Pim-3 promotes human pancreatic cancer growth by regulating tumor vasculogenesis

PIM3 Kinase: A Promising Novel Target in Solid Cancers

PIM3 (provirus-integrating Moloney site 3) is a serine/threonine kinase and belongs to the PIM family (PIM1, PIM2, and PIM3). PIM3 is a proto-oncogene that is frequently overexpressed in cancers originating from endoderm-derived tissues, such as the liver, pancreas, colon, stomach, prostate, and breast cancer. PIM3 plays a critical role in activating multiple oncogenic signaling pathways promoting cancer cell proliferation, survival, invasion, tumor growth, metastasis, and progression, as well as chemo- and radiation therapy resistance and immunosuppressive microenvironment. Genetic inhibition of PIM3 expression suppresses in vitro cell proliferation and in vivo tumor growth and metastasis in mice with solid cancers, indicating that PIM3 is a potential therapeutic target. Although several pan-PIM inhibitors entered phase I clinical trials in hematological cancers, there are currently no FDA-approved inhibitors for the treatment of patients. This review provides an overview of recent developments and insights into the role of PIM3 in various cancers and its potential as a novel molecular target for cancer therapy. We also discuss the current status of PIM-targeted therapies in clinical trials.

Comprehensive Insights that Targeting PIM for Cancer Therapy: Prospects and Obstacles

Proviral integration sitea for Moloney-murine leukemia virus (PIM) kinases are a family of highly conserved serine/tyrosine kinases consisting of three members, PIM-1, PIM-2, and PIM-3. These kinases regulate a wide range of substrates through phosphorylation and affect key cellular processes such as transcription, translation, proliferation, apoptosis, and energy metabolism. Several PIM inhibitors are currently undergoing clinical trials, such as a phase I clinical trial of Uzanserti (5) for the treatment of relapsed diffuse large B-cell lymphoma that has been completed. The current focus encompasses the structural and biological characterization of PIM, ongoing research progress on small-molecule inhibitors undergoing clinical trials, and evaluation analysis of persisting challenges in this field. Additionally, the design and discovery of small-molecule inhibitors targeting PIM in recent years have been explored, with a particular emphasis on medicinal chemistry, aiming to provide valuable insights for the future development of PIM inhibitors.

PIM3 kinase promotes tumor metastasis in hepatoblastoma by upregulating cell surface expression of chemokine receptor cxcr4

Patients presenting with metastatic hepatoblastoma have limited treatment options and survival rates as low as 25%. We previously demonstrated that Proviral Integration site in Maloney murine leukemia virus 3 (PIM3) kinase promotes tumorigenesis and cancer cell stemness in hepatoblastoma. In this study, we assessed the role of PIM3 kinase in promoting hepatoblastoma metastasis. We utilized a tail vein injection model of metastasis to evaluate the effect of CRISPR/Cas9-mediated PIM3 knockout, stable overexpression of PIM3, and pharmacologic PIM inhibition on the formation of lung metastasis. In vivo studies revealed PIM3 knockout impaired the formation of lung metastasis: 5 out of 6 mice injected with wild type hepatoblastoma cells developed lung metastasis while none of the 7 mice injected with PIM3 knockout hepatoblastoma cells developed lung metastasis. PIM3 overexpression in hepatoblastoma increased the pulmonary metastatic burden in mice and mechanistically, upregulated the phosphorylation and cell surface expression of CXCR4, a key receptor in the progression of cancer cell metastasis. CXCR4 blockade with AMD3100 decreased the metastatic phenotype of PIM3 overexpressing cells, indicating that CXCR4 contributed to PIM3's promotion of hepatoblastoma metastasis. Clinically, PIM3 expression correlated positively with CXCR4 expression in primary hepatoblastoma tissues. In conclusion, we have shown PIM3 kinase promotes the metastatic phenotype of hepatoblastoma cells through upregulation of CXCR4 cell surface expression and these findings suggest that targeting PIM3 kinase may provide a novel therapeutic strategy for metastatic hepatoblastoma.

CRISPR/Cas9-mediated knockout of PIM3 suppresses tumorigenesis and cancer cell stemness in human hepatoblastoma cells

Hepatoblastoma remains one of the most difficult childhood tumors to treat and is alarmingly understudied. We previously demonstrated that Proviral Insertion site in Maloney murine leukemia virus (PIM) kinases, specifically PIM3, are overexpressed in human hepatoblastoma cells and function to promote tumorigenesis. We aimed to use CRISPR/Cas9 gene editing with dual gRNAs to introduce large inactivating deletions in the PIM3 gene and achieve stable PIM3 knockout in the human hepatoblastoma cell line, HuH6. PIM3 knockout of hepatoblastoma cells led to significantly decreased proliferation, viability, and motility, inhibited cell-cycle progression, decreased tumor growth in a xenograft murine model, and increased animal survival. Analysis of RNA sequencing data revealed that PIM3 knockout downregulated expression of pro-migratory and pro-invasive genes and upregulated expression of genes involved in apoptosis and differentiation. Furthermore, PIM3 knockout decreased hepatoblastoma cancer cell stemness as evidenced by decreased tumorsphere formation, decreased mRNA abundance of stemness markers, and decreased cell surface expression of CD133, a marker of hepatoblastoma stem cell-like cancer cells. Reintroduction of PIM3 into PIM3 knockout cells rescued the malignant phenotype. Successful CRISPR/Cas9 knockout of PIM3 kinase in human hepatoblastoma cells confirmed the role of PIM3 in promoting hepatoblastoma tumorigenesis and cancer cell stemness.

Fibroblast growth factor 8 overexpression is predictive of poor prognosis in pancreatic ductal adenocarcinoma

Background

Despite distinctive advances in the field of pancreatic cancer therapy over the past few years, patient survival remains poor. Fibroblast growth factors 8 (FGF8) and 18 (FGF18) both play a role in modulating the activity of malignant cells and have been identified as promising biomarkers in a number of cancers. However, no data exist on the expression of FGF8 and FGF18 in pancreatic ductal adenocarcinoma (PDAC).

Methods

Protein expression levels of FGF8 and FGF18 in postoperative specimens of neoadjuvantly treated and primarily resected patients were investigated using immunohistochemistry. Immunostaining scores were calculated as the products of the staining intensity and the staining rate. Scores exceeding the median score were considered as high expression.

Results

Specimens from 78 patients with PDAC were available and met the eligibility criteria for analysis of protein expression using immunohistochemistry. 15 (19.2%) patients had received neoadjuvant chemotherapy. High protein levels of FGF8 and FGF18 were detected in 40 (51.8%) and 33 (42.3%) patients, respectively. Kaplan–Meier analysis demonstrated significantly shorter overall survival in patients with high expression of FGF8 (p = 0.04). Multivariable Cox proportional hazard regression models revealed that high expression of FGF8 (Hazard ratio [HR] 0.53, 95% Confidence interval [CI] 0.32–0.89, p = 0.016) was an independent prognostic factor for diminished overall survival in patients with PDAC. By contrast, no statistical significance was found for FGF18 overexpression. In addition, the FGF8 protein level correlated with the factor resection margin (p = 0.042).

Conclusion

FGF8 is a promising target for new anticancer therapies using FGF inhibitors in pancreatic ductal adenocarcinomas.

An approach using Caenorhabditis elegans screening novel targets to suppress tumour cell proliferation

OBJECTIVES

Tumour cell proliferation requires high metabolism to meet the bioenergetics and biosynthetic needs. Dauer in Caenorhabditis elegans is characterized by lower metabolism, and we established an approach with C elegans to find potential tumour therapy targets.

MATERIALS AND METHODS

RNAi screening was used to find dauer-related genes, and these genes were further analysed in glp-1(-) mutants for tumour-suppressing testing. The identified tumour-related genes were verified in clinical tumour tissues.

RESULTS

The lifespan of glp-1(-) mutants was found to be extended by classical dauer formation signalling. Then, 61 of 287 kinase-coding genes in Caenorhabditis elegans were identified as dauer-related genes, of which 27 were found to be homologous to human oncogenes. Furthermore, 12 dauer-related genes were randomly selected for tumour-suppressing test, and six genes significantly extended the lifespan of glp-1(-) mutants. Of these six genes, F47D12.9, W02B12.12 and gcy-21 were newly linked to dauer formation. These three new dauer-related genes significantly suppressed tumour cell proliferation and thus extended the lifespan of glp-1(-) mutants in a longevity- or dauer-independent manner. The mRNA expression profiles indicated that these dauer-related genes trigged similar low metabolism pattern in glp-1(-) mutants. Notably, the expression of homolog gene DCAF4L2/F47D12.9, TSSK6/W02B12.12 and NPR1/gcy-21 was found to be higher in glioma compared with adjacent normal tissue. In addition, the high expression of TSSK6/W02B12.12 and NPR1/gcy-21 correlated with a worse survival in glioma patients.

CONCLUSIONS

Dauer gene screening in combination with tumour-suppressing test in glp-1(-) mutants provided a useful approach to find potential targets for tumour therapy via suppressing tumour cell proliferation and rewiring tumour cell metabolism.

Bufothionine exerts anti-cancer activities in gastric cancer through Pim3

AIM

Gastric cancer (GC) is the fourth most common cancer globally. Bufothionine is a major active constituent of Cinobufacini (Huachansu), which is extracted from the skin and parotid venom gland of the toad Bufo bufo gargarizans Cantor. It exhibits anti-cancer activities in vitro. However, whether bufothionine exerts anti-cancer activities against GC is unknown. This study was designed to evaluate the efficacy of bufothionine in vitro and in vivo.

MATERIAL AND METHODS

MKN28 and AGS cells were chosen as cell models to study the anti-cancer effect of bufothionine. Cell viability was determined by CCK-8 assay, while the effect of bufothionine on cell membrane integrity was examined by LDH assay. Cell apoptosis was detected by Hoechst/PI staining and Annexin V-FITC/PI staining followed by flow cytometry analysis. The expression levels of proteins involved were examined using western blotting. I-Traq analysis was conducted to identify the differentially expressed genes in AGS cells following bufothionine treatment. The anti-growth effect of bufothionine was validated in vivo using a GC xenograft model.

KEY FINDINGS

The results revealed that bufothionine prevented the growth, destroyed cell membrane and promoted apoptotic cell death of GC cells. iTRAQ analysis revealed thatPIM3 might be a molecular target responsible for the anti-cancer effects of bufothionine. It was also found that PIM3 knockdown significantly augmented the anti-growth and pro-apoptotic effects of bufothionine in GC cells. In contrast, ectopic PIM3 expression markedly dampened the anti-neoplastic activities of bufothionine. The expression of PIM3 was also suppressed by bufothionine treatment in xenograft tumor tissue.

SIGNIFICANCE

Bufothionine exhibited anti-cancer activities in vitro and in vivo in GC via downregulating PIM3.

Deciphering role of FGFR signalling pathway in pancreatic cancer

Recently, fibroblast growth factors are identified to play a vital role in the development and progression of human pancreatic cancer. FGF pathway is critical involved in numerous cellular processes through regulation of its downstream targets, including proliferation, apoptosis, migration, invasion, angiogenesis and metastasis. In this review article, we describe recent advances of FGFR signalling pathway in pancreatic carcinogenesis and progression. Moreover, we highlight the available chemical inhibitors of FGFR pathway for potential treatment of pancreatic cancer. Furthermore, we discuss whether targeting FGFR pathway is a novel therapeutic strategy for pancreatic cancer clinical management.

Pim-3 enhances melanoma cell migration and invasion by promoting STAT3 phosphorylation

Melanoma is the deadliest form of commonly encountered skin cancer, and has fast propagating and highly invasive characteristics. Pim-3, a highly expressed oncogene in melanoma, is a highly conserved serine/threonine kinase with various biological activities, such as proliferation-accelerating and anti-apoptosis effects on cancer progression. However, whether Pim-3 regulates melanoma metastasis has not been determined. Here, we constructed a Pim-3-silencing short hairpin RNA (sh-Pim-3), a TLR7-stimulating ssRNA and a dual-function vector containing a sh-Pim-3 and a ssRNA, and transfected them into the B16F10 melanoma cell line to investigate the effects of Pim-3 on migration and invasion in melanoma. We found that sh-Pim-3 inhibited B16F10 cell migration and invasion in vitro. In a tumor-bearing mouse model, sh-Pim-3 significantly downregulated pulmonary metastasis of B16F10 melanoma cell in vivo. Mechanistically, sh-Pim-3 inhibited metastasis by regulating the expression of genes related to epithelial-mesenchymal transition (EMT). Further study revealed that by promoting the phosphorylation of STAT3 (signal transducer and activator of transcription 3), Pim-3 induced the expression of Slug, Snail, and ZEB1, which enhanced EMT-related changes and induced melanoma migration and invasion. Our study suggests that Pim-3 is a potential effective target for melanoma therapy.

Genomic Variations in Pancreatic Cancer and Potential Opportunities for Development of New Approaches for Diagnosis and Treatment

Human pancreatic cancer has a very poor prognosis with an overall five-year survival rate of less than 5% and an average median survival time of six months. This is largely due to metastatic disease, which is already present in the majority of patients when diagnosed. Although our understanding of the molecular events underlying multi-step carcinogenesis in pancreatic cancer has steadily increased, translation into more effective therapeutic approaches has been inefficient in recent decades. Therefore, it is imperative that novel and targeted approaches are designed to facilitate the early detection and treatment of pancreatic cancer. Presently, there are numerous ongoing studies investigating the types of genomic variations in pancreatic cancer and their impact on tumor initiation and growth, as well as prognosis. This has led to the development of therapeutics to target these genetic variations for clinical benefit. Thus far, there have been minimal clinical successes directly targeting these genomic alterations; however research is ongoing to ultimately discover an innovative approach to tackle this devastating disease. This review will discuss the genomic variations in pancreatic cancer, and the resulting potential diagnostic and therapeutic implications.

Pim-3 is a Critical Risk Factor in Development and Prognosis of Prostate Cancer

BACKGROUND Pim-3 kinase is a highly homologous serine/threonine kinase that is overexpressed in hematological malignancies and solid tumors. Few studies have been conducted to define the role of Pim-3 in solid tumors, especially in prostate cancer. The aim of this study was to define the role of Pim-3 in development and prognosis of prostate cancer. MATERIAL AND METHODS We collected specimens from 160 patients with prostate cancer, as well as 100 patients with benign prostatic hyperplasia. Realtime polymerase chain reaction was used for the assessment of Pim-3 expression at the RNA level and Western blot was used to quantify the Pim-3 protein synthesis in 3 different cell lines. RESULTS We found that Pim-3 mRNA expression in prostate cancer tissue was significantly higher than that in benign prostatic hyperplasia tissue (p<0.05). Accordingly, the protein level expression of Pim-3 in prostate cancer cell lines was also significantly higher than that in control cells. In addition, the expression status of Pim-3 mRNA was significantly associated with pathological parameters such as pre-surgery prostate specific antigen, Gleason score, pathological stage, and lymphoid metastasis. High expression of Pim-3 also significantly decreased the survival rate of patients after surgery. CONCLUSIONS Pim-3 expression is an important risk factor for prostate cancer; we are the first team to report Pim-3 as a valuable biomarker in Chinese.

MiR-377 inhibits the proliferation of pancreatic cancer by targeting Pim-3

MicroRNAs (miRNAs) play important roles in the regulation of various tumor biological processes including proliferation and apoptosis. MiR-377 has been implicated in many types of cancer, whereas its expressional feature and potential biological function in pancreatic ductal adenocarcinoma (PDAC) remains unclear. In this study, we scanned the global miRNA expression profiles in PDAC from The Cancer Genome Atlas (TCGA) and found miR-377 was down-regulated significantly in PDAC. Then, its expression was measured in both pancreatic cancer tissues and cells; the data showed that miR-377 was de-regulated and inversely correlated with pathologic parameters of tumor growth or metastasis. We generated PDAC cell lines with stable overexpression or inhibition of miR-377, and our results indicated that miR-377 up-regulation significantly promoted cell viability, proliferation, and migration in PDAC cells, and also induced cell apoptosis and cell cycle arrest simultaneously. Binding-site predictions by bioinformatics showed that Pim-3 might be a potential target of miR-377. Luciferase reporter assay ulteriorly identified that miR-377 suppressed Pim-3 expression by binding the 3'-UTR. In tumor tissues, we also showed that the Pim-3 expression was inversely correlated with that of miR-377. Furthermore, stable ectopic miR-377 expression in pancreatic cancer cell lines suppressed Pim-3 expression, leading to the attenuation of Bad phosphorylation level at its Ser112 and promoting cell apoptosis. Overall, these results reveal that miR-377 may have tumor growth suppression function by down-regulating Pim-3 kinase expression to inhibit both pancreatic tumor growth and migration, and induce cell apoptosis. Hence, miR-377 may be a potential diagnostic marker and therapeutic target.

PIM-1 contributes to the malignancy of pancreatic cancer and displays diagnostic and prognostic value

Background

The effects of PIM-1 on the progression of pancreatic cancer remain unclear, and the prognostic value of PIM-1 levels in tissues is controversial. Additionally, the expression levels and clinical value of PIM-1 in plasma have not been reported.

Methods

The effects of PIM-1 on biological behaviours were analysed. PIM-1 levels in tissues and plasma were detected, and the clinical value was evaluated.

Results

We found that PIM-1 knockdown in pancreatic cancer cells suppressed proliferation, induced cell cycle arrest, enhanced apoptosis, resensitized cells to gemcitabine and erlotinib treatment, and inhibited ABCG2 and EZH2 mRNA expression. Our results indicated that PIM-1 and the EGFR pathway formed a positive feedback loop. We also found that PIM-1 expression in pancreatic cancer tissues was significantly upregulated and that a high level of expression was negatively associated with prognosis (P = 0.025, hazard ratio [HR] =2.113, 95 % confidence interval: 1.046–4.266). Additionally, we found that plasma PIM-1 levels in patients with pancreatic cancer were significantly increased and could be used in the diagnosis of pancreatic cancer. High plasma PIM-1 expression was an independent adverse prognostic factor for pancreatic cancer (P = 0.037, HR = 1.87, 95 % CI: 1.04–3.35).

Conclusion

Our study suggests that PIM-1 contributes to malignancy and has diagnostic and prognostic value in pancreatic cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0406-z) contains supplementary material, which is available to authorized users.

Concise Review: Pancreatic Cancer and Bone Marrow-Derived Stem Cells

Pancreatic adenocarcinoma remains one of the most challenging diseases of modern gastroenterology, and, even though considerable effort has been put into understanding its pathogenesis, the exact molecular mechanisms underlying the development and/or systemic progression of this malignancy still remain unclear. Recently, much attention has been paid to the potential role of bone marrow-derived stem cells (BMSCs) in this malignancy. Hence, herein, we comprehensively review the most recent discoveries and current achievements and concepts in this field. Specifically, we discuss the significance of identifying pancreatic cancer stem cells and novel therapeutic approaches involving molecular interference of their metabolism. We also describe advances in the current understanding of the biochemical and molecular mechanisms responsible for BMSC mobilization during pancreatic cancer development and systemic spread. Finally, we summarize experimental, translational, and/or clinical evidence regarding the contribution of bone marrow-derived mesenchymal stem cells, endothelial progenitor cells, hematopoietic stem/progenitor cells, and pancreatic stellate cells in pancreatic cancer development/progression. We also present their potential therapeutic value for the treatment of this deadly malignancy in humans.

SIGNIFICANCE

Different bone marrow-derived stem cell populations contribute to the development and/or progression of pancreatic cancer, and they might also be a promising "weapon" that can be used for anticancer treatments in humans. Even though the exact role of these stem cells in pancreatic cancer development and/or progression in humans still remains unclear, this concept continues to drive a completely novel scientific avenue in pancreatic cancer research and gives rise to innovative ideas regarding novel therapeutic modalities that can be safely offered to patients.

Comprehensive assembly of novel transcripts from unmapped human RNA-Seq data and their association with cancer

Crucial parts of the genome including genes encoding microRNAs and noncoding RNAs went unnoticed for years, and even now, despite extensive annotation and assembly of the human genome, RNA-sequencing continues to yield millions of unmappable and thus uncharacterized reads. Here, we examined > 300 billion reads from 536 normal donors and 1,873 patients encompassing 21 cancer types, identified ∼300 million such uncharacterized reads, and using a distinctive approach de novo assembled 2,550 novel human transcripts, which mainly represent long noncoding RNAs. Of these, 230 exhibited relatively specific expression or non-expression in certain cancer types, making them potential markers for those cancers, whereas 183 exhibited tissue specificity. Moreover, we used lentiviral-mediated expression of three selected transcripts that had higher expression in normal than in cancer patients and found that each inhibited the growth of HepG2 cells. Our analysis provides a comprehensive and unbiased resource of unmapped human transcripts and reveals their associations with specific cancers, providing potentially important new genes for therapeutic targeting.

Pancreatic cancer patient survival correlates with DNA methylation of pancreas development genes

DNA methylation is an epigenetic mark associated with regulation of transcription and genome structure. These markers have been investigated in a variety of cancer settings for their utility in differentiating normal tissue from tumor tissue. Here, we examine the direct correlation between DNA methylation and patient survival. We find that changes in the DNA methylation of key pancreatic developmental genes are strongly associated with patient survival.