Hypoxia boosts aerobic glycolysis of carcinoma：a complex process for tumor development

PFKP Lactylation Promotes the Ovarian Cancer Progression Through Targeting PTEN

Ovarian cancer (OC) ranks among the most prevalent malignancies affecting females globally and is a leading cause of cancer-related mortality in women. This study sought to elucidate the influence of phosphofructokinase P (PFKP) on the progression of OC. A cohort of sixty OC patients was enrolled. OC cells were exposed to both normoxic and hypoxic conditions. Expression levels of PFKP and phosphatase and tensin homolog (PTEN) were quantified using real time quantitative polymerase chain reaction (RT-qPCR) and Western blot analyses. Immunofluorescence confirmed these protein expression patterns. Glycolysis-related parameters, encompassing glucose uptake, extracellular lactate levels, extracellular acidification rates, and oxygen consumption rates, were assessed using commercially available kits. Lactylation status of PFKP was evaluated via immunoprecipitation followed by Western blot analysis. An OC xenograft mouse model was also established. Findings indicated elevated PFKP expression in OC tissues and cells. Additionally, PFKP knockdown attenuated glycolysis and counteracted the hypoxia-induced enhancement of glycolytic activity in OC cells. Mutation of the lysine (K) residue at position 392 diminished PFKP lactylation. Further investigations revealed that PFKP depletion upregulated PTEN expression in hypoxia-treated OC cells. Besides, PTEN suppression increased the glycolysis in hypoxia-treated OC cells. Animal study results demonstrated that PFKP inhibition curtailed OC tumor growth by modulating PTEN expression. Collectively, these results suggested that lactylation of PFKP at the K392 residue promoted glycolysis in OC cells by regulating PTEN, thereby facilitating the disease's progression.

Multi-omics-driven discovery of invasive patterns and treatment strategies in CA19-9 positive intrahepatic cholangiocarcinoma

BACKGROUND

Intrahepatic cholangiocarcinoma (ICC) is a malignant tumor with a poor prognosis, predominantly CA19-9 positive. High CA19-9 levels correlate with increased aggressiveness and worse outcomes. This study employs multi-omics analysis to reveal molecular features and identify therapeutic targets of CA19-9 positive ICC, aiming to support individualized treatment.

METHODS

Data from seven clinical cohorts, two whole-exome sequencing cohorts, six RNA sequencing/microarray cohorts, one proteomic cohort, 20 single-cell RNA sequencing samples, and one spatial transcriptome sample were analyzed. Key findings were validated on tissue microarrays from 52 ICC samples.

RESULTS

CA19-9 positive ICC exhibited poorer OS (median 24.1 v.s. 51.5 months) and RFS (median 11.7 v.s. 28.2 months) compared to negative group (all P < 0.05). Genomic analysis revealed a higher KRAS mutation frequency in the positive group and a greater prevalence of IDH1/2 mutations in the negative group (all P < 0.05). Transcriptomic analysis indicated upregulated glycolysis pathways in CA19-9 positive ICC. Single-cell analysis identified specific glycolysis-related cell subclusters associated with poor prognosis, including Epi_SLC2A1, CAF_VEGFA, and Mph_SPP1. Higher hypoxia in the CA19-9 positive group led to metabolic reprogramming and promoted these cells' formation. These cells formed interactive communities promoting epithelial-mesenchymal transition (EMT) and angiogenesis. Drug sensitivity analysis identified six potential therapeutic drugs.

CONCLUSIONS

This study systematically elucidated the clinical, genomic, transcriptomic, and immune features of CA19-9 positive ICC. It reveals glycolysis-associated cellular communities and their cancer-promoting mechanisms, enhancing our understanding of ICC and laying the groundwork for individualized therapeutic strategies.

Hypoxia-induced SHMT2 protein lactylation facilitates glycolysis and stemness of esophageal cancer cells

Esophageal cancer (EC) is a familiar digestive tract tumor with highly lethal. The hypoxic environment has been demonstrated to be a significant factor in modulating malignant tumor progression and is strongly associated with the abnormal energy metabolism of tumor cells. Serine hydroxymethyl transferase 2 (SHMT2) is one of the most frequently expressed metabolic enzymes in human malignancies. The study was designed to investigate the biological functions and regulation mechanisms of SHMT2 in EC under hypoxia. We conducted RT-qPCR to assess SHMT2 levels in EC tissues and cells (TE-1 and EC109). EC cells were incubated under normoxia and hypoxia, respectively, and altered SHMT2 expression was evaluated through RT-qPCR, western blot, and immunofluorescence. The biological functions of SHMT2 on EC cells were monitored by performing CCK-8, EdU, transwell, sphere formation, glucose uptake, and lactate production assays. The SHMT2 protein lactylation was measured by immunoprecipitation and western blot. In addition, SHMT2-interacting proteins were analyzed by bioinformatics and validated by rescue experiments. SHMT2 was notably upregulated in EC tissues and cells. Hypoxia elevated SHMT2 protein expression, augmenting EC cell proliferation, migration, invasion, stemness, and glycolysis. In addition, hypoxia triggered lactylation of the SHMT2 protein and enhanced its stability. SHMT2 knockdown impeded the malignant phenotype of EC cells. Further mechanistic studies disclosed that SHMT2 is involved in EC progression by interacting with MTHFD1L. Hypoxia-induced SHMT2 protein lactylation and upregulated its protein level, which in turn enhanced MTHFD1L expression and accelerated the malignant progression of EC cells.

Exploring the relationship between metabolism and immune microenvironment in osteosarcoma based on metabolic pathways

BACKGROUND

Metabolic remodeling and changes in tumor immune microenvironment (TIME) in osteosarcoma are important factors affecting prognosis and treatment. However, the relationship between metabolism and TIME needs to be further explored.

METHODS

RNA-Seq data and clinical information of 84 patients with osteosarcoma from the TARGET database and an independent cohort from the GEO database were included in this study. The activity of seven metabolic super-pathways and immune infiltration levels were inferred in osteosarcoma patients. Metabolism-related genes (MRGs) were identified and different metabolic clusters and MRG-related gene clusters were identified using unsupervised clustering. Then the TIME differences between the different clusters were compared. In addition, an MRGs-based risk model was constructed and the role of a key risk gene, ST3GAL4, in osteosarcoma cells was explored using molecular biological experiments.

RESULTS

This study revealed four key metabolic pathways in osteosarcoma, with vitamin and cofactor metabolism being the most relevant to prognosis and to TIME. Two metabolic pathway-related clusters (C1 and C2) were identified, with some differences in immune activating cell infiltration between the two clusters, and C2 was more likely to respond to two chemotherapeutic agents than C1. Three MRG-related gene clusters (GC1-3) were also identified, with significant differences in prognosis among the three clusters. GC2 and GC3 had higher immune cell infiltration than GC1. GC3 is most likely to respond to immune checkpoint blockade and to three commonly used clinical drugs. A metabolism-related risk model was developed and validated. The risk model has strong prognostic predictive power and the low-risk group has a higher level of immune infiltration than the high-risk group. Knockdown of ST3GAL4 significantly inhibited proliferation, migration, invasion and glycolysis of osteosarcoma cells and inhibited the M2 polarization of macrophages.

CONCLUSION

The metabolism of vitamins and cofactors is an important prognostic regulator of TIME in osteosarcoma, MRG-related gene clusters can well reflect changes in osteosarcoma TIME and predict chemotherapy and immunotherapy response. The metabolism-related risk model may serve as a useful prognostic predictor. ST3GAL4 plays a critical role in the progression, glycolysis, and TIME of osteosarcoma cells.

The essential molecular requirements for the transformation of normal cells into established cancer cells, with implications for a novel anti-cancer agent

BACKGROUND

Normal adult mammalian cells can respond to oncogenic somatic mutations by committing suicide through a well-described, energy dependent process termed apoptosis. Cancer cells avoid oncogene promoted apoptosis. Oncogenic somatic mutations are widely acknowledged to be the cause of the relentless unconstrained cell proliferation which characterises cancer. But how does the normal cell with the very first oncogenic mutation survive to proliferate without undergoing apoptosis?

NEW FINDINGS

The phenomena of malignant transformation by somatic mutation, apoptosis, aneuploidy, aerobic glycolysis and Cdk4 upregulation in carcinogenesis have each been extensively discussed separately in the literature but an overview explaining how they may be linked at the initiation of the cancer process has not previously proposed.

CONCLUSION

A hypothesis is presented to explain how in addition to the initial oncogenic mutation, the expression of certain key normal genes is, counter-intuitively, also required for successful malignant transformation from a normal cell to a cancer cell. The hypothesis provides an explanation for how the cyclic amphiphilic peptide HILR-056, derived from peptides with homology to a hexapeptide in the C-terminal region of Cdk4, kill cancer cells but not normal cell by necrosis rather than apoptosis.

Autophagy and Glycometabolic Reprograming in the Malignant Progression of Lung Cancer: A Review

Lung cancer is one of the leading causes of cancer-related deaths worldwide. However, there are currently limited treatment options that are widely available to patients with advanced lung cancer, and further research is required to inhibit or reverse disease progression more effectively. In lung and other solid tumor cancers, autophagy and glycometabolic reprograming are critical regulators of malignant development, including proliferation, drug resistance, invasion, and metastasis. To provide a theoretical basis for therapeutic strategies targeting autophagy and glycometabolic reprograming to prevent lung cancer, we review how autophagy and glycometabolism are regulated in the malignant development of lung cancer based on research progress in other solid tumors.

CircRBM33 downregulation inhibits hypoxia-induced glycolysis and promotes apoptosis of breast cancer cells via a microRNA-542-3p/HIF-1α axis

Many circRNAs are involved in the carcinogenesis of breast cancer (BCa) through the transcription of microRNAs (miRNAs) and mRNAs. This study investigated circRBM33 regulation of the miR-542-3p/hypoxia-inducible factor-1α (HIF-1α) axis in BCa. BCa clinical tissue samples were collected to test differential expressions of circRBM33, miR-542-3p, and HIF-1α. MCF-7 cells were subjected to normoxia or hypoxia and transfected with plasmids that regulated CircRBM33, miR-542-3p, and HIF-1α expression levels. Glycolysis was evaluated by measuring glucose consumption, lactic acid production, and protein expression of hexokinase 2, glucose transporter type 1 and lactic dehydrogenase A. Cell proliferation and apoptosis were also assessed, and the interactions between genes were explored. CircRBM33 and HIF-1α were upregulated, while miR-542-3p was downregulated in BCa tissue samples and cell lines. Hypoxia induced circRBM33 expression in BCa cells, which negatively regulated miR-542-3p expression. CircRBM33 knockdown or miR-542-3p rescue reduced glycolysis and proliferation and promoted apoptosis of BCa cells. MiR-542-3p inhibition rescued circRBM33 knockdown-mediated glycolysis, proliferation and apoptosis of BCa cells. MiR-542-3p targeted HIF-1α, and the overexpression of HIF-1α reversed the effect of miR-542-3p upregulation on glycolysis, proliferation, and apoptosis of BCa cells. Collectively, downregulating circRBM33 suppresses miR-542-3p-targeted HIF-1α expression, resulting in the inhibition of glycolysis and proliferation and the promotion of BCa cells’ apoptosis.