced by the test substance were assessed by fluorescent double staining. Cell cycle disturbances were analyzed by flow cytometry, and concentration-dependent alterations were detected on breast cancer cell lines. Mitochondrial apoptosis induced by the test compound was demonstrated by JC-1 staining. Inhibitory effects on metastasis formation, including the inhibition of migration, invasion and intravasation were investigated in 2D and 3D models. Significant anti-migratory and anti-invasive effects on MCF-7 and MDA-MB-231 cells were detected after 24 h exposure in 2D wound healing and Boyden-chamber assays. The anti-intravasative properties of 17APAD were evident after 4 h of incubation in a co-culture 3D circular chemorepellent-induced defects (CCID) assay, and the level of inhibition at concentrations ≥2 µM was comparable to that exerted by the focal adhesion kinase inhibitor defactinib. Single cell mass cytometry revealed that chemosensitive subpopulations of MDA-MB-231 cells engaged to apoptosis were less positive for EGFR, CD274, and CD326, while the percentage of cells positive for GLUT1, MCT4, Pan-Keratin, CD66(a,c,e), Galectin-3 and TMEM45A increased in response to 17APAD treatment. Finally, the novel androstane analogue 17APAD had an outstanding inhibitory effect on tumour growth in the 4T1 orthotopic murine breast cancer model in vivo after 2 weeks of intraperitoneal administration. These findings support that substitution of the androsta-5,16-diene framework with a N-containing heterocyclic moiety at C17 position yields a molecular entity rational to be considered for design and synthesis of novel, effective antitumor agents, and 17APAD is worth further investigation as a promising anticancer drug candidate.

TRIM37 Mediates Chemoresistance and Maintenance of Stemness in Pancreatic Cancer Cells via Ubiquitination of PTEN and Activation of the AKT-GSK-3β-β-Catenin Signaling Pathway

Purpose

The tripartite motif-containing family member TRIM37 is involved in a number of important biological and pathological processes, and it has recently been shown to be an essential regulator of protein ubiquitination and a contributor to tumorigenesis. We previously showed that TRIM37 is overexpressed in and promotes the proliferation and invasion of pancreatic cancer (PC).

Methods

Sphere formation, flow cytometric, qRT-PCR, western blot, colony formation, EdU incorporation, mouse xenograft model, TUNEL and IHC assays were performed to detect the role of TRIM37 in stemness and chemoresistance of PC in vitro and in vivo. Bioinformatics analysis and dual-luciferase reporter assays were used to determine which intracellular pathways might mediate the effects of TRIM37 in PC cells. Immunofluorescent(IF) staining, co-immunoprecipitation(CO-IP), protein stability and ubiquitination assays were performed to investigate the relationship between TRIM37 and PTEN.

Results

TRIM37 modulates the ubiquitination and degradation of the tumor suppressor phosphatase and tensin homolog (PTEN), which negatively regulates the AKT–GSK-3β–β-catenin signaling pathway, thereby sustaining aberrant activation of PC cells. High expression of TRIM37 combined with low expression of PTEN correlates with poor survival of PC patients.

Conclusions

Collectively, our results suggest that inhibition of the TRIM37–AKT–GSK-3β–β-catenin axis may be a promising strategy for treatment of PC.

PI3K/AKT pathway as a key link modulates the multidrug resistance of cancers

Multidrug resistance (MDR) is the dominant challenge in the failure of chemotherapy in cancers. Phosphatidylinositol 3-kinase (PI3K) is a lipid kinase that spreads intracellular signal cascades and regulates a variety of cellular processes. PI3Ks are considered significant causes of chemoresistance in cancer therapy. Protein kinase B (AKT) is also a significant downstream effecter of PI3K signaling, and it modulates several pathways, including inhibition of apoptosis, stimulation of cell growth, and modulation of cellular metabolism. This review highlights the aberrant activation of PI3K/AKT as a key link that modulates MDR. We summarize the regulation of numerous major targets correlated with the PI3K/AKT pathway, which is further related to MDR, including the expression of apoptosis-related protein, ABC transport and glycogen synthase kinase-3 beta (GSK-3β), synergism with nuclear factor kappa beta (NF-κB) and mammalian target of rapamycin (mTOR), and the regulation of glycolysis.

Long noncoding RNA lncARSR confers resistance to Adriamycin and promotes osteosarcoma progression

One of the significant challenges for chemotherapy is the appearance of resistance to compounds. Although several signaling pathways have been implicated in the development of Adriamycin (ADM) resistance, mechanisms involved in ADM-resistant osteosarcoma progression remain unknown. The present study attempted to illustrate the role of long noncoding RNA ARSR (lncARSR) in the development of adapted ADM resistance. We found lncARSR overexpressed in the Adriamycin-resistant cell lines U2OS/ADM and MG63/ADM, accompanied with acquired multidrug resistance against to paclitaxel and cisplatin. Overexpression of lncARSR triggered rhodamine 123 efflux and survival, as well as the migration of Adriamycin-resistant cells. Inversely, the depletion of lncARSR promoted rhodamine 123 retention and apoptosis, while reducing the motility of ADM-resistant cells. Further investigation revealed that the upregulation of lncARSR enhanced multidrug resistance-associated protein-1 (MRP1), apoptosis inhibitor Survivin, and matrix metalloproteinase-2 (MMP2) through activating AKT. The reduction of lncARSR overcame the resistance to ADM in U2OS/ADM mouse model. The current study gained novel evidence for understanding the mechanisms underlying adaptive ADM resistance and provided rationales to improve clinical outcomes of refractory osteosarcoma.

Dezocine regulates the malignant potential and aerobic glycolysis of liver cancer targeting Akt1/GSK-3β pathway

Background

Due to the “ceiling effect” of respiratory depression and the non-addictiveness, the consumption of dezocine is increasing quickly in the cancer surgery perioperative period for security and comfort reasons in China. Former studies find dezocine inhibits the norepinephrine transporters (NET) and serotonin transporters (SERT) and sigma-1opioid receptors. Given the complexity of the molecular mechanism, the effect of dezocine on tumor cells need to be studied. In this study, we investigated the effect of dezocine on HepG2 and Hep 3B liver cancer cell lines growth and glycolysis, and the molecular mechanisms behind.

Methods

HepG2 and Hep 3B cells viability and migration were measured by CCK8, Wound healing and transwell assay, Extracellular acidification rate (ECAR) was used to index the aerobic glycolysis of liver cancer cells and western blot analysis showed protein expression levels in the cells. SC79, an agonist of Akt, and the siRNA silence of Akt1 aimed to regulate Akt1 activity and expression in the reverse experiments.

Results

Dezocine played opposite roles in HepG2 and Hep 3B cells viability and migration in a concentration-dependent manner (P<0.01). Dezocine has diverse effects on aerobic glycolysis and adjusts the serine/threonine kinase 1 (Akt1)-glycogen synthase kinase-3β (GSK-3β) pathway. The effects of SC79 and the siRNA silence of Akt1 could reverse the effects of dezocine on HepG2 and Hep 3B cells.

Conclusions

As an analgesic drug widely used in clinical practice, dezocine play reversed roles on HepG2 and Hep 3B cells viability and migration targeting Akt1/GSK-3β pathway then the glycolysis in a concentration-dependent manner.

Targeting Glucose Transporters for Breast Cancer Therapy: The Effect of Natural and Synthetic Compounds

Reprogramming of cellular energy metabolism is widely accepted to be a cancer hallmark. The deviant energetic metabolism of cancer cells-known as the Warburg effect-consists in much higher rates of glucose uptake and glycolytic oxidation coupled with the production of lactic acid, even in the presence of oxygen. Consequently, cancer cells have higher glucose needs and thus display a higher sensitivity to glucose deprivation-induced death than normal cells. So, inhibitors of glucose uptake are potential therapeutic targets in cancer. Breast cancer is the most commonly diagnosed cancer and a leading cause of cancer death in women worldwide. Overexpression of facilitative glucose transporters (GLUT), mainly GLUT1, in breast cancer cells is firmly established, and the consequences of GLUT inhibition and/or knockout are under investigation. Herein we review the compounds, both of natural and synthetic origin, found to interfere with uptake of glucose by breast cancer cells, and the consequences of interference with that mechanism on breast cancer cell biology. We will also present data where the interaction with GLUT is exploited in order to increase the efficiency or selectivity of anticancer agents, in breast cancer cells.

Glut 1 in Cancer Cells and the Inhibitory Action of Resveratrol as A Potential Therapeutic Strategy

An important hallmark in cancer cells is the increase in glucose uptake. GLUT1 is an important target in cancer treatment because cancer cells upregulate GLUT1, a membrane protein that facilitates the basal uptake of glucose in most cell types, to ensure the flux of sugar into metabolic pathways. The dysregulation of GLUT1 is associated with numerous disorders, including cancer and metabolic diseases. There are natural products emerging as a source for inhibitors of glucose uptake, and resveratrol is a molecule of natural origin with many properties that acts as antioxidant and antiproliferative in malignant cells. In the present review, we discuss how GLUT1 is involved in the general scheme of cancer cell metabolism, the mechanism of glucose transport, and the importance of GLUT1 structure to understand the inhibition process. Then, we review the current state-of-the-art of resveratrol and other natural products as GLUT1 inhibitors, focusing on those directed at treating different types of cancer. Targeting GLUT1 activity is a promising strategy for the development of drugs aimed at treating neoplastic growth.

TRIM11 promotes proliferation and glycolysis of breast cancer cells via targeting AKT/GLUT1 pathway

Background: Tripartite motif-containing protein 11 (TRIM11) is one of the E3 ubiquitin ligases, which is upregulated in several human tumors. Meanwhile, the detailed function of TRIM11 remains unclear in breast cancer cells.

Purpose: The purpose of the present study is to analyze the biological function of TRIM11 and identify its potential signaling pathway in breast cancer cells.

Patients and methods: Thirty five pairs of breast cancer specimens and adjacent-matched noncancerous samples were used to analyse the expression profile of TRIM11. RNA interference was utilized to silence TRIM11 in three breast cancer cell lines (T47D, ZR7530, and BT474) respectively. Meanwhile, overexpression of TRIM11 was induced in one breast cancer cells (MDA-MB-231) by using Lentiviral vector. Moreover, the AKT inhibitor (MK-2206) was used to determine the correlation between TRIM11 and AKT in breast cancer cells.

Results: Our results indicated that TRIM11 was increased in breast cancer tissues. Moreover, TRIM11 was a pro-proliferation regulator in breast cancer cells and participated in the metabolism of glycolysis. Importantly, our results demonstrated that TRIM11 was involved in the AKT/GLUT1 signaling pathway in breast cancer cells.

Conclusion: Present research not only gained a deep understanding of the biological function of TRIM11 but also provided evidences to indicate its possible signaling pathway in breast cancer cells.

Hinokitiol suppresses growth of B16 melanoma by activating ERK/MKP3/proteosome pathway to downregulate survivin expression

Metastasis is the major cause of treatment failure in patients with cancer. Hinokitiol, a metal chelator derived from natural plants, has anti-inflammatory and antioxidant activities as well as anticancer effects. We investigated the potential anticancer effects of hinokitiol in metastatic melanoma cell line B16-F10. Exposure of the melanoma B16-F10 cells to hinokitiol significantly inhibited colony formation and cell viability in a time and concentration-dependent manner. The hinokitiol-treated cells exhibited apoptotic features in morphological assay. Results from Western blot and immunoprecipitation showed that hinokitiol treatment decreased survivin protein levels and increased suvivin ubiquitination. Pretreatment with proteosome inhibitors effectively prevented hinokitiol-induced decrease in survivin expression, implying that ubiquitin/proteosome pathway involved in hinokitiol-reduced survivin expression. Hinokitiol rapidly induced ERK phosphorylation followed by a sustained dephosphorylation, which accompanied with an increase in expression of tumor suppressor MKP-3 (mitogen-activated protein kinase phosphatase-3). Inhibition of hinokitiol-induced ERK activation by MEK inhibitor U0126 completely blocked expression of MKP-3. More importantly, inhibition of MKP-3 activity by NSC 95397 significantly inhibited hinokitiol-induced ERK dephosphorylation, ubiquitination and downregulation of survivin. These results suggested that hinokitiol inhibited growth of B16-F10 melanoma through downregulation of survivin by activating ERK/MKP-3/proteosome pathway. Hinokitiol-inhibition of survivin may be a novel and potential approach for melanoma therapy. Hinokitiol can be useful for developing therapeutic agent for melanoma.

GSK-3β Inhibitor Alsterpaullone Attenuates MPP+-Induced Cell Damage in a c-Myc-Dependent Manner in SH-SY5Y Cells

Mitochondrial dysfunction plays significant roles in the pathogenesis of Parkinson’s Disease (PD). The inactivation of c-Myc, a down-stream gene of Wnt/β-catenin signaling, may contribute to the mitochondria dysfunction. Inhibition of glycogen synthase kinase 3β (GSK-3β) with Alsterpaullone (Als) can activate the down-stream events of Wnt signaling. Here, we investigated the protective roles of Als against MPP⁺-induced cell apoptosis in SH-SY5Y cells. The data showed that Als effectively rescued c-Myc from the MPP⁺-induced decline via Wnt signaling. Furthermore, Als protected SH-SY5Y cells from the MPP⁺-induced mitochondrial fission and cell apoptosis. However, the protective roles of Als were lost under β-catenin-deficient conditions. These findings indicate that Als, a GSK-3β inhibitor, attenuated the MPP⁺-induced mitochondria-dependent apoptotic via up-regulation of the Wnt signaling.

miR372 Promotes Progression of Liver Cancer Cells by Upregulating erbB-2 through Enhancement of YB-1

MicroRNAs are known to be involved in carcinogenesis. Recently, microRNA-372 (miR372) has been proven to play a substantial role in several human cancers, but its functions in liver cancer remain unclear. Herein, our results demonstrate that miR372 accelerates growth of liver cancer cells in vitro and in vivo. Mechanistically, miR372 enhances expression of Y-box-binding protein 1 (YB-1) by targeting for phosphatase and tensin homolog (PTEN) directly and consequently promotes phosphorylation of YB-1 via HULC looping dependent on ERK1/2 and PTEN. In particular, HULC knockdown or PTEN overexpression abrogated this miR372 action. Moreover, miR372 inhibits the degradation of β-catenin dependent on phosphorylation of YB-1 and then enhances the expression and activity of pyruvate kinase M2 isoform (PKM2) by β-catenin-LEF/TCF4 pathway. Furthermore, the loading of LEF/TCF4 on PKM2 promoter region was significantly increased in miR372 overexpressing Hep3B, and thus, glycolytic proton efflux rate (glycoPER) was significantly increased in rLV-miR372 group compared to the rLV group. Moreover, β-catenin knockdown abrogates this function of miR372. Ultimately, miR372 promotes the expression of erbB-2 through PKM2-pH3T11-acetylation on histone H3 lysine 9 (H3K9Ac) pathway. Of significance, both YB-1 knockdown and erbB-2 knockdown abrogate oncogenic action of miR372. Our observations suggest that miR372 promotes liver cancer cell cycle progress by activating cyclin-dependent kinase 2 (CDK2)-cyclin E-P21/Cip1 complex through miR372-YB-1-β-catenin-LEF/TCF4-PKM2-erbB-2 axis. This study elucidates a novel mechanism for miR372 in liver cancer cells and suggests that miR372 can be used as a novel therapeutic target of liver cancer.