The value of expression of M2-PK and VEGF in patients with advanced gastric cancer

Nano-alkaline ion-excited NETs ablative eye drops promote ocular surface recovery

Neutrophil extracellular traps (NETs) promote neovascularization during the acute phase after ocular chemical injury, while the local inflammatory acidic environment delays post-injury repair. Currently, the mechanism of NETs promoting neovascularization has not been fully elucidated, and there is a lack of therapeutic strategies to effectively improve the local microenvironment for corneal repair. In this study, we validated the NETs-M2-angiogenic pathway after injury. Using transcriptomics sequencing and liquid-phase microarray assays, the intrinsic immune cascade mechanism of NETs inducing macrophage M2 polarization and releasing VEGF via PI3K/AKT was identified. Based on this pathology and the physiological need to improve the local inflammatory acidic environment and promote corneal repair, we organically integrated the alkaline ion-rich bioglass with the highly transmissive and highly adhesive filipin protein, and constructed NETs ablative gel eye drops (DMS) that can release DNase I and alkaline ions in a sustained manner. The eye drops restricted the inflammatory interaction of NETs with macrophages from the source, adhered to the corneal surface and continuously released alkaline ions to improve the local acidic inflammatory environment, providing a favorable immune microenvironment for corneal recovery. We established a cell co-culture system and a corneal alkali burn model to further validate the role of DMS in modulating the intrinsic immune cascade of neovascularization for corneal repair and the related mechanisms. In conclusion, based on the biological mechanism of NETs-M2-VEGF after corneal chemical injury, the present study designed eye drops for dual regulation of intrinsic immunity and the inflammatory acid environment, which not only further supplemented and improved the pathophysiological mechanism of corneal neovascularization after chemical injury, but also provided a new way of thinking about corneal regeneration after injury.

Fructose-1,6-bisphosphatase 2 represses cervical cancer progression via inhibiting aerobic glycolysis through promoting pyruvate kinase isozyme type M2 ubiquitination

Growing evidence has shown that aerobic glycolysis, as a hallmark of cancer cells, plays a crucial role in cervical cancer. The aim of the study is to uncover whether fructose-1,6-bisphosphatase 2 (FBP2) is involved in cervical cancer progression via the aerobic glycolysis pathway. FBP2 levels were determined by quantitative PCR (qPCR) and western blotting. Cell growth viability and apoptosis were tested by cell counting kit-8 (CCK-8) and flow cytometry assays. Immunoprecipitation assay was applied for the detection of the FBP2 effect on pyruvate kinase isozyme type M2 (PKM2) ubiquitination. FBP2 level was decreased in cervical cancer, which is closely linked to shorter overall survival. FBP2 decreased cell growth and aerobic glycolysis and increased cell apoptosis, as well as decreased PKM2 expression and increased its ubiquitination level. The above-mentioned roles of FBP2 were weakened followed by PKM2 overexpression. FBP2 inhibited cervical cancer cell growth via inhibiting aerobic glycolysis by inducing PKM2 ubiquitination.

Rev-erbα inhibits proliferation by reducing glycolytic flux and pentose phosphate pathway in human gastric cancer cells

Rev-erbα is a nuclear receptor, which regulates circadian rhythm, inflammatory responses and lipid metabolism. We previously showed Rev-erbα reduction in human gastric cancer, which is associated with TMN stages and poor prognosis. We hypothesized that Rev-erbα modulates proliferation via glycolytic flux and the pentose phosphate pathway (PPP) in gastric cancer. Knockdown of Rev-erbα significantly increased proliferation as well as glycolytic flux and the PPP in human gastric cancer cells. These effects were reduced by a Rev-erbα agonist GSK4112 in a dose-dependent manner. Furthermore, Rev-erbα was recruited on the promoters of PFKFB3 and G6PD genes, thereby inhibiting their gene transcription. GSK4112 treatment reduced PFKFB3 and G6PD gene expression, which was not affected by BMAL1 knockdown. Pharmacological inhibition of glycolysis and the PPP using corresponding PFKFB3 and G6PD inhibitors attenuated Rev-erbα knockdown-induced proliferation in gastric cancer cells. GSK4112 treatment was not able to reduce proliferation in SGC-7901 overexpressing both PFKFB3 and G6PD genes. Both PFKFB3 and G6PD were overexpressed in patients with gastric cancer, and positively correlated with the TMN stages. The PPP and glycolysis were enhanced in gastric cancer tissues of patients with low expression of Rev-erbα compared to the patients with high expression of Rev-erbα. In conclusion, Rev-erbα reduction causes gastric cancer progression by augmenting the PPP and glycolysis.

PKM2, function and expression and regulation

Pyruvate kinase (PK), as one of the key enzymes for glycolysis, can encode four different subtypes from two groups of genes, although the M2 subtype PKM2 is expressed mainly during embryonic development in normal humans, and is closely related to tissue repair and regeneration, with the deepening of research, the role of PKM2 in tumor tissue has received increasing attention. PKM2 can be aggregated into tetrameric and dimeric forms, PKM2 in the dimer state can enter the nuclear to regulate gene expression, the transformation between them can play an important role in tumor cell energy supply, epithelial-mesenchymal transition (EMT), invasion and metastasis and cell proliferation. We will use the switching effect of PKM2 in glucose metabolism as the entry point to expand and enrich the Warburg effect. In addition, PKM2 can also regulate each other with various proteins by phosphorylation, acetylation and other modifications, mediate the different intracellular localization of PKM2 and then exert specific biological functions. In this paper, we will illustrate each of these points.

Editor’s Pick: Pyruvate Kinase and Gastric Cancer: A Potential Marker

Gastric cancer is the second most common cause of cancer-related deaths worldwide, and the 5-year overall survival rate for advanced gastric cancer is ≤25%. Metabolism is a critical process for maintaining growth and other functions in cancer cells; in these cells, the metabolic process shifts from oxidative phosphorylation to aerobic glycolysis and the expression of pyruvate kinase (PK) splice isoform M2 (PKM2) is upregulated. A PubMed search focussing on PK in gastric cancer was conducted and 32 articles were initially collected; 12 articles were subsequently excluded from this review. PKM2 is responsible for tumour growth and invasion and correlates with short survival times and cancer differentiation. Pyruvate dehydrogenase kinase 1 is associated with cell proliferation, lymph node metastasis, and invasion. Measurement of PKM2 or pyruvate dehydrogenase kinase 1 in the blood or stools could be a good marker for gastric cancer in combination with the glycoprotein CA72-4. The review arose from the need for new biomarkers in the management of gastric cancer and had the primary objective of determining whether PK could be used as a marker to diagnose and monitor gastric cancer.

PKM2 in carcinogenesis and oncotherapy

Tumor cell metabolism is characterized by abundant glucose consumption and aerobic glycolysis. And pyruvate kinase M2 (PKM2) plays a decisive role in glycolysis, significantly contributing to the Warburg effect, tumor growth, angiogenesis, cell division, metastasis and apoptosis. To date, researchers have unraveled the potential of pyruvate kinase M2 as an antitumor target, which suggests a new orientation for oncotherapy. Herein, we focus on the role of pyruvate kinase M2 in tumor cell development and its function as a potential new therapeutic target for tumor treatment. Besides, research actuality on pyruvate kinase M2-dependent glycometabolism and signaling pathway in tumors is also summarized, providing valuable suggestions for further study in this field.

PFKFB3 was overexpressed in gastric cancer patients and promoted the proliferation and migration of gastric cancer cells

OBJECTIVE

Gastric cancer is one of the most common cancers worldwide, and the prognosis is still very poor due to the lack of specific and sensitive biomarkers. Aerobic glycolysis is one of the critical hallmarks of gastric cancer cells, and several glycolytic enzymes are highly expressed in gastric cancer patients. However, the expression and clinical significances of phosphofructokinase-2/fructose-2,6-bisphosphatase3 (PFKFB3, one of the glycolytic enzymes) in a large sample of gastric cancer patients remain unclear.

METHODS

The expression of PFKFB3 was detected in 134 gastric cancer patients by qRT-PCR, immunohistochemistry, and western blot analyses. The correlation between PFKFB3 expression and clinicopathological factors was analyzed by χ 2 test. In addition, we also analyzed whether the knockdown of PFKFB3 by siRNAs could inhibit the ability of gastric cancer cells (MGC-803 and AGS) to proliferate and migrate by MTT analysis and transwell analyses.

RESULTS

PFKFB3 was highly expressed in 81.3% (109/134) of gastric cancer patients. The overexpression of PFKFB3 was associated with lymph node metastasis (P = 0.045) and TNM stage (P = 0.033). Knockdown of PFKFB3 by siRNAs significantly inhibited the proliferation and migration abilities of gastric cancer cells.

CONCLUSION

Our data suggest that PFKFB3 might be a potential biomarker for gastric cancer and anti-neoplastic targeting gene.

Pyruvate kinase M2 overexpression and poor prognosis in solid tumors of digestive system: evidence from 16 cohort studies

Purpose

The expression of pyruvate kinase M2 (PKM2) has been linked to tumor formation and invasion. Specifically, the relationship between high PKM2 expression and prognosis has been evaluated in solid tumors of digestive system. However, the prognostic value of PKM2 remains controversial.

Methods

A literature search of PubMed, Embase, and Cochrane databases was conducted until October 2015. The end point focused on overall survival (OS). The pooled hazard ratio (HR) or odds ratio and the 95% confidence intervals were calculated to correlate PKM2 overexpression with OS and clinicopathological characteristics by employing fixed- or random-effects models, depending on the heterogeneity of the included studies.

Results

We identified 18 cohorts in 16 studies involving 2,812 patients for this meta-analysis. Overall, the combined HR for OS in all tumor types was 1.74 (1.44–2.11; P<0.001). When stratified by tumor type, the influence of PKM2 expression on poor prognosis was also found in gastric cancer (HR =1.54 [1.08–2.21], P=0.018), esophageal squamous cell carcinoma (HR =1.71 [1.38–2.12], P<0.001), hepatocellular cancer (HR =1.92 [1.52–2.42], P<0.001), biliary cancer (HR =2.11 [1.50–2.95], P<0.001), and oral cancer (HR =3.49 [1.97–6.18], P<0.001), but not in pancreatic ductal adenocarcinoma (HR =1.03 [0.28–3.76], P=0.968). Furthermore, PKM2 overexpression had a negative effect on the late clinical stage of all tumor types except for pancreatic ductal adenocarcinoma. The high density of PKM2 overexpression was significantly associated with some clinical characteristics in different cancer types, such as tumor stage, modal metastasis, and tumor size.

Conclusion

Our findings revealed significant association of PKM2 overexpression with OS and certain clinicopathological features in solid tumors of digestive system, thereby suggesting that PKM2 might be an indicator of poor prognosis in digestive system cancers.

Peptidomimetic suppresses proliferation and invasion of gastric cancer cells by fibroblast growth factor 2 signaling cascade blockage

Fibroblast growth factor 2 (FGF2) is closely involved in a variety of tumors, including gastric cancer (GC). FGF2 inhibitors exert good antitumor activity, but no FGF2 inhibitor has been employed for clinical use. To obtain a low-toxicity, stable peptidomimetic (called P29) target to FGF2, the affinity between P29 and FGF2 was detected by surface plasmon resonance. The stability of P29 was measured by high performance liquid chromatography. MTT assay and transwell assay were used to access the proliferative and invasive ability of GC cells, respectively. Western blot assay and flow cytometric analysis were applied to study the mechanism of P29. P29 possessed high affinity with FGF2 and a longer half-life in vitro. P29 suppressed the FGF2-induced proliferation of GC cells. It also inhibited the phosphorylation of FRS2, ERK1/2, and AKT triggered by FGF2 in GC. In addition, P29 blocked GC cell transformation from the G1/G0 phase to the S phase and weakened the invasive capability of GC cells. In this paper, we present a novel FGF2 inhibitor that could exert improved anticancer effect in GC in vitro.

Overexpression of pyruvate kinase M2 associates with aggressive clinicopathological features and unfavorable prognosis in oral squamous cell carcinoma

Abnormal glucose metabolism mediated by pyruvate kinase M2 (PKM2) fuels cancer overgrowth and propagation. However, its expression and oncogenic roles in in oral squamous cell carcinoma (OSCC) remains incompletely known. Here, we aimed to investigate the expression of PKM2, its prognostic values and oncogenic functions using 7,12-dimethyl-1,2-bezan-tracene (DMBA)-induced hamster buccal pouch SCC model, primary OSCC specimens as well as in vitro cellular assays. We found that in DMBA-induced OSCC model, negative PKM2 expression was commonly observed in normal epithelial, while more PKM2 abundance was detected in hyperplasia, dysplasia and SCC. Overexpression of PKM2 in a major fraction of OSCC significantly associated with tumor size (P = 0.027), cervical node metastasis (P = 0.004) and clinical stages (P = 0.000). Patients with increased PKM2 had remarkably reduced overall and disease-free survival. Multivariate survival analysis further revealed that PKM served as a critical independent prognostic factor for patients' overall survival. Furthermore, impaired cell proliferation and migration, and reduced apoptosis were detected upon PKM2 knockdown in HN4 and HN12 cells. Taken together, our findings reveal that PKM2 is critically involved in OSCC initiation and progression probably by promoting cell proliferation and migration as well as reducing apoptosis. Its overexpression correlates with aggressive clinicopathological features and poor patients' outcome.

The multifaceted regulation and functions of PKM2 in tumor progression

Tumor cells undergo metabolic rewiring from oxidative phosphorylation towards aerobic glycolysis to maintain the increased anabolic requirements for cell proliferation. It is widely accepted that specific expression of the M2 type pyruvate kinase (PKM2) in tumor cells contributes to this aerobic glycolysis phenotype. To date, researchers have uncovered myriad forms of functional regulation for PKM2, which confers a growth advantage on the tumor cells to enable them to adapt to various microenvironmental signals. Here the richness of our understanding on the modulations and functions of PKM2 in tumor progression is reviewed, and some new insights into the paradoxical expression and functional differences of PKM2 in distinct cancer types are offered.

Diagnostic and prognostic serum marker of cholangiocarcinoma (Review)

Cholangiocarcinoma (CCA) is a fatal disease that is typically diagnosed late and treated ineffectively. As the morbidity and mortality rates for CCA rise markedly, patietns with CCA currently have a poor prognosis. However, if it were possible to diagnose CCA early while effective treat methods are available, CCA patients would achieve a better quality of life. Therefore, preventing the process of CCA in the early stages is an urgent problem to solve. An accurate, quick and safe method to diagnose early-stage CCA is required. The present review discusses the risk factors, status of research and certain serum markers of CCA. The sensitivity and specificity of these markers differ from each other. To explore the more accurate serum markers may be a novel direction and method for the diagnosis of CCA in laboratory medicine in the future.

Overexpression of metabolic markers PKM2 and LDH5 correlates with aggressive clinicopathological features and adverse patient prognosis in tongue cancer

AIMS

Pyruvate kinase M2 (PKM2) and lactate dehydrogenase 5 (LDH5) are two metabolic and oncogenic markers of cancer. In this study, we sought to investigate their expression patterns and prognostic value in tongue squamous cell carcinoma (TSCC).

METHODS AND RESULTS

The expression and subcellular localization of PKM2 and LDH5 in TSCC cell lines were determined by Western blot and immunofluorescence. PKM2 and LDH5 abundance was examined by immunohistochemistry in 63 TSCC tumour specimens; their association with multiple clinicopathological parameters and overall patient survival was assessed. The protein levels of PKM2 and LDH5 were both significantly higher in TSCC cells than in an immortalized oral epithelial cell line. Overexpression of PKM2 associated significantly with cervical node metastasis (P = 0.0373), while elevated LDH5 levels correlated significantly with tumour size (P = 0.0094), pathological grade (P = 0.0052), cervical node metastasis (P = 0.0023) and clinical stage (P = 0.0024). Patients with tumours showing an increase in either PKM2 or LDH5 expression displayed significantly reduced overall survival, while patients with tumours overexpressing both proteins showed the worst prognosis with lowest overall survival. Furthermore, PKM2 and LDH5 were identified as independent prognostic predictors for overall patient survival in TSCC.

CONCLUSION

Our data indicate that overexpression of PKM2 and LDH5 associates with key clinicopathological features and unfavourable prognosis in TSCC.