Hypoxia promotes the growth and metastasis of ovarian cancer cells by suppressing ferroptosis via upregulating SLC2A12.

BACKGROUND: Ovarian cancer has been a worldwide health burden for women and its progression is highly hypoxia-independent. Here, we investigated the exact mechanisms by which hypoxia contributes to the malignant progression of ovarian cancer. METHOD: MTT, transwell, colony formation, and scratch wound healing assays were carried out for cellular functions. The underlying mechanism by which hypoxia functions was explored by RNA-seq, enrichment analysis, western blotting, qRT-PCR, flow cytometry, ChIP, luciferase reporter, and ELISA. Finally, animal experiments including the xenograft model and tumor metastasis model were constructed to validate the role of SLC2A12 in vivo. RESULTS: Hypoxia treatment promoted the cell proliferation, mobility, and colony growth abilities of the two ovarian cancer cell lines HO-8910 and A2780. RNA-seq and enrichment analysis showed that SLC2A12 was hyper-expressed under hypoxia condition and it may be related to glutathione and lipid metabolism. Besides, the expression of SLC2A12 was negatively correlated with overall survival. Hypoxia suppressed ferroptosis by SLC2A12 because silencing SLC2A12 declined the cell viability of HO-8910 and A2780 cells under hypoxia conditions, while the ferroptosis inhibitor ferrostatin-1 (Fer-1) breached that result and upregulated the expression of glutathione peroxidase 4 (GPX4). Moreover, hypoxia increased the expression of hypoxia inducible factor 1 A (HIF-1A), and the accumulated HIF-1A binds to hypoxia inducible factor 1 B (HIF1B) to form HIF-1 complex, then promoted the binding of hypoxic response elements (HRE) to SLC2A12 promoter by HIF-1/HRE signal. Subsequently, SLC2A12 regulated glutathione metabolism and in turn inhibited ferroptosis. The animal experiments indicated that silencing SLC2A12 could significantly inhibit tumor growth and metastasis in vivo. CONCLUSION: Hypoxia promoted ovarian cancer progression by upregulating SLC2A12 and then regulating glutathione metabolism to inhibit ferroptosis.

SLC2A12 of SLC2 Gene Family in Bird Provides Functional Compensation for the Loss of SLC2A4 Gene in Other Vertebrates.

Avian genomes are small and lack some genes that are conserved in the genomes of most other vertebrates including nonavian sauropsids. One hypothesis stated that paralogs may provide biochemical or physiological compensation for certain gene losses; however, no functional evidence has been reported to date. By integrating evolutionary analysis, physiological genomics, and experimental gene interference, we clearly demonstrate functional compensation for gene loss. A large-scale phylogenetic analysis of over 1,400 SLC2 gene sequences identifies six new SLC2 genes from nonmammalian vertebrates and divides the SLC2 gene family into four classes. Vertebrates retain class III SLC2 genes but partially lack the more recent duplicates of classes I and II. Birds appear to have completely lost the SLC2A4 gene that encodes an important insulin-sensitive GLUT in mammals. We found strong evidence for positive selection, indicating that the N-termini of SLC2A4 and SLC2A12 have undergone diversifying selection in birds and mammals, and there is a significant correlation between SLC2A12 functionality and basal metabolic rates in endotherms. Physiological genomics have uncovered that SLC2A12 expression and allelic variants are associated with insulin sensitivity and blood glucose levels in wild birds. Functional tests have indicated that SLC2A12 abrogation causes hyperglycemia, insulin resistance, and high relative activity, thus increasing energy expenditures that resemble a diabetic phenotype. These analyses suggest that the SLC2A12 gene not only functionally compensates insulin response for SLC2A4 loss but also affects daily physical behavior and basal metabolic rate during bird evolution, highlighting that older genes retain a higher level of functional diversification.

Unveiling the functions of five recently characterized lncRNAs in cancer progression.

Numerous studies over the past few decades have shown that RNAs are multifaceted, multifunctional regulators of most cellular processes, contrary to the initial belief that they only act as mediators for translating DNA into proteins. LncRNAs, which refer to transcripts longer than 200nt and lack the ability to code for proteins, have recently been identified as central regulators of a variety of biochemical and cellular processes, particularly cancer. When they are abnormally expressed, they are closely associated with tumor occurrence, metastasis, and tumor staging. Therefore, through searches on Google Scholar, PubMed, and CNKI, we identified five five recently characterized lncRNAs-Lnc-SLC2A12-10:1, LncRNA BCRT1, lncRNA IGFBP4-1, LncRNA PCNAP1, and LncRNA CDC6-that have been linked to the promotion of cancer cell proliferation, invasion, and metastasis. Consequently, this review encapsulates the existing research and molecular underpinnings of these five newly identified lncRNAs across various types of cancer. It suggests that these novel lncRNAs hold potential as independent biomarkers for clinical diagnosis and prognosis, as well as candidates for therapeutic intervention. In parallel, we discuss the challenges inherent in the research on these five newly discovered lncRNAs and look forward to the avenues for future exploration in this field.

Solute carrier family 2 member 12 intervenes in uric acid-induced renal tubular cell injury / 中国组织工程研究

BACKGROUND:In recent years,the incidence of hyperuricemia caused by purine metabolism disorders has been increasing,which can induce inflammatory responses and lead to renal injury. OBJECTIVE:To explore the role and mechanism of solute carrier family 2 member 12(SLC2A12)in hyperuricemia-related renal injury. METHODS:Renal tubular cells(HK2 cells)were divided into five groups:HK2 group,HK2+uric acid group,HK2+uric acid+NC group,HK2+uric acid+siSLC2A12 group,and HK2+uric acid+siSLC2A12+MK-2206 group.HK2 cells were treated with uric acid and transfected with siRNA SLC2A12,followed by MK-2206 treatment to inhibit AKT expression.Cell proliferation was detected by CCK-8 assay.Apoptosis was detected by TUNEL assay.qRT-PCR and western blot assay were used to detect fibrogenic factors as well as activation of the AKT/FOXO3a pathway.The concentrations of inflammatory cytokines were measured by enzyme-linked immunosorbent assay. RESULTS AND CONCLUSION:(1)Uric acid treatment inhibited cell proliferation and promoted cell apoptosis in the HK2+uric acid group compared with the HK2 group.The proliferative ability of cells in the HK2+uric acid+siSLC2A12 group was further decreased and apoptotic cells were further increased compared with the HK2 group.Compared with the HK2+uric acid+siSLC2A12 group,the HK2+uric acid+siSLC2A12+MK-2206 group showed an increase in cell proliferation and a decrease in apoptotic cells.(2)Compared with the HK2 group,the connective tissue growth factor(CTGF),α-smooth muscle actin(α-SMA)and transforming growth factor beta(TGF-β)expressions increased in the HK2+uric acid group;CTGF,α-SMA and TGF-β expression further increased in the HK2+uric acid+siSLC2A12 group.Compared with the HK2+uric acid+siSLC2A12 group,the CTGF,α-SMA and TGF-β expressions decreased.(3)Compared with the HK2 group,the expression of p-AKT,FOXO3a,and p-FOXO3a elevated in the HK2+uric acid group;the expression of p-AKT further increased,while the expression of FOXO3a and p-FOXO3a decreased in the HK2+uric acid+siSLC2A12 group.Compared with the HK2+uric acid+siSLC2A12 group,p-AKT expression decreased;FOXO3a and p-FOXO3a expression increased in the HK2+uric acid+siSLC2A12+MK-2206 group.(4)Compared with the HK2 group,interleukin-6,interleukin-1 β,and tumor necrosis factor α levels increased in the HK2+uric acid group;interleukin-6,interleukin-1 β,and tumor necrosis factor α levels further increased in the HK2+uric acid+siSLC2A12 group.Compared with the HK2+uric acid+siSLC2A12 group,interleukin-6,interleukin-1 β,and tumor necrosis factor α levels diminished in the HK2+uric acid+siSLC2A12+MK-2206 group.(5)These findings indicate that SLC2A12 may protect against hyperuricemia-induced renal injury by counteracting uric acid-induced tubular fibrosis and inflammation through activation of the FOXO3a pathway.

GLUT12 promotes prostate cancer cell growth and is regulated by androgens and CaMKK2 signaling.

Despite altered metabolism being an accepted hallmark of cancer, it is still not completely understood which signaling pathways regulate these processes. Given the central role of androgen receptor (AR) signaling in prostate cancer, we hypothesized that AR could promote prostate cancer cell growth in part through increasing glucose uptake via the expression of distinct glucose transporters. Here, we determined that AR directly increased the expression of SLC2A12, the gene that encodes the glucose transporter GLUT12. In support of these findings, gene signatures of AR activity correlated with SLC2A12 expression in multiple clinical cohorts. Functionally, GLUT12 was required for maximal androgen-mediated glucose uptake and cell growth in LNCaP and VCaP cells. Knockdown of GLUT12 also decreased the growth of C4-2, 22Rv1 and AR-negative PC-3 cells. This latter observation corresponded with a significant reduction in glucose uptake, indicating that additional signaling mechanisms could augment GLUT12 function in an AR-independent manner. Interestingly, GLUT12 trafficking to the plasma membrane was modulated by calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2)-5'-AMP-activated protein kinase (AMPK) signaling, a pathway we previously demonstrated to be a downstream effector of AR. Inhibition of CaMKK2-AMPK signaling decreased GLUT12 translocation to the plasma membrane by inhibiting the phosphorylation of TBC1D4, a known regulator of glucose transport. Further, AR increased TBC1D4 expression. Correspondingly, expression of TBC1D4 correlated with AR activity in prostate cancer patient samples. Taken together, these data demonstrate that prostate cancer cells can increase the functional levels of GLUT12 through multiple mechanisms to promote glucose uptake and subsequent cell growth.

Long non-coding RNA lnc-SLC2A12-10:1 derived from tumor-associated macrophage exosome aggravates the proliferation and invasion of breast cancer cells through miR-296-5p / 中华内分泌外科杂志

Objective:To investigate the effect of the mechanism of lnc-SLC2A12-10:1 derived from tumor-associated macrophages (TAMs) exosomes on the proliferation and invasion of breast cancer (BC) cells.Methods:GEO microarray analysis was used to screen out the differentially expressed lnc-SLC2A12-10:1 in BC. qRT-PCR was performed to determine the expression level of lnc-SLC2A12-10:1 and miR-296-5p in tissue and cells. Then TAMs and exosomes were isolated. After, interfering the expression level of lnc-SLC2A12-10:1 in exosomes and miR-296-5p expression in cells, then cell proliferation and invasion were detected with the help of MTT and Transwell assays.Results:Compared with adjacent tissues, lnc-SLC2A12-10:1 was significantly up-regulated in BC tissues ( t=7.09, P<0.001) . Compared with normal breast cells, the expression of lnc-SLC2A12-10:1 in T47D and MDA-MB-468 cells was significantly up-regulated ( t=9.90, P<0.001) ( t=12.18, P<0.001) . lnc-SLC2A12-10:1 could act as a ceRNA of miR-296-5p. Knockdown of lnc-SLC2A12-10:1 inhibited BC cell proliferation and invasion, miR-296-5p inhibitor promoted BC cell proliferation and invasion, but this effect could be partially rescued by si--lnc-SLC2A12-10:1-Exo (all P<0.05) . Conclusion:lnc-SLC2A12-10:1 derived from TAMs exosomes promotes BC cell proliferation, invasion and thus advance BC progression.