Homeodomain-interacting protein kinase 2 suppresses proliferation and aerobic glycolysis via ERK/cMyc axis in pancreatic cancer

Inactivation of HIPK2 attenuates KRASG12D activity and prevents pancreatic tumorigenesis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) features KRAS mutations in approximately 90% of human cases and excessive stromal response, termed desmoplastic reaction. Oncogenic KRAS drives pancreatic carcinogenesis by acting on both epithelial cells and tumor microenvironment (TME). We have previously shown that Homeodomain-Interacting Protein Kinase 2 (HIPK2) cooperates with KRAS in sustaining ERK1/2 phosphorylation in human colorectal cancers. Here, we investigated whether HIPK2 contributes to oncogenic KRAS-driven tumorigenesis in vivo, in the onset of pancreatic cancer.

METHODS

We employed an extensively characterized model of KRASG12D-dependent preinvasive PDAC, the Pdx1-Cre;LSL-KRasG12D/+ (KC) mice. In these mice, HIPK2 was inhibited by genetic knockout in the pancreatic epithelial cells (KCH-/-) or by pharmacologic inactivation with the small molecule 5-IodoTubercidin (5-ITu). The development of preneoplastic acinar-to-ductal metaplasia (ADM), intraepithelial neoplasia (PanIN), and their associated desmoplastic reaction were analyzed.

RESULTS

In Hipk2-KO mice (KCH-/-), ERK phosphorylation was lowered, the appearance of ADM was slowed down, and both the number and pathologic grade of PanIN were reduced compared to Hipk2-WT KC mice. The pancreatic lesion phenotype in KCH-/- mice was characterized by abundant collagen fibers and reduced number of αSMA+ and pSTAT3+ desmoplastic cells. These features were reminiscent of the recently described human "deserted" sub-TME, poor in cells, rich in matrix, and associated with tumor differentiation. In contrast, the desmoplastic reaction of KC mice resembled the "reactive" sub-TME, rich in stromal cells and associated with tumor progression. These observations were confirmed by the pharmacologic inhibition of HIPK2 in KC mice.

CONCLUSION

This study demonstrates that HIPK2 inhibition weakens oncogenic KRAS activity and pancreatic tumorigenesis providing a rationale for testing HIPK2 inhibitors to mitigate the incidence of PDAC development in high-risk individuals.

HIPK2 in Colon Cancer: A Potential Biomarker for Tumor Progression and Response to Therapies

Colon cancer, one of the most common and fatal cancers worldwide, is characterized by stepwise accumulation of specific genetic alterations in tumor suppressor genes or oncogenes, leading to tumor growth and metastasis. HIPK2 (homeodomain-interacting protein kinase 2) is a serine/threonine protein kinase and a "bona fide" oncosuppressor protein. Its activation inhibits tumor growth mainly by promoting apoptosis, while its inactivation increases tumorigenicity and resistance to therapies of many different cancer types, including colon cancer. HIPK2 interacts with many molecular pathways by means of its kinase activity or transcriptional co-repressor function modulating cell growth and apoptosis, invasion, angiogenesis, inflammation and hypoxia. HIPK2 has been shown to participate in several molecular pathways involved in colon cancer including p53, Wnt/β-catenin and the newly identified nuclear factor erythroid 2 (NF-E2) p45-related factor 2 (NRF2). HIPK2 also plays a role in tumor-host interaction in the tumor microenvironment (TME) by inducing angiogenesis and cancer-associated fibroblast (CAF) differentiation. The aim of this review is to assess the role of HIPK2 in colon cancer and the underlying molecular pathways for a better understanding of its involvement in colon cancer carcinogenesis and response to therapies, which will likely pave the way for novel colon cancer therapies.

A positive feedback loop between PFKP and c-Myc drives head and neck squamous cell carcinoma progression

BACKGROUND

The aberrant expression of phosphofructokinase-platelet (PFKP) plays a crucial role in the development of various human cancers by modifying diverse biological functions. However, the precise molecular mechanisms underlying the role of PFKP in head and neck squamous cell carcinoma (HNSCC) are not fully elucidated.

METHODS

We assessed the expression levels of PFKP and c-Myc in tumor and adjacent normal tissues from 120 HNSCC patients. A series of in vitro and in vivo experiments were performed to explore the impact of the feedback loop between PFKP and c-Myc on HNSCC progression. Additionally, we explored the therapeutic effects of targeting PFKP and c-Myc in HNSCC using Patient-Derived Organoids (PDO), Cell Line-Derived Xenografts, and Patients-Derived Xenografts.

RESULTS

Our findings indicated that PFKP is frequently upregulated in HNSCC tissues and cell lines, correlating with poor prognosis. Our in vitro and in vivo experiments demonstrate that elevated PFKP facilitates cell proliferation, angiogenesis, and metastasis in HNSCC. Mechanistically, PFKP increases the ERK-mediated stability of c-Myc, thereby driving progression of HNSCC. Moreover, c-Myc stimulates PFKP expression at the transcriptional level, thus forming a positive feedback loop between PFKP and c-Myc. Additionally, our multiple models demonstrate that co-targeting PFKP and c-Myc triggers synergistic anti-tumor effects in HNSCC.

CONCLUSION

Our study demonstrates the critical role of the PFKP/c-Myc positive feedback loop in driving HNSCC progression and suggests that simultaneously targeting PFKP and c-Myc may be a novel and effective therapeutic strategy for HNSCC.

CircRNAs in Pancreatic Cancer: New Tools for Target Identification and Therapeutic Intervention

We have reviewed the literature for circular RNAs (circRNAs) with efficacy in preclinical pancreatic-cancer related in vivo models. The identified circRNAs target chemoresistance mechanisms (n=5), secreted proteins and transmembrane receptors (n=15), transcription factors (n=9), components of the signaling- (n=11), ubiquitination- (n=2), autophagy-system (n=2), and others (n=9). In addition to identifying targets for therapeutic intervention, circRNAs are potential new entities for treatment of pancreatic cancer. Up-regulated circRNAs can be inhibited by antisense oligonucleotides (ASO), small interfering RNAs (siRNAs), short hairpin RNAs (shRNAs) or clustered regularly interspaced short-palindromic repeats-CRISPR associated protein (CRISPR-CAS)-based intervention. The function of down-regulated circRNAs can be reconstituted by replacement therapy using plasmids or virus-based vector systems. Target validation experiments and the development of improved delivery systems for corresponding agents were examined.

Fundamental insights and molecular interactions in pancreatic cancer: Pathways to therapeutic approaches

The gastrointestinal tract can be affected by a number of diseases that pancreatic cancer (PC) is a malignant manifestation of them. The prognosis of PC patients is unfavorable and because of their diagnosis at advanced stage, the treatment of this tumor is problematic. Owing to low survival rate, there is much interest towards understanding the molecular profile of PC in an attempt in developing more effective therapeutics. The conventional therapeutics for PC include surgery, chemotherapy and radiotherapy as well as emerging immunotherapy. However, PC is still incurable and more effort should be performed. The molecular landscape of PC is an underlying factor involved in increase in progression of tumor cells. In the presence review, the newest advances in understanding the molecular and biological events in PC are discussed. The dysregulation of molecular pathways including AMPK, MAPK, STAT3, Wnt/β-catenin and non-coding RNA transcripts has been suggested as a factor in development of tumorigenesis in PC. Moreover, cell death mechanisms such as apoptosis, autophagy, ferroptosis and necroptosis demonstrate abnormal levels. The EMT and glycolysis in PC cells enhance to ensure their metastasis and proliferation. Furthermore, such abnormal changes have been used to develop corresponding pharmacological and nanotechnological therapeutics for PC.

Potential Effects of NO-Induced Hypoxia-Inducible Factor-1α on Yak Meat Tenderness during Post-Mortem Aging

The objective of this study was to investigate the mechanism underlying nitric oxide (NO)-induced hypoxia-inducible factor-1α (HIF-1α) and its impact on yak muscle tenderness during post-mortem aging. The Longissimus thoracis et lumborum (LTL) muscle of yak were incubated at 4 °C for 0, 3, 6, 9, 12, 24, and 72 h after treatment with 0.9% saline, NO activator, or a combination of the NO activator and an HIF-1α inhibitor. Results indicated that elevated NO levels could increase HIF-1α transcription to achieve stable expression of HIF-1α protein (P < 0.05). Additionally, elevated NO triggered HIF-1α S-nitrosylation, which further upregulated the activity of key glycolytic enzymes, increased glycogen consumption, accelerated lactic acid accumulation, and decreased pH (P < 0.05). These processes eventually improved the tenderness of yak muscle during post-mortem aging (P < 0.05). The results demonstrated that NO-induced activation of HIF-1α S-nitrosylation enhanced glycolysis during post-mortem aging and provided a possible pathway for improving meat tenderness.

LCN2 Promotes Proliferation and Glycolysis by Activating the JAK2/STAT3 Signaling Pathway in Hepatocellular Carcinoma

This study aimed to explore the molecular mechanism of LCN2 regulating aerobic glycolysis on abnormal proliferation of HCC cells. Based on the prediction of GEPIA database, the expression levels of LCN2 in hepatocellular carcinoma tissues were detected by RT-qPCR analysis, western blot, and immunohistochemical staining, respectively. In addition, CCK-8 kit, clone formation, and EdU staining were used to analyze the effect of LCN2 on the proliferation of hepatocellular carcinoma cells. Glucose uptake and lactate production were detected using kits. In addition, western blot was used to detect the expressions of aerobic glycolysis-related proteins. Finally, western blot was used to detect the expressions of phosphorylation of JAK2 and STAT3. We found LCN2 was upregualted in hepatocellular carcinoma tissues. CCK-8 kit, clone formation, and EdU staining results showed that LCN2 could promote the proliferation in hepatocellular carcinoma cells (Huh7 and HCCLM3 cells). Western blot results and kits confirmed that LCN2 significantly promotes aerobic glycolysis in hepatocellular carcinoma cells. Western blot results showed that LCN2 could significantly upregulate the phosphorylation of JAK2 and STAT3. Our results indicated that LCN2 activated the JAK2/STAT3 signaling pathway, promoted aerobic glycolysis, and accelerated malignant proliferation of hepatocellular carcinoma cells.

Exosome-transmitted hsa_circ_0012634 suppresses pancreatic ductal adenocarcinoma progression through regulating miR-147b/HIPK2 axis

Circular RNA (circRNA) has been confirmed to play a vital role in pancreatic ductal adenocarcinoma (PDAC) progression. However, the function and regulatory mechanism of hsa_circ_0012634 in PDAC progression remain unclear. Quantitative real-time PCR was used to measure the expression of hsa_circ_0012634, microRNA (miR)-147b and homeodomain interacting protein kinase 2 (HIPK2). Cell function was assessed by cell counting kit 8 assay, EdU assay, colony formation assay and flow cytometry. Glucose uptake and lactate production were evaluated to determine cell glycolysis ability. Protein expression was examined by western blot analysis. RNA interaction was confirmed by RNA pull-down assay and dual-luciferase reporter assay. Exosomes were isolated from serums and cell culture supernatant using ultracentrifugation and identified by transmission electron microscopy. Animal experiments were conducted using nude mice. Hsa_circ_0012634 was downregulated in PDAC tissues and cells, and its overexpression suppressed PDAC cell proliferation, glycolysis and enhanced apoptosis. MiR-147b was targeted by hsa_circ_0012634, and its inhibitors repressed PDAC cell growth and glycolysis. HIPK2 could be targeted by miR-147b, and hsa_circ_0012634 regulated miR-147b/HIPK2 to suppress PDAC cell progression. Hsa_circ_0012634 was lowly expressed in serum exosomes of PDAC patients. Exosomal hsa_circ_0012634 inhibited PDAC cell growth and glycolysis in vitro, as well as tumorigenesis in vivo. Exosomal hsa_circ_0012634 restrained PDAC progression via the miR-147b/HIPK2 pathway, confirming that hsa_circ_0012634 might serve as a diagnosis and treatment biomarker for PDAC.

miR-147b is an oncomiR acting synergistically with HIPK2 to promote pancreatic carcinogenesis

MicroRNAs (miRs, miRNAs) are known players in the regulatory network of pancreatic tumorigenesis, but the downstream effectors remain poorly characterized. This study addressed this issue based on in silico prediction, in vitro experiments, and in vivo validation. The differentially expressed PCa-related miRNAs and bioinformatics tools predicted downstream regulators. The expression of miR-147b was examined in PCa cell lines. Putative targets of miR-147b were predicted by a publicly available database and confirmed by luciferase activity assay. Mimic/inhibitor, siRNA/overexpression plasmid, or pifithrin-α (p53 inhibitor) were delivered into PCa cells to assess the effect of miR-147b, HIPK2, and p53 on malignant phenotypes of PCa cells. AntagomiR-147b and shRNA targeting HIPK2 were introduced to xenograft-bearing nude mice for in vivo experiments. The expression of miR-147b was significantly increased in PCa cell lines. Ectopic expression of miR-147b promoted the malignant phenotypes of PCa cells and inhibited their apoptosis. HIPK2 was confirmed as a target gene of miR-147b. Inhibiting miR-147b could promote HIPK2 expression and potentially activate the p53 pathway, inhibiting PCa cell growth. In vivo experiments suggested that miR-147b inhibition suppressed the growth of xenograft tumors in nude mice, while HIPK2 knockdown counteracted its effect. Collectively, our work reveals a novel miR-147b-mediated carcinogenic regulatory network in PCa that may be a viable target for PCa treatment.

Lactate-induced protein lactylation: A bridge between epigenetics and metabolic reprogramming in cancer

Lactate is not only an endpoint of glycolysis but is gradually being discovered to play the role of a universal metabolic fuel for energy via the 'lactate shuttle' moving between cells and transmitting signals. The glycolytic-dependent metabolism found in tumours and fast-growing cells has made lactate a pivotal player in energy metabolism reprogramming, which enables cells to obtain abundant energy in a short time. Moreover, lactate can provide favourable conditions for tumorigenesis by shaping the acidic tumour microenvironment, recruiting immune cells, etc. and the recently discovered lactate-induced lactylation moves even further on pro-tumorigenesis mechanisms of lactate production, circulation and utilization. As with other epigenetic modifications, lactylation can modify histone proteins to alter the spatial configuration of chromatin, affect DNA accessibility and regulate the expression of corresponding genes. What's more, the degree of lactylation is inseparable from the spatialized lactate concentration, which builds a bridge between epigenetics and metabolic reprogramming. Here, we review the important role of lactate in energy reprogramming, summarize the latest finding of lactylation in tumorigenesis and try to explore therapeutic strategies in oncotherapy that can kill two birds with one stone.

Knockdown of UBQLN1 Functions as a Strategy to Inhibit CRC Progression through the ERK-c-Myc Pathway

PURPOSE

Colorectal cancer (CRC) is characterized by the absence of obvious symptoms in the early stage. Due to the high rate of late diagnosis of CRC patients, the mortality rate of CRC is higher than that of other malignant tumors. Accumulating evidence has demonstrated that UBQLN1 plays an important role in many biological processes. However, the role of UBQLN1 in CRC progression is still elusive.

METHODS AND RESULTS

we found that UBQLN1 was significantly highly expressed in CRC tissues compared with normal tissues. Enhanced/reduced UBQLN1 promoted/inhibited CRC cell proliferation, colony formation, epithelial-mesenchymal transition (EMT) in vitro, and knockdown of UBQLN1 inhibited CRC cells' tumorigenesis and metastasis in nude mice in vivo. Moreover, the knockdown of UBQLN1 reduced the expression of c-Myc by downregulating the ERK-MAPK pathway. Furthermore, the elevation of c-Myc in UBQLN1-deficient cells rescued proliferation caused by UBQLN1 silencing.

CONCLUSIONS

Knockdown of UBQLN1 inhibits the progression of CRC through the ERK-c-Myc pathway, which provides new insights into the mechanism of CRC progression. UBQLN1 may be a potential prognostic biomarker and therapeutic target of CRC.

Identification of a Novel Gene Signature with DDR and EMT Difunctionalities for Predicting Prognosis, Immune Activity, and Drug Response in Breast Cancer

Breast cancer, with an overall poor clinical prognosis, is one of the most heterogeneous cancers. DNA damage repair (DDR) and epithelial-mesenchymal transition (EMT) have been identified to be associated with cancer's progression. Our study aimed to explore whether genes with both functions play a more crucial role in the prognosis, immune, and therapy response of breast cancer patients. Based on the Cancer Genome Atlas (TCGA) cancer database, we used LASSO regression analysis to identify the six prognostic-related genes with both DDR and EMT functions, including TP63, YWHAZ, BRCA1, CCND2, YWHAG, and HIPK2. Based on the six genes, we defined the risk scores of the patients and reasonably analyzed the overall survival rate between the patients with the different risk scores. We found that overall survival in higher-risk-score patients was lower than in lower-risk-score patients. Subsequently, further GO and KEGG analyses for patients revealed that the levels of immune infiltration varied for patients with high and low risk scores, and the high-risk-score patients had lower immune infiltration's levels and were insensitive to treatment with chemotherapeutic agents. Furthermore, the Gene Expression Omnibus (GEO) database validated our findings. Our data suggest that TP63, YWHAZ, BRCA1, CCND2, YWHAG, and HIPK2 can be potential genetic markers of prognostic assessment, immune infiltration and chemotherapeutic drug sensitivity in breast cancer patients.

Metabolic reprogramming of immune cells in pancreatic cancer progression

Abnormal intracellular metabolism not only provides nutrition for tumor occurrence and development, but also sensitizes the function of various immune cells in the immune microenvironment to promote tumor immune escape. This review discusses the emerging role of immune cells in the progress of pancreatic cancer, acrossing metabolic reprogramming and key metabolic pathways present in different immune cell types. At present, the hotspots of metabolic reprogramming of immune cells in pancreatic cancer progression mainly focuses on glucose metabolism, lipid metabolism, tricarboxylic acid cycle and amino acid metabolism, which affect the function of anti-tumor immune cells and immunosuppressive cells in the microenvironment, such as macrophages, dendritic cells, T cells, myeloid-derived suppressor cells, neutrophils and B cells by a series of key metabolic signaling pathways, such as PI3K/AKT, mTOR, AMPK, HIF-1α, c-Myc and p53. Drugs that target the tumor metabolism pathways for clinical treatment of pancreatic cancer are also systematically elaborated, which may constitute food for others' projects involved in clinical anti-cancer research.

HIPK2 in cancer biology and therapy: Recent findings and future perspectives

Homeodomain-interacting protein kinase 2 (HIPK2) is a serine-threonine kinase that phosphorylates and regulates a plethora of transcriptional regulators and chromatin modifiers. The heterogeneity of its interactome allows HIPK2 to modulate several cellular processes and signaling pathways, ultimately regulating cell fate and proliferation. Because of its p53-dependent pro-apoptotic activity and its downregulation in many tumor types, HIPK2 is traditionally considered a bone fide tumor suppressor gene. However, recent findings revealed that the role of HIPK2 in the pathogenesis of cancer is much more complex, ranging from tumor suppressive to oncogenic, strongly depending on the cellular context. Here, we review the very recent data emerged in the last years about the involvement of HIPK2 in cancer biology and therapy, highlighting the various alterations of this kinase (downregulation, upregulation, mutations and/or delocalization) in dependence on the cancer types. In addition, we discuss the recent advancement in the understanding the tumor suppressive and oncogenic functions of HIPK2, its role in establishing the response to cancer therapies, and its regulation by cancer-associated microRNAs. All these data strengthen the idea that HIPK2 is a key player in many types of cancer; therefore, it could represent an important prognostic marker, a factor to predict therapy response, and even a therapeutic target itself.

Caudatin blocks the proliferation, stemness and glycolysis of non-small cell lung cancer cells through the Raf/MEK/ERK pathway

CONTEXT

The antitumor effects of caudatin have been explored in multiple cancers, but the research on lung cancer has not been fully understood.

OBJECTIVE

We explored the effects of caudatin on non-small cell lung cancer (NSCLC) in vitro and in vivo.

MATERIALS AND METHODS

In the in vitro experiments, 0, 25, 50 and 100 μM of caudatin were selected to examine the effects on stemness and glycolysis. Subcutaneous tumour xenografts were constructed by injecting the nude mice (BALB/C) with 5 × 10⁶ H1299 cells. In the in vivo experiments, all nude mice were divided into the caudatin group (50 mg/kg/day, n = 5) and the sham group (equal amount of DMSO, n = 5).

RESULTS

The IC₅₀ of caudatin for H1299 and H520 cells was 44.68 μM and 69.37 μM, respectively. Compared with caudatin 0 μM group, cell apoptosis rate was increased about 10 times and cell stemness was decreased by 75-85% in caudatin 100 μM group. Glucose uptake (65-80% reduction), lactic acid production (75-80% reduction), ATP level (70-80% reduction) and the expression of HK2 and LDHA (75-85% reduction) were decreased in caudatin 100 μM group. The expression of Raf/MEK/ERK pathway related proteins was decreased to 20-25% by caudatin. Tumour weight (about 70% reduction) and the expression of stemness, glycolysis and Raf/MEK/ERK pathway related proteins (about 50-75% reduction) were suppressed by caudatin in vivo.

DISCUSSION AND CONCLUSIONS

We revealed that caudatin blocked stemness and glycolysis in NSCLC for the first time. More experiments about exact dosage of caudatin in vivo should be conducted.

miR-4653-3p overexpression is associated with a poor prognosis of pancreatic ductal adenocarcinoma via HIPK2 downregulation

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignant tumor. Several upregulated and downregulated microRNAs (miRNAs) are associated with invasiveness, tumorigenesis, and prognosis of PDAC. Herein, using in situ hybridization, we evaluated miR-4653-3p expression and pancreatic intraepithelial neoplasia (PanIN) and the association between miR-4653-3p expression and clinicopathological factors in PDAC patients. The miR-4653-3p target was also identified. Ninety PDAC cases, including 30 each with normal pancreatic ducts, low-grade PanINs, and high-grade PanINs, were evaluated. miR-4653-3p expression increased in the order-normal pancreatic duct, low-grade PanIN, high-grade PanIN, and PDAC-with no expression detected in normal pancreatic duct. High expression significantly correlated with advanced pathological T stage, lymph node metastasis, advanced Union for International Cancer Control stage, perineural invasion, venous involvement, and shorter overall and disease-specific survival. Homeodomain Interacting Protein Kinase 2 (HIPK2) was identified as a miR-4653-3p target based on mRNA microarray analysis and database screening. In MIA PaCa-2 cells, miR-4653-3p significantly downregulated HIPK2 expression. HIPK2 expression, unlike that of miR-4653-3p, decreased in the order-normal pancreatic duct, low-grade PanIN, high-grade PanIN, and PDAC. Low HIPK2 expression was associated with shorter overall and disease-specific survival in PDAC patients. Thus, miR-4653-3p associates with tumorigenesis and worse prognosis, partly by reducing HIPK2 expression.

Combining Single-Cell and Transcriptomic Data Revealed the Prognostic Significance of Glycolysis in Pancreatic Cancer

Background: Pancreatic cancer (PC), the most common fatal solid malignancy, has a very dismal prognosis. Clinical computerized tomography (CT) and pathological TNM staging are no longer sufficient for determining a patient’s prognosis. Although numerous studies have suggested that glycolysis is important in the onset and progression of cancer, there are few publications on its impact on PC.

Methods: To begin, the single-sample gene set enrichment analysis (ssGSEA) approach was used to quantify the glycolysis pathway enrichment fraction in PC patients and establish its prognostic significance. The genes most related to the glycolytic pathway were then identified using weighted gene co-expression network analysis (WGCNA). The glycolysis-associated prognostic signature in PC patients was then constructed using univariate Cox regression and lasso regression methods, which were validated in numerous external validation cohorts. Furthermore, we investigated the activation of the glycolysis pathway in PC cell subtypes at the single-cell level, performed a quasi-time series analysis on the activated cell subtypes and then detected gene changes in the signature during cell development. Finally, we constructed a decision tree and a nomogram that could divide the patients into different risk subtypes, according to the signature score and their different clinical characteristics and assessed the prognosis of PC patients.

Results: Glycolysis plays a risky role in PC patients. Our glycolysis-related signature could effectively discriminate the high-risk and low-risk patients in both the trained cohort and the independent externally validated cohort. The survival analysis and multivariate Cox analysis indicated this gene signature to be an independent prognostic factor in PC. The prognostic ROC curve analysis suggested a high accuracy of this gene signature in predicting the patient prognosis in PC. The single-cell analysis suggested that the glycolytic pathway may be more activated in epithelial cells and that the genes in the signature were also mainly expressed in epithelial cells. The decision tree analysis could effectively identify patients in different risk subgroups, and the nomograms clearly show the prognostic assessment of PC patients.

Conclusion: Our study developed a glycolysis-related signature, which contributes to the risk subtype assessment of patients with PC and to the individualized management of patients in the clinical setting.

Glycometabolic rearrangements-aerobic glycolysis in pancreatic ductal adenocarcinoma (PDAC): roles, regulatory networks, and therapeutic potential

INTRODUCTION

Glycometabolic rearrangements (aerobic glycolysis) is a hallmark of pancreatic ductal adenocarcinoma (PDAC) and contributes to tumorigenesis and progression through numerous mechanisms. The targeting of aerobic glycolysis is recognized as a potential therapeutic strategy which offers the possibility of improving treatment outcomes for PDAC patients.

AREAS COVERED

In this review, the role of aerobic glycolysis and its regulatory networks in PDAC are discussed. The targeting of aerobic glycolysis in PDAC is examined, and its therapeutic potential is evaluated. The relevant literature published from 2001 to 2021 was searched in databases including PubMed, Scopus, and Embase.

EXPERT OPINION

Regulatory networks of aerobic glycolysis in PDAC are based on key factors such as c-Myc, hypoxia-inducible factor 1α, the mammalian target of rapamycin pathway, and non-coding RNAs. Experimental evidence suggests that modulators or inhibitors of aerobic glycolysis promote therapeutic effects in preclinical tumor models. Nevertheless, successful clinical translation of drugs that target aerobic glycolysis in PDAC is an obstacle. Moreover, it is necessary to identify the potential targets for future interventions from regulatory networks to design efficacious and safer agents.

RPL35 promotes neuroblastoma progression via the enhanced aerobic glycolysis

Neuroblastoma (NB) is an rare type of tumor that almost affects children age 5 or younger due to its rapid proliferation ability. The overall survival rate of patients with advanced NB is not satisfactory. Ribosomal proteins (RPs) play a critical role in the development and progress of cancer. However, the contribution of RPL35 in NB has not been proven. In this study, we reveal that RPL35 is upregulated in NB tissues and the upregulation of RPL35 promotes proliferation and migration of NB while RPL35 knockdown significantly restrained the proliferation of NB cells. In terms of mechanism, glycolysis was decreased and the mitochondrial respiration was increased with knockdown of RPL35 in NB cells, indicating that RPL35 function as a positive regulator in aerobic glycolysis. Importantly, our data indicated that RPL35 deficiency decreased HIF1α expression both in mRNA and protein levels. Western blot analysis showed that RPL35 knockdown has a negative regulatory effect on the ERK pathway, and RPL35 modulated aerobic glycolysis in part through its regulation of the RPL35/ERK/HIF1α axis. Overall, RPL35 functions as a positive regulator of aerobic glycolysis, and the RPL35/ERK/HIF1α axis could be a potential therapeutic target for the therapy of NB.

Activation of FXR Suppresses Esophageal Squamous Cell Carcinoma Through Antagonizing ERK1/2 Signaling Pathway

Introduction

Farnesoid X receptor (FXR), a member of nuclear receptors, functionally regulates bile acid, glucose and lipid homeostasis. It is also worth noting that FXR plays a suppressor role in cancer and inflammation. However, the contribution of FXR to esophageal squamous cell carcinoma (ESCC) remains unknown.

Methods

The role of FXR activation in ESCC progression was evaluated in ESCC cell lines KYSE150 and EC109 in vitro and BALB-C nude mice in vivo. In vitro, FXR synthetic ligand GW4064 was used to detect the effects on ESCC cell proliferation, migration, apoptosis and cell cycles. To assess the effects of GW4064 on ESCC development in vivo, a xenograft tumor model was constructed. And ERK1/2 activity was evaluated by immunoblot analysis.

Results

FXR synthetic ligand GW4064 impaired esophageal squamous cell carcinoma (ESCC) proliferation and migration, induced apoptosis and cell cycle arrest in vitro, accompanied by inhibition of some inflammatory genes and promotion of pro-apoptotic genes. We then found that FXR activation decreased the phosphorylation levels of ERK1/2 induced by tumor necrosis factor-α (TNF-α) in ESCC cells. Consistent with these results, GW4064 suppressed ESCC tumorigenesis in a xenograft model and suppressed the phosphorylation of ERK1/2 in tumors.

Discussion

These findings identify that activating FXR may serve as a promising therapy or adjuvant therapeutic tool for controlling ESCC development.

Cardiac metallothionein overexpression rescues diabetic cardiomyopathy in Akt2-knockout mice

To efficiently prevent diabetic cardiomyopathy (DCM), we have explored and confirmed that metallothionein (MT) prevents DCM by attenuating oxidative stress, and increasing expression of proteins associated with glucose metabolism. To determine whether Akt2 expression is critical to MT prevention of DCM, mice with either global Akt2 gene deletion (Akt2-KO), or cardiomyocyte-specific overexpressing MT gene (MT-TG) or both combined (MT-TG/Akt2-KO) were used. Akt2-KO mice exhibited symptoms of DCM (cardiac remodelling and dysfunction), and reduced expression of glycogen and glucose metabolism-related proteins, despite an increase in total Akt (t-Akt) phosphorylation. Cardiac MT overexpression in MT-TG/Akt2-KO mice prevented DCM and restored glucose metabolism-related proteins expression and baseline t-Akt phosphorylation. Furthermore, phosphorylation of ERK1/2 increased in the heart of MT-TG/Akt2-KO mice, compared with Akt2-KO mice. As ERK1/2 has been implicated in the regulation of glucose transport and metabolism this increase could potentially underlie MT protective effect in MT-TG/Akt2-KO mice. Therefore, these results show that although our previous work has shown that MT preserving Akt2 activity is sufficient to prevent DCM, in the absence of Akt2 MT may stimulate alternative or downstream pathways protecting from DCM in a type 2 model of diabetes, and that this protection may be associated with the ERK activation pathway.

Highly selective inhibitors of protein kinases CLK and HIPK with the furo[3,2-b]pyridine core

The furo [3,2-b]pyridine motif represents a relatively underexplored central pharmacophore in the area of kinase inhibitors. Herein, we report flexible synthesis of 3,5-disubstituted furo [3,2-b]pyridines that relies on chemoselective couplings of newly prepared 5-chloro-3-iodofuro [3,2-b]pyridine. This methodology allowed efficient second-generation synthesis of the state-of-the-art chemical biology probe for CLK1/2/4 MU1210, and identification of the highly selective inhibitors of HIPKs MU135 and MU1787 which are presented and characterized in this study, including the X-ray crystal structure of MU135 in HIPK2. chemical biology probe.

Identification of HIPK3 as a potential biomarker and an inhibitor of clear cell renal cell carcinoma

Invasion and metastasis are the main causes of poor prognosis in patients with clear cell renal cell carcinoma (ccRCC). The homeodomain interacting protein kinases (HIPKs) can regulate cell proliferation and apoptosis. Little is known about the prognostic role of HIPKs in ccRCC. Here we use Kaplan-Meier survival analysis and multivariate analysis to analyze the correlation of overall survival (OS) and disease–free survival (DFS). ROC curves analyzed the relationship between clinicopathological parameters and HIPK3 expression in ccRCC. Univariate analysis and multivariate analysis confirmed that the expression of HIPK3 was associated with OS (HR, 0.701; P=0.041) and DFS (HR, 0.630; P=0.012). Low HIPK3 expression was a poor prognostic factor and HIPK3 expression was significantly down-regulated in ccRCC cancer tissues when compared with normal renal tissues. In vitro cell results also confirmed that HIPK3 over-expression could inhibit tumor growth and malignant characteristics. The results indicate that low expression of HIPK3 in ccRCC tissues is significantly associated with poor survival rates in tumor patients, and HIPK3 may be used as a valuable biomarker and inhibitor of ccRCC.

Chlorogenic acid depresses cellular bioenergetics to suppress pancreatic carcinoma through modulating c-Myc-TFR1 axis

Pancreatic ductal adenocarcinoma (PDAC) is severe malignant tumor in human, the outcomes of PDAC is extremely poor. Here, we evaluated the potential anti-tumor activity of chlorogenic Acid (CA) in PDAC. Here, we found CA was effective to suppress PDAC cell growth in vitro and in vivo. Importantly, we found overall oxygen consumption rate was significantly decreased in CA dose-dependent manner. We also found glycolysis reverse was decreased in CA-treated cells, while basal glycolysis and glycolytic capacity were not significantly changed. Mechanistically, we demonstrated TFR1 could be a novel downstream target of CA, which is essential for PDAC cell growth and cellular bioenergetics maintenance. Furthermore, we validated that CA-reduced c-Myc resulted to down-regulation of TFR1, which contributes to mitochondrial respiration dysfunction and cell growth delay. Together, this study indicates that CA suppresses PDAC cell growth through targeting c-Myc-TFR1 axis and suggests CA could be considered as a promising compound for PDAC treatment.

Epigenetic silencing of LncRNA LINC00261 promotes c-myc-mediated aerobic glycolysis by regulating miR-222-3p/HIPK2/ERK axis and sequestering IGF2BP1

Long noncoding RNAs have been identified as key regulators in the progression of various cancers. LINC00261 has been reported as a tumor suppressor in multiple cancers. However, its function and underlying mechanisms in pancreatic cancer remain largely unclear. Quantitative real-time PCR was performed to detect RNA expression. In situ hybridization was used to discover the subcellular location. The direct binding of LINC00261 to miR-222-3p was verified using a dual-luciferase reporter assay and RNA immunoprecipitation. LINC00261-binding proteins were detected using an RNA pulldown assay. LINC00261 was downregulated in pancreatic cancer tissues and cell lines. Its reduced expression was correlated with advanced pathological stage and poor prognosis. Forced expression of LINC00261 suppressed pancreatic cancer glycolysis and proliferation and induced cell cycle arrest and apoptosis. Mechanistically, downregulation of LINC00261 was caused by hypermethylation of the CpG island in the promoter region and EZH2-mediated histone H3 lysine 27 trimethylation. Moreover, LINC00261 exerted its biological function by binding to miR-222-3p to activate the HIPK2/ERK/c-myc pathway. In addition, LINC00261 could also reduce c-myc expression by sequestering IGF2BP1. Our study suggests that LINC00261 functions as a tumor suppressor in pancreatic cancer and identifies novel epigenetic and posttranscriptional regulatory mechanisms of LINC00261, which contribute to the targeted therapy of pancreatic cancer.

Four genes predict the survival of osteosarcoma patients based on TARGET database

Osteosarcoma represents one of the most aggressive tumors of bone among adolescents and young adults. Despite improvements in treatment, osteosarcoma has a grave prognosis. The identification of prognostic factors is still in its infancy. Weighted gene correlation network analysis (WGCNA) was conducted on mRNA-sequencing and clinical information (gender, survival and metastasis) of osteosarcoma patients from the TARGET database to obtain genes in modules associated with metastasis of osteosarcoma. The Cox regression analysis was then performed on the gene expression profile from TARGET to screen genes associated with patients' survival. Known genes related to osteosarcoma were obtained by intersecting osteosarcoma-related genes from DisGeNET and DiGSeE, followed by the construction of PPI network of osteosarcoma-related genes and survival-related genes in modules. The screened key genes were subject to multi-factor Cox proportional hazards model, and osteosarcoma patients were classified into high- and low- risk groups according to the risk score to evaluate the potential of key genes to predict the survival of osteosarcoma patients. The WGCNA showed that 4 genes in tan and 19 genes in pink modules were related to the survival of osteosarcoma patients. Osteosarcoma-related known genes (9) were obtained in intersection of DisGeNET and DiGSeE. PPI network identified 4 key genes (KRT5, HIPK2, MAP3K5 and CD5) closely associated with survival of osteosarcoma patients. HIPK2, MAP3K5 and CD5 expression was inversely correlated with survival risk, while KRT5 expression was positively correlated with survival risk. These results show KRT5, HIPK2, MAP3K5 and CD5 serve as prognostic factors of osteosarcoma patients.

HBXIP Regulates Gastric Cancer Glucose Metabolism and Malignancy Through PI3K/AKT and p53 Signaling

Introduction

Hepatitis B X-interacting protein (HBXIP) overexpression is related to the progression of multiple cancers. However, its role in gastric cancer (GC) remains unclear.

Materials and Methods

HBXIP expression was determined in human GC specimens and cell lines by quantitative polymerase chain reaction (qRT-PCR) and Western blot. The effects of HBXIP depletion or ectopic expression on GC proliferation were evaluated in vitro using the cell counting kit-8 (CCK-8), 5-ethynyl-2ʹ-deoxyuridine (EdU) incorporation, colony formation, and cell cycle assays. The in vivo effects were investigated using a mouse xenograft model. Apoptosis was evaluated by flow cytometry (in vitro) and immunohistochemistry (IHC; in vivo). Cell migration and invasion were evaluated in vitro using wound healing, transwell migration, and matrigel invasion assays; and in vivo by quantifying distant metastases from injection of GC cells in the lateral tail vein.

Results

Herein, we reported that HBXIP expression was higher in GC than in normal tissues, and this high expression indicated a poorer prognosis. Gain- and loss-of-function assays showed that HBXIP promoted GC proliferation, migration, and invasion, and inhibited apoptosis. High-performance liquid chromatography (HPLC) quantification of glycolytic metabolites revealed that HBXIP promoted glucose metabolic reprogramming. Investigation of the PI3K/AKT and p53 pathways highlighted their role in this HBXIP-mediated metabolic reprogramming.

Conclusion

Our results indicate that the up-regulation of HBXIP leads to GC progression by positively regulating glucose metabolism. Therefore, HBXIP is a potential target for the treatment of GC.

An Alternative Splice Variant of HIPK2 with Intron Retention Contributes to Cytokinesis

HIPK2 is a DYRK-like kinase involved in cellular stress response pathways, development, and cell division. Two alternative splice variants of HIPK2, HIPK2-FL and HIPK2-Δe8, have been previously identified as having different protein stability but similar functional activity in the stress response. Here, we describe one additional HIPK2 splice variant with a distinct subcellular distribution and functional activity in cytokinesis. This novel splice variant lacks the last two exons and retains intron13 with a stop codon after 89 bp of the intron, generating a short isoform, HIPK2-S, that is detectable by 2D Western blots. RT-PCR analyses of tissue arrays and tumor samples show that HIPK2-FL and HIPK2-S are expressed in normal human tissues in a tissue-dependent manner and differentially expressed in human colorectal and pancreatic cancers. Gain- and loss-of-function experiments showed that in contrast to HIPK2-FL, HIPK2-S has a diffuse, non-speckled distribution and is not involved in the DNA damage response. Rather, we found that HIPK2-S, but not HIPK2-FL, localizes at the intercellular bridge, where it phosphorylates histone H2B and spastin, both required for faithful cell division. Altogether, these data show that distinct human HIPK2 splice variants are involved in distinct HIPK2-regulated functions like stress response and cytokinesis.

HIPK2 suppresses tumor growth and progression of hepatocellular carcinoma through promoting the degradation of HIF-1α

Aberrant angiogenesis of hepatocellular carcinoma (HCC) leads to tumor growth and local or distant metastasis. Uncovering the underlying mechanisms for the neoangiogenesis of HCC can provide novel potential therapeutic targets in the clinic. Here, we reported that serine/threonine homeodomain-interacting protein kinase 2 (HIPK2) was frequently downregulated in HCC tissues compared with the adjacent normal tissues, and patients with lower HIPK2 protein expression were associated with worse overall survival. Both in vitro and in vivo, HIPK2 inhibited the migration of HCC cells, as well as tumor growth and metastasis in xenograft and orthotopic syngeneic HCC mouse models. Furthermore, HIPK2 inhibited the angiogenesis in HCC tumors. Under the hypoxic condition, HIPK2 knockdown enhanced the angiogenesis and the key regulator, HIF-1α signaling pathway; however, HIPK2 overexpression downregulated the tumoral angiogenesis and HIF-1α signaling. In HCC cells, HIPK2 could directly bind to HIF-1α and stimulate the ubiquitination of HIF-1α for proteasomal degradation. HIF-1α knockout partially rescued the promoting effect of HIPK2 depletion on angiogenesis and tumor growth. In conclusion, the downregulation of HIPK2 could enhance the angiogenesis in HCC through inducing the HIF-1α pathway, and further contribute to tumor growth and metastasis, which may provide a novel therapeutic strategy for HCC.

Nuclear FAM289-Galectin-1 interaction controls FAM289-mediated tumor promotion in malignant glioma

Background

FAM92A1–289(abbreviated FAM289) is recognized as one of the newly-discovered putative oncogenes. However, its role and molecular mechanisms in promoting cancer progression has not yet been elucidated. This study was performed to reveal its oncogenic functions and molecular mechanisms in human glioblastoma multiforme (GBM) cell models with knockdown or overexpression of FAM289 in vitro and in vivo.

Methods

To elucidate the molecular mechanisms underlying FAM289-mediated tumor progression, the protein-protein interaction between FAM289 and Galectin-1 was verified by co-immunoprecipitation, followed by an analysis of the expression and activity of Galectin-1-associated signaling molecules. Knockdown and overexpression of FAM289 in glioma cells were applied for investigating the effects of FAM289 on cell growth, migration and invasion. The determination of FAM289 expression was performed in specimens from various stages of human gliomas.

Results

FAM289-galectin-1 interaction and concomitant activation of the extracellular signal-regulated kinase (ERK) pathway participated in FAM289-mediated tumor-promoting function. Since the expression of DNA methyl transferase 1 (DNMT1) and DNA methyl transferase 3B (DNMT3B) was regulated by FAM289 in U251 and U87-MG glioma cells, Galectin-1 interaction with FAM289 may promote FAM289 protein into the cell nucleus and activate the ERK pathway, thereby upregulating DNMTs expression. Drug resistance tests indicated that FAM289-mediated TMZ resistance was through stem-like property acquisition by activating the ERK pathway. The correlation between FAM289, Galectin-1 expression and the clinical stage of gliomas was also verified in tissue samples from glioblastoma patients.

Conclusions

Our results suggest that high expression of FAM289 in GBM tissues correlated with poor prognosis. FAM289 contributes to tumor progression in malignant glioma by interacting with Galectin-1 thereby promoting FAM289 protein translocation into the cell nucleus. FAM289 in the nucleus activated the ERK pathway, up regulated DNMTs expression and induced stem-like property gene expression which affects drug resistance of glioma cells to TMZ. This study provided functional evidence for FAM289 to be developed as a therapeutic target for cancer treatment.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1393-7) contains supplementary material, which is available to authorized users.

Homeodomain-interacting protein kinase 2 suppresses proliferation and aerobic glycolysis via ERK/cMyc axis in pancreatic cancer

OBJECTIVES

To investigate the roles of the homeodomain-interacting protein kinase (HIPK) family of proteins in pancreatic cancer prognosis and the possible molecular mechanism.

MATERIALS AND METHODS

The expression of HIPK family genes and their roles in pancreatic cancer prognosis were analysed by using The Cancer Genome Atlas (TCGA). The roles of HIPK2 in pancreatic cancer proliferation and glycolysis were tested by overexpression of HIPK2 in pancreatic cancer cells, followed by cell proliferation assay, glucose uptake analysis and Seahorse extracellular flux analysis. The mechanism of action of HIPK2 in pancreatic cancer proliferation and glycolysis was explored by examining its effect on the ERK/cMyc axis.

RESULTS

Decreased HIPK2 expression indicated worse prognosis of pancreatic cancer. Overexpression of HIPK2 in pancreatic cancer cells decreased cell proliferation and attenuated aerobic glycolysis, which sustained proliferation of cancer cells. HIPK2 decreased cMyc protein levels and expression of cMyc-targeted glycolytic genes. cMyc was a mediator that regulated HIPK2-induced decrease in aerobic glycolysis. HIPK2 regulated cMyc protein stability via ERK activation, which phosphorylated and controlled cMyc protein stability.

CONCLUSIONS

HIPK2 suppressed proliferation of pancreatic cancer in part through inhibiting the ERK/cMyc axis and related aerobic glycolysis.