Impact of GLUT1 and Ki-67 expression on early‑stage lung adenocarcinoma diagnosed according to a new international multidisciplinary classification

GLUT1 promotes cell proliferation via binds and stabilizes phosphorylated EGFR in lung adenocarcinoma

BACKGROUND

While previous studies have primarily focused on Glucose transporter type 1 (GLUT1) related glucose metabolism signaling, we aim to discover if GLUT1 promotes tumor progression through a non-metabolic pathway.

METHODS

The RNA-seq and microarray data were comprehensively analyzed to evaluate the significance of GLUT1 expression in lung adenocarcinoma (LUAD). The cell proliferation, colony formation, invasion, and migration were used to test GLUT1 's oncogenic function. Co-immunoprecipitation and mass spectrum (MS) were used to uncover potential GLUT1 interacting proteins. RNA-seq, DIA-MS, western blot, and qRT-PCR to probe the change of gene and cell signaling pathways.

RESULTS

We found that GLUT1 is highly expressed in LUAD, and higher expression is related to poor patient survival. GLUT1 knockdown caused a decrease in cell proliferation, colony formation, migration, invasion, and induced apoptosis in LUAD cells. Mechanistically, GLUT1 directly interacted with phosphor-epidermal growth factor receptor (p-EGFR) and prevented EGFR protein degradation via ubiquitin-mediated proteolysis. The GLUT1 inhibitor WZB117 can increase the sensitivity of LUAD cells to EGFR-tyrosine kinase inhibitors (TKIs) Gefitinib.

CONCLUSIONS

GLUT1 expression is higher in LUAD and plays an oncogenic role in lung cancer progression. Combining GLUT1 inhibitors and EGFR-TKIs could be a potential therapeutic option for LUAD treatment.

In vitro and in silico cytotoxic activities of triterpenoids from the leaves of Aralia dasyphylla Miq. and the assessment of their ADMET properties

From the methanol extract of the leaves of Aralia dasyphylla Miq. (Araliaceae), ten triterpenoids including five ursane-type triterpenoids, ursolic acid (1), 3-O-α-l-arabinopyranosyl ursolic acid (2), ursolic acid 28-O-β-D-glucopyranosyl ester (3), 3-O-[β-D-glucopyranosyl (l→3)]-α-L-arabinopyranosyl ursolic acid (4), and matesaponin 1 (5), and five oleanane-type triterpenoids, elatoside E (6), elatoside F (7), 3-O-[β-D-glucopyranosyl (l→3)]-α-L-arabinopyranosyl oleanolic acid (8), 3-O-α-L-arabinopyranosyl oleanolic acid (9) and oleanolic acid 28-O-β-D-glucopyranosyl ester (10) were isolated. Their structures were elucidated based on 1D-, 2D-NMR and ESI-MS spectra as well as by comparison with those reported in the literature. All isolated compounds were evaluated in vitro for their cytotoxic activities against three human cancer cell lines (HepG2, LU-1 and RD) and in silico by molecular docking studies on human glucose transporter 1 (hGLUT1) protein. The triterpenoids 2, 4, 6, 8 and 9 exhibited good growth inhibition of HepG2 and LU-1 cancer cell lines with IC50 values in the range 1.76 - 7.21 (μM). The oleanane type triterpenoid 8 was the highest cytotoxic compound to inhibit all the tested cancer cell lines with IC50 values of 2.73 ± 0.12, 1.76 ± 0.11, 2.63 ± 0.10 μM, respectively. The in silico molecular docking study results showed that compounds 4 and 6 had the highest binding affinity. Compounds 1-10 were evaluated for their in silico ADMET of absorption, distribution, metabolism, excretion and oral toxicity parameters. Compounds 6, 8, 9 and 10 from A. dasyphylla are potential hGLUT1 inhibitors and worth of further investigation for the prevention or treatment of diabetes and cancer.Communicated by Ramaswamy H. Sarma.

GLUT1 and PKM2 may be useful prognostic predictors in patients with non‑small cell lung cancer following curative R0 resection

Lung cancer has a poor prognosis despite recent progresses being made regarding its treatment. In addition, there is a paucity of reliable and independent prognostic predictors for non-small cell lung cancer (NSCLC) following curative resection. Glycolysis is associated with the malignancy and proliferation of cancer cells. Glucose transporter 1 (GLUT1) promotes glucose uptake, whereas pyruvate kinase M2 (PKM2) promotes anaerobic glycolysis. The present study aimed to evaluate the relationship between the expression of GLUT1 and PKM2 and the clinicopathological features of patients with NSCLC, and to identify a reliable prognostic factor for NSCLC following curative resection. Patients with NSCLC who underwent curative surgery were retrospectively enrolled to the present study. GLUT1 and PKM2 expression was assessed using immunohistochemistry. Subsequently, the association between the clinicopathological features of patients with NSCLC and the expression of GLUT1 and PKM2 was assessed. Of the 445 patients with NSCLC included in the present study, 65 (15%) were positive for both GLUT1 and PKM2 expression (G+/P+ group). GLUT1 and PKM2 positivity was significantly associated with sex, absence of adenocarcinoma, lymphatic invasion and pleural invasion. Furthermore, patients with NSCLC in the G+/P+ group presented significantly poorer survival rates than those expressing other markers. G+/P+ expression was significantly associated with poor disease-free survival. In conclusion, the findings of the present study indicated that the combination of GLUT1 and PKM2 may be considered a reliable prognostic factor for patients with NSCLC following curative resection, especially in patients with stage I NSCLC.

Predicting response to neoadjuvant therapy with glucose transporter-1 in breast cancer

OBJECTIVE

Glucose transporter-1 is a marker involved in energy transport in cancer cells. It has been shown to be a poor prognostic factor in many cancer types, including breast cancer. However, there is no satisfactory parameter predicting treatment in breast cancer patients receiving neoadjuvant therapy. This study investigated the effect of glucose transporter-1 in predicting the treatment response of patients receiving neoadjuvant therapy.

METHODS

In this study, glucose transporter-1 immunohistochemistry was applied to tru-cut biopsy of patients who were diagnosed with breast cancer and received neoadjuvant therapy between 2010 and 2021. A built-in scoring system was used to evaluate both the pattern and intensity of glucose transporter-1 immunohistochemistry staining. The relationship between glucose transporter-1 immunohistochemistry staining and other clinicopathological parameters was examined. In addition, the relationship of glucose transporter-1 with response to treatment was investigated.

RESULTS

A relationship was found between high glucose transporter-1 expression and other clinicopathological parameters (such as estrogen and progesterone receptor negativity, high Ki-67, triple-negative, and Her2 status). Cases with high glucose transporter-1 expression had either a complete or a partial pathologic response. The result was statistically significant.

CONCLUSION

Glucose transporter-1 has the potential to be a biomarker that can be evaluated more objectively as an alternative to Ki-67 labeling index in evaluating the response to treatment in patients receiving neoadjuvant therapy.

SLC2As as diagnostic markers and therapeutic targets in LUAD patients through bioinformatic analysis

Facilitative glucose transporters (GLUTs), which are encoded by solute carrier 2A (SLC2A) genes, are responsible for mediating glucose absorption. In order to meet their higher energy demands, cancer cells are more likely than normal tissue cells to have elevated glucose transporters. Multiple pathogenic processes, such as cancer and immunological disorders, have been linked to GLUTs. Few studies, meanwhile, have been conducted on individuals with lung adenocarcinoma (LUAD) to evaluate all 14 SLC2A genes. We first identified increased protein levels of SLC2A1, SLC2A5, SLC2A6, and SLC2A9 via HPA database and downregulated mRNA levels of SLC2A3, SLC2A6, SLC2A9, and SLC2A14 by ONCOMINE and UALCAN databases in patients with LUAD. Additionally, lower levels of SLC2A3, SLC2A6, SLC2A9, SLC2A12, and SLC2A14 and higher levels of SLC2A1, SLC2A5, SLC2A10, and SLC2A11 had an association with advanced tumor stage. SLC2A1, SLC2A7, and SLC2A11 were identified as prognostic signatures for LUAD. Kaplan-Meier analysis, Univariate Cox regression, multivariate Cox regression and ROC analyses further revealed that these three genes signature was a novel and important prognostic factor. Mechanistically, the aberrant expression of these molecules was caused, in part, by the hypomethylation of SLC2A3, SLC2A10, and SLC2A14 and by the hypermethylation of SLC2A1, SLC2A2, SLC2A5, SLC2A6, SLC2A7, and SLC2A11. Additionally, SLC2A3, SLC2A5, SLC2A6, SLC2A9, and SLC2A14 contributed to LUAD by positively modulating M2 macrophage and T cell exhaustion. Finally, pathways involving SLC2A1/BUB1B/mitotic cell cycle, SLC2A5/CD86/negative regulation of immune system process, SLC2A6/PLEK/lymphocyte activation, SLC2A9/CD4/regulation of cytokine production might participate in the pathogenesis of LUAD. In summary, our results will provide the theoretical basis on SLC2As as diagnostic markers and therapeutic targets in LUAD.

Role of psoriatic keratinocytes in the metabolic reprogramming of dermal mesenchymal stem cells

BACKGROUND

Psoriasis is an immune-mediated inflammatory skin disease, featured by epidermal hyperproliferation. Psoriasis exhibits metabolic abnormalities, which can further aggravate the condition of psoriasis. The present study aimed to investigate the role of psoriatic keratinocytes (KCs) in the metabolic reprogramming of dermal mesenchymal stem cells (DMSCs).

METHODS

Dermal mesenchymal stem cells were cocultured with primary KCs either from psoriatic lesions or from normal subjects using Transwell plate. Glycolysis and mitochondrial metabolism of DMSCs were detected by Seahorse Metabolic Analyzer. Expression levels of proteins were analyzed by Western blotting. DMSCs proliferation was assessed using 5-ethynyl-2'-deoxyuridine assay and Cell Counting Kit-8.

RESULTS

In comparison with normal KCs, coculture of psoriatic KCs with DMSCs dramatically increased glycolytic and mitochondrial metabolism, and expression levels of stem cell factor, epidermal growth factor, glucose transporter 1, and c-Myc. Moreover, psoriatic KCs were more potent than normal KCs in the stimulation of DMSC proliferation.

CONCLUSIONS

In conclusion, psoriatic KCs display a higher potency in metabolic reprogramming and stimulation of DMSC proliferation, possibly contributing to the pathogenesis of psoriasis. However, whether the intervention of metabolic reprogramming of DMSCs can alleviate psoriasis remains to be determined.

The Effect of GLUT1 on Survival Rate and the Immune Cell Infiltration of Lung Adenocarcinoma and Squamous Cell Carcinoma: A Meta and Bioinformatics Analysis

BACKGROUND

Lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC) are two major subtypes of non-small cell lung cancer (NSCLC). Studies have shown that abnormal expression of glucose transport type 1 (GLUT1) in NSCLC patients has been associated with progression, aggressiveness, and poor clinical outcome. However, the clinical effect of GLUT1 expression on LUAD and LUSC is unclear.

OBJECTIVE

This study aims to learn more about the character of GLUT1 in LUAD and LUSC.

METHODS

A meta-analysis was performed to evaluate the GLUT1 protein level, and bioinformatics analysis was used to detect the GLUT1 mRNA expression level, survival differences, and the infiltration abundance of immune cells in samples from TCGA. Meanwhile, functional and network analysis was conducted to detect important signaling pathways and key genes with the Gene Expression Omnibus (GEO) dataset.

RESULTS

Our results showed that GLUT1 was over-expressed both in LUAD and LUSC. LUAD patients with high GLUT1 expression had a poor prognosis. Additionally, GLUT1 was related to B cell and neutrophil infiltration of LUAD. In LUSC, GLUT1 was correlated with tumor purity, B cell, CD8⁺ T cell, CD4⁺ T cell, macrophage, neutrophil, and dendritic cell infiltration. The GEO dataset analysis results suggested GLUT1 potentially participated in the p53 signaling pathway and metabolism of xenobiotics by cytochrome P450 and was associated with KDR, TOX3, AGR2, FOXA1, ERBB3, ANGPT1, and COL4A3 gene in LUAD and LUSC.

CONCLUSION

GLUT1 might be a potential biomarker for aggressive progression and poor prognosis in LUAD, and a therapeutic biomarker in LUSC.

Assessment of relationships among clinicopathological characteristics, morphological computer tomography features, and tumor cell proliferation in stage I lung adenocarcinoma

Background

Surgically resected stage I lung adenocarcinoma (ADC) has wide variation in prognosis. It is significant to identify high-risk patients and optimize therapeutic strategy. This study aimed to investigate the relationships among histological grade, serum tumor marker index (TMI), morphological computer tomography (CT) features, and a well-established prognosticator cell proliferation (Ki-67) in stage I ADC.

Methods

Preoperative CT was performed in 182 patients with stage I ADC confirmed by pathology. The Ki-67 expression was acquired by immunohistochemistry. TMI was the square root of standardized serum carcinoembryonic antigen (CEA) and cytokeratin 19 fragments (CYFRA 21-1) values. Tumor shadow disappearance rate (TDR) and other morphological CT features were interpreted by two radiologists. Histological grade, TMI, CT features were statistically evaluated to explore the associations with Ki-67 expression.

Results

In univariate analysis, gender, smoking history, pack-year, histological grade, TNM stage (IA and IB), serum CEA and CYFRA 21-1 status, TMI status, as well as TDR, long-axis diameter, short-axis diameter, lobulation, spiculation, attenuation types, vacuolation, vascular invasion, vascular convergence, thickened bronchovascular bundles, pleural attachment and peripheral fibrosis were significantly associated with Ki-67 expression (all P<0.05). Solid-predominant ADC had the highest Ki-67 expression, followed by micropapillary, papillary and acinar-predominant ADC, while lepidic-predominant ADC had the lowest Ki-67 expression (P<0.001). TDR was negatively correlated with Ki-67 (r =−0.478, P<0.001). Multivariate logistic regression analysis revealed that gender, histological grade, TDR and attenuation types were independent factors associated with Ki-67 expression.

Conclusions

Ki-67 expression differed distinctly according to ADC histological subtypes. High Ki-67 expression is independently associated with male patients of stage I ADC with worse differentiation, lower TDR and solid tumors, which might be of prognostic value for poor prognosis in stage I ADC.

Anti-tumor efficacy of CKD-516 in combination with radiation in xenograft mouse model of lung squamous cell carcinoma

BACKGROUND

Hypoxic tumors are known to be highly resistant to radiotherapy and cause poor prognosis in non-small cell lung cancer (NSCLC) patients. CKD-516, a novel vascular disrupting agent (VDA), mainly affects blood vessels in the central area of the tumor and blocks tubulin polymerization, thereby destroying the aberrant tumor vasculature with a rapid decrease in blood, resulting in rapid tumor cell death. Therefore, we evaluated the anti-tumor efficacy of CKD-516 in combination with irradiation (IR) and examined tumor necrosis, delayed tumor growth, and expression of proteins involved in hypoxia and angiogenesis in this study.

METHODS

A xenograft mouse model of lung squamous cell carcinoma was established, and the tumor was exposed to IR 5 days per week. CKD-516 was administered with two treatment schedules (day 1 or days 1 and 5) 1 h after IR. After treatment, tumor tissues were stained with hematoxylin and eosin, and pimonidazole. HIF-1α, Glut-1, VEGF, CD31, and Ki-67 expression levels were evaluated using immunohistochemical staining.

RESULTS

Short-term treatment with IR alone and CKD-516 + IR (d1) significantly reduced tumor volume (p = 0.006 and p = 0.048, respectively). Treatment with CKD-516 + IR (d1 and d1, 5) resulted in a marked reduction in the number of blood vessels (p < 0.005). More specifically, CKD-516 + IR (d1) caused the most extensive tumor necrosis, which resulted in a significantly large hypoxic area (p = 0.02) and decreased HIF-1α, Glut-1, VEGF, and Ki-67 expression. Long-term administration of CKD-516 + IR reduced tumor volume and delayed tumor growth. This combination also greatly reduced the number of blood vessels (p = 0.0006) and significantly enhanced tumor necrosis (p = 0.004). CKD-516 + IR significantly increased HIF-1α expression (p = 0.0047), but significantly reduced VEGF expression (p = 0.0046).

CONCLUSIONS

Taken together, our data show that when used in combination, CKD-516 and IR can significantly enhance anti-tumor efficacy compared to monotherapy in lung cancer xenograft mice.

Screening of Hub Gene Targets for Lung Cancer via Microarray Data

BACKGROUND

Lung cancer is one of the malignancies exhibiting the fastest increase in morbidity and mortality, but the cause is not clearly understood. The goal of this investigation was to screen and identify relevant biomarkers of lung cancer.

METHODS

Publicly available lung cancer data sets, including GSE40275 and GSE134381, were obtained from the GEO database. The repeatability test for data was done by principal component analysis (PCA), and a GEO2R was performed to screen differentially expressed genes (DEGs), which were all subjected to enrichment analysis. Protein-protein interactions (PPIs), and the significant module and hub genes were identified via Cytoscape. Expression and correlation analysis of hub genes was done, and an overall survival analysis of lung cancer was performed. A receiver operating characteristic (ROC) curve analysis was performed to test the sensitivity and specificity of the identified hub genes for diagnosing lung cancer.

RESULTS

The repeatability of the two datasets was good and 115 DEGs and 10 hub genes were identified. Functional analysis revealed that these DEGs were associated with cell adhesion, the extracellular matrix, and calcium ion binding. The DEGs were mainly involved with ECM-receptor interaction, ABC transporters, cell-adhesion molecules, and the p53 signaling pathway. Ten genes including COL1A2, POSTN, DSG2, CDKN2A, COL1A1, KRT19, SLC2A1, SERPINB5, DSC3, and SPP1 were identified as hub genes through module analysis in the PPI network. Lung cancer patients with high expression of COL1A2, POSTN, DSG2, CDKN2A, COL1A1, SLC2A1, SERPINB5, and SPP1 had poorer overall survival times than those with low expression (p <0.05). The CTD database showed that 10 hub genes were closely related to lung cancer. Expression of POSTN, DSG2, CDKN2A, COL1A1, SLC2A1, SERPINB5, and SPP1 was also associated with a diagnosis of lung cancer (p<0.05). ROC analysis showed that SPP1 (AUC = 0.940, p = 0.000*, 95%CI = 0.930-0.973, ODT = 7.004), SLC2A1 (AUC = 0.889, p = 0.000*, 95%CI = 0.791-0.865, ODT = 7.123), CDKN2A (AUC = 0.730, p = 0.000*, 95%CI = 0.465-1.000, ODT = 6.071) were suitable biomarkers.

CONCLUSION

Microarray technology represents an effective method for exploring genetic targets and molecular mechanisms of lung cancer. In addition, the identification of hub genes of lung cancer provides novel research insights for the diagnosis and treatment of lung cancer.

Heterogeneity of Glucose Transport in Lung Cancer

Increased glucose uptake is a known hallmark of cancer. Cancer cells need glucose for energy production via glycolysis and the tricarboxylic acid cycle, and also to fuel the pentose phosphate pathway, the serine biosynthetic pathway, lipogenesis, and the hexosamine pathway. For this reason, glucose transport inhibition is an emerging new treatment for different malignancies, including lung cancer. However, studies both in animal models and in humans have shown high levels of heterogeneity in the utilization of glucose and other metabolites in cancer, unveiling a complexity that is difficult to target therapeutically. Here, we present an overview of different levels of heterogeneity in glucose uptake and utilization in lung cancer, with diagnostic and therapeutic implications.

The impact of epidermal growth factor receptor mutations on the prognosis of resected non-small cell lung cancer: a meta-analysis of literatures

BACKGROUND

Epidermal growth factor receptor (EGFR) mutation represents a good response to EGFR-tyrosine kinase inhibitor and an advantageous prognostic factor in advanced-stage non-small cell lung cancer (NSCLC). However, the predictive value of EGFR mutation for prognosis in NSCLC patients after complete surgery, which more reflective of natural process, remains controversial. We sought to examine the predictive value of EGFR mutation in NSCLC. Several studies with small sample sizes have been reported but small studies bring bias especially in a postoperative setting. Therefore, we sought to pool all current evidence to show the true effects.

METHODS

Electronic databases were used to search the relevant articles. Disease-free survival (DFS), which will be less effected by subsequent treatments after recurrence, was the primary endpoint. The DFS between EGFR mutated and wild-type patients were compared focus on stage I patients who are rarely received adjuvant therapy. Besides, the DFS of patients with 19 exon deletion (19del) and 21 exon L858R mutation (L858R) were compared. A random effects model was used.

RESULTS

A total of 19 relevant studies which involved 4,872 cases were enrolled and 2,086 patients were EGFR-mutated. The majority of studies used PCR-based methods to detect EGFR mutations. Through meta-analysis, we observed the DFS of EGFR-mutated patients were similar to wild type patients in overall population (HR 0.93, 95% CI: 0.74 to 1.17). Similar results were observed in stage I subgroup (HR 0.82, 95% CI: 0.50 to 1.33). DFS of 19 del patients were potentially inferior to L858R patients but the difference was not significant (HR 1.38, 95% CI: 0.76 to 2.52).

CONCLUSIONS

There was no significant difference in postoperative DFS between EGFR-mutant patients and wild-type with resected NSCLC. In addition, there is still insufficient evidence to support different postoperative treatment strategies (especially for stage I) for both mutated and wild-type patients. However, 19 del may be a negative factor, which may require more strict management. Thus, we strongly encourage reporting specific prognostic impacts of different mutation types.

Prognostic value of Ki-67 in stage I non-small-cell lung cancer: A meta-analysis involving 1931 patients

There is growing interest in exploring the prognostic value of Ki-67 in non-small-cell lung cancer (NSCLC). However, whether Ki-67 can be regarded as a routine biomarker in clinical practice is still under debate. The present meta-analysis investigated the relationship between Ki-67 and the overall survival (OS) or disease-free survival (DFS) of patients suffering from stage I NSCLC. We searched the Web of Science, Cochrane, and PubMed databases to extract eligible articles. In total, 15 studies involving 1931 patients were included. Pooled hazard ratio (HR) analysis revealed that patients with high Ki-67 labeling index (LI) had poorer OS (HR = 1.95, 95% confidence interval (CI) = 1.43-2.66, P < 0.0001) and DFS (HR = 3.12, 95% CI = 2.17-4.48, P < 0.00001) than those with low Ki-67 LI. In subgroup analysis, high Ki-67 LI was significantly associated with poor prognoses in stage I adenocarcinoma. In future studies, a consensus for the optimal cutoff value for high Ki-67 LI needs to be explored and demonstrated in stage I NSCLC patients.

Macrophage Origin, Metabolic Reprogramming and IL-1 Signaling: Promises and Pitfalls in Lung Cancer

Macrophages are tissue-resident cells that act as immune sentinels to maintain tissue integrity, preserve self-tolerance and protect against invading pathogens. Lung macrophages within the distal airways face around 8000⁻9000 L of air every day and for that reason are continuously exposed to a variety of inhaled particles, allergens or airborne microbes. Chronic exposure to irritant particles can prime macrophages to mediate a smoldering inflammatory response creating a mutagenic environment and favoring cancer initiation. Tumor-associated macrophages (TAMs) represent the majority of the tumor stroma and maintain intricate interactions with malignant cells within the tumor microenvironment (TME) largely influencing the outcome of cancer growth and metastasis. A number of macrophage-centered approaches have been investigated as potential cancer therapy and include strategies to limit their infiltration or exploit their antitumor effector functions. Recently, strategies aimed at targeting IL-1 signaling pathway using a blocking antibody have unexpectedly shown great promise on incident lung cancer. Here, we review the current understanding of the bridge between TAM metabolism, IL-1 signaling, and effector functions in lung adenocarcinoma and address the challenges to successfully incorporating these pathways into current anticancer regimens.

PD-L1 protein expression in non-small-cell lung cancer and its relationship with the hypoxia-related signaling pathways: A study based on immunohistochemistry and RNA sequencing data

OBJECTIVES

Therapies that target programmed cell death protein-1 (PD-1)/programmed death-ligand 1 (PD-L1) have shown promising efficacy in non-small-cell lung cancer (NSCLC). Hypoxia-related genes are also important regulators of PD-L1, and the role of PD-L1 in NSCLC is still not clear. The objective of this study was to investigate PD-L1 expression and its correlation with hypoxic-inducible factor 1α (HIF1A), vascular endothelial growth factor A (VEGFA), glucose transporter 1 (GLUT1), and carbonic anhydrase 9 (CAIX) expression in NSCLC patients. The association between PD-L1 expression and survival was also determined.

MATERIALS AND METHODS

PD-L1/protein expression was evaluated in 295 resected NSCLCs and its correlation with HIF1A, VEGFA, GLUT1, CAIX expression and survival was determined based on immunohistochemical and RNA sequencing data obtained from The Cancer Genome Atlas (TCGA) database.

RESULTS

PD-L1 protein expression was significantly correlated with HIF1A, VEGFA, GLUT1, and CAIX expression only in adenocarcinoma when a 10% or a 50% cut-off was used. PD-L1 mRNA expression was also significantly correlated with HIF1A, VEGFA, GLUT1, and CAIX expression in adenocarcinoma. Univariate analysis revealed that HIF1A expression was associated with poor recurrence-free survival (RFS), and GLUT1 was associated with poor overall survival (OS) and RFS. GLUT1 was an independent prognostic factor for OS in multivariate analysis of immunohistochemical and TCGA data (p = 0.024 and 0.029, respectively). Patients with low expression of both PD-L1 and GLUT1 had longer OS than other patterns in immunohistochemical and TCGA data (p = 0.003 and 0.051, respectively).

CONCLUSIONS

PD-L1 protein and mRNA expression were correlated with HIF1A, VEGFA, GLUT1, and CAIX expression in adenocarcinoma alone. Low expression of GLUT1 and low expression of both PD-L1 and GLUT1 were associated with improved prognosis. Our findings support the rationale for co-targeting hypoxia-related genes and PD-L1 in cancer therapy. Expression of hypoxia-related genes may be helpful in selecting patients appropriate for PD-L1 therapy.

Glucose transporter 1 in health and disease

Glucose, a major source of energy for all cells, is transported into cells with the help of glucose transporters (GLUTs). These transporters are of two types, namely sodium-dependent GLUTs and facilitative GLUTs. These transporters are present in a tissue-specific pattern and have substrate specificity. Among these transporters, GLUT1 (facilitative GLUT) is present ubiquitously on all tissues of the body and helps in the basal uptake of glucose. GLUT1 is known to have many physiological functions in the body from the time of implantation of an embryo and is also seen associated with pathologies, including cancers. This review mainly focuses on GLUT1 in physiological and pathological conditions and the recent advances related to its role in cancer development and applications in cancer therapeutics.

The clinicopathologic impacts and prognostic significance of GLUT1 expression in patients with lung cancer: A meta-analysis

BACKGROUND

Accumulating studies have reported that GLUT1 is aberrantly expressed in lung cancer; nevertheless, the clinicopathologic significance and the prognostic role of GLUT1 still remain controversial. The aim of this meta-analysis was to identify the clinicopathologic and prognostic implications of the GLUT1 expression in lung cancer patients.

MATERIALS AND METHODS

Databases with literature published in English, including Cochrane Library, Embase, Web of Science, and PubMed, and the China National Knowledge Infrastructure (CNKI) and WanFang database in Chinese were searched comprehensively for relevant studies in August 2017. The pooled odds ratio (OR) or hazard ratio (HR) with 95% confidence intervals (CIs) were calculated to evaluate the clinicopathologic significance and prognostic value of GLUT1 in lung cancer.

RESULTS

A total of 26 studies (2653 cases) were included in the current study. Totally, 1423 patients from nineteen studies were included to assess the relationships between GLUT1 and clinicopathological parameters, the pooled OR indicated that positive GLUT1 expression was significantly related with classification (adenocarcinomas vs. squamous carcinomas, OR = 0.276, 95% CIs: 0.117-0.651, P = 0.003), tumor differentiation (G3-4 vs. G2~1, OR = 1.944, 95% CIs: 1.384-2.730; P < 0.001), lymph node metastasis (positive vs. negative, OR = 3.65, 95% CIs: 1.82-7.32, P < 0.001),tumor size (large tumor size vs. small tumor size, OR = 2.03, 95% CI: 1.42-2.91, P < 0.001), and advanced tumor stages (OR = 2.527, 95% CIs: 1.325-4.820). Regarding the significance of GLUT1 in the overall survival (OS) of lung cancer, the pooled HRs with 1731 lung cancer patients was 1.41 (P = 0.002; 95% CIs: 1.13-1.76). Additionally, the overexpression of GLUT1 could significantly predict the shorter disease-free survival (HR = 1.68, 95% CIs: 1.01-2.79) and disease-specific survival (HR = 1.59, 95% CIs: 1.11-2.29).

CONCLUSIONS

A positive expression of GLUT1 significantly predicts a poor prognosis in lung cancer patients. GLUT1 may server as a helpful biomarker and a potential target for the treatment strategies of lung cancer.

Prognostic value of EGFR and KRAS in resected non-small cell lung cancer: a systematic review and meta-analysis

Background

The prognostic value of EGFR and KRAS mutations in resected non-small cell lung cancer (NSCLC) has been reported. However, conflicting results were reported in these studies. The effect of mutations in these two genes in resected NSCLC remains controversial.

Methods

We searched Internet databases for studies reporting disease-free survival (DFS) and overall survival (OS) in resected NSCLC patients with EGFR or KRAS mutations. A meta-analysis calculating the pooled hazard ratio (HR) for DFS and OS was used to measure the association of EGFR or KRAS mutations with the prognosis of patients after surgery.

Results

A total of 9,635 patients from 32 studies were included in this analysis. The combined HR for EGFR mutations on DFS was 0.77 (95% CI 0.66–0.90, p=0.001) and on OS was 0.72 (95% CI 0.66–0.80, p<0.00001). In addition, the combined HR for KRAS mutations on DFS was 1.5 (95% CI 1.15–1.96, p=0.002) and on OS was 1.49 (95% CI 1.28–1.73, p<0.00001). Sensitivity analysis, subgroup analysis, and bias analysis proved the stability of the results.

Conclusion

The analysis showed that EGFR mutations were significantly associated with DFS and OS. These findings indicated that surgically treated NSCLC patients with EGFR mutations were inclined to exhibit a prolonged DFS and OS. In addition, the results indicated that KRAS mutations predicted worse DFS and OS in patients with resected NSCLC.

Augmented expression of Ki-67 is correlated with clinicopathological characteristics and prognosis for lung cancer patients: an up-dated systematic review and meta-analysis with 108 studies and 14,732 patients

Background

Lung cancer ranks as the leading cause of cancer-related deaths worldwide and we performed this meta-analysis to investigate eligible studies and determine the prognostic effect of Ki-67.

Methods

In total, 108 studies in 95 articles with 14,732 patients were found to be eligible, of which 96 studies reported on overall survival (OS) and 19 studies reported on disease-free survival (DFS) with relation to Ki-67 expression in lung cancer patients.

Results

The pooled hazard ratio (HR) indicated that a high Ki-67 level could be a valuable prognostic factor for lung cancer (HR = 1.122 for OS, P < 0.001 and HR = 1.894 for DFS, P < 0.001). Subsequently, the results revealed that a high Ki-67 level was significantly associated with clinical parameters of lung cancer including age (odd ratio, OR = 1.246 for older patients, P = 0.018), gender (OR = 1.874 for males, P < 0.001) and smoking status (OR = 3.087 for smokers, P < 0.001). Additionally, significant positive correlations were found between Ki-67 overexpression and poorer differentiation (OR = 1.993, P = 0.003), larger tumor size (OR = 1.436, P = 0.003), and higher pathologic stages (OR = 1.867 for III-IV, P < 0.001). Furthermore, high expression of Ki-67 was found to be a valuable predictive factor for lymph node metastasis positive (OR = 1.653, P < 0.001) and advanced TNM stages (OR = 1.497 for stage III-IV, P = 0.024). Finally, no publication bias was detected in any of the analyses.

Conclusions

This study highlights that the high expression of Ki-67 is clinically relevant in terms of the prognostic and clinicopathological characteristics for lung cancer. Nevertheless, more prospective well-designed studies are warranted to validate these findings.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0843-7) contains supplementary material, which is available to authorized users.

High USP6NL Levels in Breast Cancer Sustain Chronic AKT Phosphorylation and GLUT1 Stability Fueling Aerobic Glycolysis

USP6NL, also named RN-tre, is a GTPase-activating protein involved in control of endocytosis and signal transduction. Here we report that USP6NL is overexpressed in breast cancer, mainly of the basal-like/integrative cluster 10 subtype. Increased USP6NL levels were accompanied by gene amplification and were associated with worse prognosis in the METABRIC dataset, retaining prognostic value in multivariable analysis. High levels of USP6NL in breast cancer cells delayed endocytosis and degradation of the EGFR, causing chronic AKT (protein kinase B) activation. In turn, AKT stabilized the glucose transporter GLUT1 at the plasma membrane, increasing aerobic glycolysis. In agreement, elevated USP6NL sensitized breast cancer cells to glucose deprivation, indicating that their glycolytic capacity relies on this protein. Depletion of USP6NL accelerated EGFR/AKT downregulation and GLUT1 degradation, impairing cell proliferation exclusively in breast cancer cells that harbored increased levels of USP6NL. Overall, these findings argue that USP6NL overexpression generates a metabolic rewiring that is essential to foster the glycolytic demand of breast cancer cells and promote their proliferation.Significance: USP6NL overexpression leads to glycolysis addiction of breast cancer cells and presents a point of metabolic vulnerability for therapeutic targeting in a subset of aggressive basal-like breast tumors.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/13/3432/F1.large.jpg Cancer Res; 78(13); 3432-44. ©2018 AACR.

The prognostic value of GLUT1 in cancers: a systematic review and meta-analysis

Increased glycolysis is one of the hallmarks of cancer. The abnormal expression of glucose transporter 1 (GLUT1) was reported to be associated with resistance to current therapy and poor prognosis. Numerous studies have investigated the correlation between GLUT1 expression and prognosis in cancers, but the conclusions are still controversial. Here, we conducted a meta-analysis to explore the association between GLUT1 and survival in human cancers. PubMed, Springer, Medline, and Cochrane Library were searched carefully to identify eligible studies evaluating prognostic value of GLUT1 in cancers. Twenty-seven studies with 4079 patients were included in the present study. Our pooled results identified that increased expression of GLUT1 was associated with unfavorable overall survival (HR = 1.780, 95% CI = 1.574–.013, p < 0.001)) and poorer disease-free survival (HR = 1.95, 95% CI = 1.229–3.095, p = 0.003). Furthermore, overexpression of GLUT1 linked with poor differentiated tumors (RR = 1.380, 95% CI = 1.086–1.755, p = 0.009; I² = 72.0%, p < 0.001), positive lymph node metastasis (RR = 1.395, 95% CI = 1.082–1.799, p = 0.010; I² = 70.8%, p = 0.002) and larger tumor size (RR = 1.405, 95% CI = 1.231–1.603, p < 0.001; I² = 37.3%, p = 0.093). This systematic review and meta-analysis indicated that the GLUT1 may serve as an ideal prognostic biomarker in various cancers.

GLUT-1 overexpression as an unfavorable prognostic biomarker in patients with colorectal cancer

Background

Glucose transporter-1 (GLUT-1) exhibits altered expression in colorectal cancer (CRC). The aim of this study was to explore the association between GLUT-1 and survival conditions, as well as clinical features in CRC by meta-analysis.

Materials and Methods

Relevant studies were searched through predefined strategies, hazard ratios (HRs), odds ratios (ORs), and their 95% confidence intervals (CIs) were used as effective measures.

Results

A total of 14 studies with 2,077 patients were included in this meta-analysis. The results showed that GLUT-1 was not significantly associated with overall survival (OS) (HR=1.28, 95% CI=0.86–1.91, p=0.22) or disease-free survival (DFS) (HR=1.71, 95% CI=0.78–3.72, p=0.179). However, subgroup analysis indicated that GLUT-1 was a significant biomarker for poor DFS in rectal cancer (HR=2.47, 95% CI=1.21–5.05, p=0.013). GLUT-1 expression was also found to be significantly correlated with the presence of lymph node metastasis (n=8, OR=2.14, 95% CI=1.66–2.75, p<0.001), T stage (n=6, OR=1.73, 95% CI=1.17–2.58, p=0.007), higher Dukes stage (n=5, OR=2.92, 95% CI=2.16–3.95, p<0.001), female sex (n=4, OR=2.92, 95% CI=2.16–3.95, p<0.001), and presence of liver metastasis (n=3, OR=1.82, 95% CI=1.06–3.12, p=0.03).

Conclusion

In conclusion, this meta-analysis showed that GLUT-1 was associated with poor DFS in rectal cancer (RC). Furthermore, GLUT-1 was also an indicator of aggressive clinical features in CRC.

Prognostic value of GLUT-1 expression in pancreatic cancer: results from 538 patients

Objective

Previous studies have suggested a correlation between glucose transporter-1 (GLUT-1) expression and survival outcomes in pancreatic cancer, although the results were inconsistent. We subsequently carried out a meta-analysis, with the aim of comprehensively reevaluating the associations between GLUT-1 expression and overall survival (OS) and other clinical features of pancreatic cancer.

Results

Eight studies, with a total of 538 cases, were included in the final meta-analysis. The HR and 95% CI for OS were 1.79 and 1.19-2.7, respectively (p=0.005). GLUT-1 overexpression was associated with tumor size (>2 cm vs. ≤2 cm; OR=2.16, 95% CI=1.2-3.9, p=0.01) and lymph node metastasis (yes vs. no; OR=3.29, 95% CI=1.38-7.84, p=0.007). However, there was no significant association between GLUT-1 expression and histological grade, age, sex, TNM stage, or vascular invasion status. There was no evidence of significant publication bias in this meta-analysis.

Materials and Methods

Relevant databases were searched using predefined searching items until September 2016. The pooled hazard ratios (HR) with 95% confidence interval (CI) for OS and the pooled odds ratio (OR) with 95% CI for clinical factors were calculated.

Conclusions

High GLUT-1 expression predicted shorter OS in patients with pancreatic cancer. Moreover, GLUT-1 expression was associated with a tumor size of >2 cm and presence of lymph node metastasis.

Expression of glucose transporter 1 and prognosis in non-small cell lung cancer: a pooled analysis of 1665 patients

Glucose transporter 1 (GLUT1) plays an important role in the transport and metabolism of glucose in cancer cells. An increasing number of studies have explored the connection between GLUT1 expression and prognosis in non-small cell lung cancer (NSCLC), but the results have been controversial. Therefore, we conducted a meta-analysis to obtain a comprehensive evaluation of the prognostic value of GLUT1 in NSCLC. Relevant studies from PubMed, Embase, and Web of Science were searched. Hazard ratios (HRs) and odds ratios (ORs) with their 95% confidence intervals (CIs) were used as the effective measures. A total of 10 studies involving 1,665 patients were included in this meta-analysis. The results showed that GLUT1 overexpression was associated with poor overall survival (HR = 2.21; 95% CI, 1.42-3.42; p < 0.001) and disease-free survival (HR = 1.73; 95% CI, 1.35-2.23; p < 0.001). Furthermore, elevated GLUT1 expression correlated with sex (OR = 2.29; 95% CI, 1.17-4.49; p = 0.015), advanced tumor stage (OR = 2.46; 95% CI, 1.79-3.38; p < 0.001), histology (OR = 6.99; 95% CI, 4.71-10.38; p < 0.001), and large tumor size (OR = 2.77; 95% CI, 1.73-4.44; p < 0.001). This meta-analysis revealed overexpression of GLUT1 to be a biomarker of worse prognosis in NSCLC.

Sex-related differences of urethane and sodium valproate effects on Ki-67 expression in urethane-induced lung tumors of mice

The aim of the present study was to evaluate sex differences in tumorigenesis by assessing the number of Ki-67-positive cells [Ki-67(+)] in urethane-induced mice lung tumors and the effect of sodium valproate (NaVP) in BALB/c mice. Gonad-intact and gonadectomized female and male mice were divided into the following groups: i) Treated with urethane, ii) treated with urethane and NaVP and iii) gonad-intact or gonadectomized control. Urethane (total 50 mg/mouse) was injected intraperitoneally. The NaVP 0.4% solution was administered orally for 6 months. Histologically, lung tumors were divided into adenomas and adenocarcinomas and assessed immunohistochemically using antibodies against Ki-67. The Ki-67(+) was calculated per one mm² of a tumor. In adenomas, Ki-67(+) in the urethane-treated gonad-intact males was significantly higher than in females (P=0.001) and in castrated males (P<0.01); Ki-67(+) in adenomas of the urethane-treated gonad-intact males was significantly higher than in urethane-NaVP-treated ones (P<0.04). No significant differences were found in analogous female groups. In adenocarcinomas, Ki-67(+) in urethane-treated gonad-intact males was significantly higher than in females and gonadectomized mice of both sexes (P<0.001), and in ovariectomized females was significantly higher than in ovary-intact group (P=0.01). A significantly higher number of Ki-67(+) cells were observed in gonad-intact adenocarcinomas of the urethane-NaVP-treated females compared with the urethane-treated ones (P<0.001). Comparing between urethane-NaVP-treated gonadectomized males and females in adenocarcinomas, determined that Ki-67(+) was significantly lower in females (P=0.005). In adenocarcinomas, Ki-67(+) in urethane-NaVP-treated gonadectomized males and females was significantly lower than in gonad-intact mice of the same sex (P<0.001). In summary, gonadectomy with NaVP treatment decreased Ki-67(+) in adenocarcinomas for mice of both sexes. The results of the present study indicate sex-related differences in mice lung tumorigenesis, and a sex-related effect of NaVP on progression in urethane-induced BALB/c mice lung tumors.

Validity and clinical impact of glucose transporter 1 expression in colorectal cancer

BACKGROUND/AIM

There is no doubt that colorectal cancer (CRC) poses a major threat to public health worldwide, and despite improvement in managements, prognosis still remains an irritating question with no definite answer. Being a fundamental player in cancer metabolism, glucose transporter 1 (GLUT1) could be utilized as a prognostic biomarker that could fuel development of new treatment strategies. The aim of this study was to assess the validity of GLUT1 expression as a prognostic biomarker and to elucidate to what extent it is immersed in poor clinical outcome among CRC patients.

PATIENTS AND METHODS

GLUT1 expression in peripheral blood specimens was analyzed by quantitative real-time polymerase chain reaction in 47 CRC patients and 20 healthy controls.

RESULTS

There was significantly elevated GLUT1 expression in peripheral blood of CRC patients than in controls (P < 0.001). The cutoff value of 0.605 provided 98% sensitivity and 100% specificity. There were significantly higher values of GLUT1 expression in patients under 50 years (P = 0.003), performance status 2 (P = 0.009), stage IV (P < 0.001), and presence of metastasis (P < 0.001). GLUT1 expression showed nonsignificant association with overall survival (P = 0.068), while tumor stage (P = 0.01) and metastasis (P = 0.009) were significantly associated with lower overall survival.

CONCLUSION

GLUT1 is sensitive and specific marker for CRC. It is overexpressed in young age patients, poor performance status, and stage IV patients. Although this was not statistically significant, GLUT 1 showed higher expression level in patients with lesser survival.

Diagnostic roles of MUC1 and GLUT1 in differentiating thymic carcinoma from type B3 thymoma

MUC1 is a transmembrane mucin that has been related to tumor progression and outcome in various malignancies. GLUT1 is a member of the mammalian facilitative glucose transporter (GLUT) family of passive carriers that functions as an energy-independent system for transporting glucose. Both of them are useful markers for the diagnosis, progression, and prognosis of various tumors, especially those that are cancerous. However, the clinical significance of MUC1 and GLUT1 in thymic epithelial tumors remains uncertain due to a lack of quality specimen and studies at sufficient scale, both owing, in part, to the rarity of the tumors. The aim of this article is to study the expression patterns of MUC1 and GLUT1 in thymic carcinoma and type B3 thymoma, and to evaluate their diagnostic value for these two types of tumors via immunohistochemistry. Forty-three patients were included in the study, including twenty-two with thymic carcinoma and twenty-one with type B3 thymoma. Tumor tissue sections were immunohistochemically stained for MUC1 and GLUT1; meanwhile, some tumors were also stained with CKpan, TDT, CD5, and CD117. MUC1 was expressed in a total of 17 cases, with a positive rate of 77.27% (17/22) in thymic carcinoma and 9.52% (2/21) in type B3 thymoma, revealing a significant difference (p<0.0001). A significant difference (p<0.0001) was also shown for GLUT1, where the positive rates for thymic carcinoma and type B3 thymoma were 100% (22/22) and 42.86% (9/21), respectively. The expression of MUC1 was significantly correlated with GLUT1 (p<0.0001). Furthermore, GLUT1 staining sensitivity and specificity for thymic carcinoma were 100% (22/22) and 70.97% (22/31), respectively, while MUC1 staining sensitivity and specificity were 77.27% (17/22) and 89.47% (17/19), respectively. In conclusion, our study shows that MUC1 and GLUT1 staining may play a useful role in differentiating thymic carcinoma from type B3 thymoma, with high sensitivity and specificity.

Prognostic value of epidermal growth factor receptor mutations in resected non-small cell lung cancer: a systematic review with meta-analysis

BACKGROUND

The prognostic value of epidermal growth factor receptor (EGFR) mutations in resected non-small cell lung cancer (NSCLC) remains controversial. We performed a systematic review with meta-analysis to assess its role.

METHODS

Studies were identified via an electronic search on PubMed, Embase and Cochrane Library databases. Pooled hazard ratio (HR) for disease-free survival (DFS) and overall survival (OS) were calculated for meta-analysis.

RESULTS

There were 16 evaluated studies (n  =  3337) in the meta-analysis. The combined HR evaluating EGFR mutations on disease free survival was 0.96 (95% CI [0.79-1.16] P  =  0.65). The combined HR evaluating EGFR mutations on overall survival was 0.86 (95% CI [0.72-1.04] P  = 0.12). The subgroup analysis based on univariate and multivariate analyses in DFS and OS showed no statistically significant difference. There was also no statistically significant difference in DFS and OS of stage I NSCLC patients.

CONCLUSION

The systematic review with meta-analysis showed that EGFR mutations were not a prognostic factor in patients with surgically resected non-small cell lung cancer. Well designed prospective study is needed to confirm the result.

Hyperglycemia promotes K-Ras-induced lung tumorigenesis through BASCs amplification

Oncogenic K-Ras represents the most common molecular change in human lung adenocarcinomas, the major histologic subtype of non–small cell lung cancer (NSCLC). The presence of K-Ras mutation is associated with a poor prognosis, but no effective treatment strategies are available for K-Ras -mutant NSCLC. Epidemiological studies report higher lung cancer mortality rates in patients with type 2 diabetes. Here, we use a mouse model of K-Ras-mediated lung cancer on a background of chronic hyperglycemia to determine whether elevated circulating glycemic levels could influence oncogenic K-Ras-mediated tumor development. Inducible oncogenic K-Ras mouse model was treated with subtoxic doses of streptozotocin (STZ) to induce chronic hyperglycemia. We observed increased tumor mass and higher grade of malignancy in STZ treated diabetic mice analyzed at 4, 12 and 24 weeks, suggesting that oncogenic K-Ras increased lung tumorigenesis in hyperglycemic condition. This promoting effect is achieved by expansion of tumor-initiating lung bronchio-alveolar stem cells (BASCs) in bronchio-alveolar duct junction, indicating a role of hyperglycemia in the activity of K-Ras-transformed putative lung stem cells. Notably, after oncogene K-Ras activation, BASCs show upregulation of the glucose transporter (Glut1/Slc2a1), considered as an important player of the active control of tumor cell metabolism by oncogenic K-Ras. Our novel findings suggest that anti-hyperglycemic drugs, such as metformin, may act as therapeutic agent to restrict lung neoplasia promotion and progression.