UM171 suppresses breast cancer progression by inducing KLF2.

PURPOSE: Breast cancer is the most frequent cancer in women with significant death rate. Morbidity is associated with drug resistance and metastasis. Development of novel drugs is unmet need. The aim of this study is to show potent anti-neoplastic activity of the UM171 compound on breast cancer cells and its mechanism of action. METHODS: The inhibitory effect of UM171 on several breast cancer (BC) cell lines was examined using MTT and colony-forming assays. Cell cycle and apoptosis assays were utilized to determine the effect of UM171 on BC cell proliferation and survival. Wound healing scratch and transwell migration assays were used to examine the migration of BC cell lines in culture. Xenograft of mouse model with 4T1 cells was used to determine inhibitory effect of UM171 in vivo. Q-RT-PCR and western blotting were used to determine the expression level of genes effected by UM171. Lentivirus-mediated shRNAs were used to knockdown the expression of KLF2 in BC cells. RESULTS: UM171 was previously identified as a potent agonist of human hematopoietic stem cell renewal and inhibitor of leukemia. In this study, UM171 was shown to inhibit the growth of multiple breast cancer cell lines in culture. UM171-mediated growth inhibition was associated with the induction of apoptosis, G2/M cell cycle arrest, lower colony-forming capacity, and reduced motility. In a xenotransplantation model of mouse triple-negative breast cancer 4T1 cells injected into syngeneic BALB/c mice, UM171 strongly inhibited tumor growth at a level comparable to control paclitaxel. UM171 increased the expression of the three PIM genes (PIM1-3) in breast cancer cells. Moreover, UM171 strongly induced the expression of the tumor suppressor gene KLF2 and cell cycle inhibitor P21CIP1. Accordingly, knockdown of KLF2 using lentivirus-mediated shRNA significantly attenuated the growth suppressor activity of UM171. As PIM1-3 act as oncogenes and are involved in breast cancer progression, induction of these kinases likely impedes the inhibitory effect of KLF2 induction by UM171. Accordingly, combination of UM171 with a PAN-PIM inhibitor LGH447 significantly reduced tumor growth in culture. CONCLUSION: These results suggested that UM171 inhibited breast cancer progression in part through activation of KLF2 and P21. Combination of UM171 with a PAN-PIM inhibitor offer a novel therapy for aggressive forms of breast cancer.

LncRNA SNHG1 Accelerates Cell Proliferation, Migration, and Invasion of Hepatoblastoma Through Mediating miR-6838-5p/PIM3/RhoA Axis.

Hepatoblastoma (HB) is a common primary liver malignant tumor in children. Long non-coding RNAs (lncRNAs) are closely engaged in HB progression. The role and regulatory molecule mechanism of lncRNA small nucleolar RNA host gene 1 (SNHG1) in HB remain unclear. Through qRT-PCR or western blot, we found that SNHG1 and proviral integration site for moloney murine leukemia virus 3 (PIM3) were elevated but miR-6838-5p was decreased in HB cells. Cell biology experiments revealed that SNHG1 depletion or miR-6838-5p upregulation suppressed cell proliferation, migration, and invasion of HB cells. Mechanistically, luciferase activity assay validated that miR-6838-5p could interact with SNHG1 or PIM3. SNHG1 up-regulated PIM3 expression via sponging miR-6838-5p. Moreover, miR-6838-5p inhibitor abolished SNHG1 depletion-mediated suppression of malignant behaviors in HB cells. PIM3 overexpression neutralized miR-6838-5p mimics-mediated repression of malignant phenotypes in HB cells. Furthermore, miR-6838-5p overexpression suppressed RhoA activation, which was restored by PIM3 upregulation. What's more, the results at the cellular level were further verified by nude mice tumor formation experiment. In conclusion, SNHG1 regulated miR-6838-5p/PIM3/RhoA axis to promote malignant phenotypes of HB, which might provide novel therapeutic target for HB treatment.

Targeting Pim kinases in hematological cancers: molecular and clinical review.

Decades of research has recognized a solid role for Pim kinases in lymphoproliferative disorders. Often up-regulated following JAK/STAT and tyrosine kinase receptor signaling, Pim kinases regulate cell proliferation, survival, metabolism, cellular trafficking and signaling. Targeting Pim kinases represents an interesting approach since knock-down of Pim kinases leads to non-fatal phenotypes in vivo suggesting clinical inhibition of Pim may have less side effects. In addition, the ATP binding site offers unique characteristics that can be used for the development of small inhibitors targeting one or all Pim isoforms. This review takes a closer look at Pim kinase expression and involvement in hematopoietic cancers. Current and past clinical trials and in vitro characterization of Pim kinase inhibitors are examined and future directions are discussed. Current studies suggest that Pim kinase inhibition may be most valuable when accompanied by multi-drug targeting therapy.

LncRNA RGMB-AS1 facilitates pancreatic cancer cell proliferation and migration but inhibits cell apoptosis via miR-574-3p/PIM3 axis.

Pancreatic cancer (PC) is among the most notorious malignancies worldwide. Long noncoding RNA (lncRNA) repulsive guidance molecule bone morphogenetic protein (BMP) coreceptor b antisense RNA 1 (RGMB-AS1) was an oncogene in glioma. However, the RGMB-AS1 function in PC remains largely unknown. Herein, quantitative real-time polymerase chain reaction was performed to analyze the expression of RGMB-AS1. We determined RGMB-AS1 influence on PC cell malignant behaviors via functional assays. Besides, we applied subcellular fractionation and fluorescence in situ hybridization (FISH) assays to confirm the cellular distribution of RGMB-AS1 in PC cells. We used mechanism assays to detect the regulatory axis of RGMB-AS1 in PC cells. Briefly, the level of RGMB-AS1 expression in PC cells was abnormally high. RGMB-AS1 knockdown impeded PC cell proliferation and migration, but induced cell apoptosis, and RGMB-AS1 overexpression led the opposite consequences. RGMB-AS1 acted as a competing endogenous RNA (ceRNA) to sequester miR-574-3p and thereby regulated Pim-3 proto-oncogene, serine/threonine kinase (PIM3) expression. Conclusively, our work revealed the cancer-promoting function of RGMB-AS1 in PC and that the regulatory mechanism of the RGMB-AS1/miR-574-3p/PIM3 axis might contribute to novel biomarker development in PC treatment.NEW & NOTEWORTHY RGMB-AS1 promotes PC cell proliferation, elevates PC cell migration capacity, inhibits PC cell apoptosis, and promotes PC cell proliferation and migration but inhibits cell apoptosis via targeting miR-574-3p. PIM3 is directly targeted by miR-574-3p.

Proto-Oncogene Serine/Threonine Kinase PIM3 Promotes Cell Migration via Modulating Rho GTPase Signaling.

The proto-oncogene serine/threonine-protein kinase PIM3 plays critical roles in cancer, and it has been extensively exploited as a drug target. Here, we investigated the quantitative changes in the cellular proteome and phosphoproteome in liver cancer cells overexpressing PIM3 to obtain a better understanding of the regulatory functions of PIM3 and the underlying molecular mechanisms. This work depicted the landscape of gene expression and protein phosphorylation potentially regulated by PIM3. A signaling network analysis showed that PIM3 may coordinate various cellular processes, for example, signal transduction, cell cycle, apoptosis, and so forth. Intriguingly, quantitative phosphoproteomics revealed that the PIM3 overexpression elevated the phosphorylation of multiple Rho GTPase modulators that target RhoA, a central modulator of cell movement. Further investigations confirmed that PIM3 activated RhoA to subsequently regulate cytoskeletal rearrangements and cell migration. Taken together, this study comprehensively mapped the proteome and phosphoproteome regulated by PIM3 and revealed its role in promoting liver cancer cell migration and invasion by modulating Rho GTPase signaling.

PIM 3 kinase, a proto-oncogene product, regulates phosphorylation of the measles virus nucleoprotein tail domain at Ser 479 and Ser 510.

The tail domain of the measles virus (MeV) N protein is typically phosphorylated at S479 and S510. However, the protein kinase responsible for this phosphorylation has not been identified. To identify the protein kinase responsible, we conducted an in vitro kinase assay in the presence of various protein kinase inhibitors. Phosphorylation of S479 and S510 was suppressed in the presence of SP600125. We demonstrated that purified PIM 3 kinase, which is sensitive to SP600125, successfully phosphorylated both phosphorylation sites. Inhibitors of PIM kinase, CX6258 and LY294002, also suppressed phosphorylation of the N protein. These findings indicate that PIM 3 kinase is associated with the tail domain of the N protein and that PIM 3 kinase regulates N protein phosphorylation.

Downregulation of microRNA-124 prevents the development of acute liver failure through the upregulation of PIM-3.

NEW FINDINGS: • What is the central question of this study? Does miR-124 affect cell proliferation and apoptosis in acute liver failure (ALF) mice? • What is the main finding and its importance? Inhibiting miR-124 targets PIM-3 and thus upregulates its expression, consequently inhibiting liver cell apoptosis and promoting cell proliferation, ultimately preventing the progression of ALF. This highlights a promising competitive new target for ALF treatment. ABSTRACT: Acute liver failure (ALF) is a complicated syndrome frequently leading to dysfunction and failure of various organs. MicroRNAs (miRNAs) have played crucial roles in the development and progression of human diseases, including ALF. However, the potential role of miR-124 in ALF still remains elusive. Thus, we investigated the underlying mechanism by which miR-124 influences ALF in a mouse model of ALF. Initially, ALF mouse models were established using d-galactosamine and lipopolysaccharide. Then we detected the serum biochemical parameters of liver, and pathological characteristics and ultrastructure of liver tissues. Next, we determined miR-124 and PIM-3 expression in liver tissues and cells using RT-qPCR and western blot analysis. The interaction between miR-124 and PIM-3 was identified using the dual luciferase reporter gene assay. Subsequently, expression of miR-124 and PIM-3 in liver cells was altered to explore their effects on primary liver cell proliferation, the cell cycle and apoptosis. The results obtained showed that ALF mice exhibited a decreased cholinesterase level with increased levels of alanine aminotransferase, aspartate transaminase and total bilirubin as well as abundant liver cell apoptosis and necrosis. miR-124 was upregulated while PIM-3 was downregulated in ALF tissues and cells. Besides, the PIM-3 gene was a target of miR-124 and was inhibited by miR-124. Overexpression of miR-124 or silencing of PIM-3 reduced Bcl-2 expression but elevated tumour necrosis factor α expression, and resulted in a reduction in liver cell proliferation but an increase in cell apoptosis in ALF mice. Altogether, miR-124 functions as a disease-promoting miRNA with potential in stimulating ALF by targeting PIM-3.

Cholesterol regulates cell proliferation and apoptosis of colorectal cancer by modulating miR-33a-PIM3 pathway.

The relationship between colorectal cancer (CRC) and cholesterol has been confirmed for many years, but the mechanism was not very clear. miR-33a was important in cholesterol metabolism and was abnormally expressed in many tumors, thus our study hypothesized that cholesterol effect on CRC by regulating miR-33a and its target gene PIM3, and verify it by series of assay. From results of CCK8 and flow cytometry, we confirmed cholesterol can stimulate CRC cell proliferation, promote cell cycle progression and inhibit cell apoptosis. miR-33a and SREBP2 mRNA expression were inhibited by cholesterol, and when cells transfected with miR-33a mimics or inhibitor the effect of cholesterol appeared a significant difference than before. In addition, PIM3 showed up-regulation with cholesterol treatment, and it was proved to be the target gene of miR-33a by dual luciferase reporter assay, it modulated CRC cells proliferation and apoptosis by phosphorylating p27, p21 and Bad protein. Thus, it inferred that cholesterol can regulate CRC development by miR-33a-PIM3 pathway.

AZD1208, a Pan-Pim Kinase Inhibitor, Has Anti-Growth Effect on 93T449 Human Liposarcoma Cells via Control of the Expression and Phosphorylation of Pim-3, mTOR, 4EBP-1, S6, STAT-3 and AMPK.

Overexpression of Pim kinases has an oncogenic/pro-survival role in many hematological and solid cancers. AZD1208 is a pan-Pim kinase inhibitor that has anti-cancer and anti-adipogenic actions. Here, we investigated the effects of AZD1208 on the growth of 93T449 cells, a differentiated human liposarcoma cell line. At 20 µM, AZD1208 was cytotoxic (cytostatic) but not apoptotic, reducing cell survival without DNA fragmentation, caspase activation or increasing cells in the sub G1 phase; known apoptotic parameters. Notably, AZD1208 reduced phosphorylation of signal transducer and activator of transcription-3 (STAT-3) in 93T449 cells. STAT-3 inhibition by AG490, a JAK2/STAT-3 inhibitor similarly reduced cell survival. AZD1208 down-regulated phosphorylation of mammalian target of rapamycin (mTOR) and ribosomal S6 while up-regulated eukaryotic initiation factor-2α (eIF-2α). In addition, AZD1208 induced a LKB-1-independent AMPK activation, which was crucial for its cytostatic effect, as knock-down of AMPK greatly blocked AZD1208s ability to reduce cell survival. AZD1208 had no effect on expression of two members of Pim kinase family (Pim-1 and Pim-3) but inhibited phosphorylation of 4EBP-1, a downstream effector of Pim kinases. Importantly, a central role for Pim-3 in the actions of AZD1208 was confirmed by knock-down, which not only reduced 93T449 cell survival but also led to the inhibition of 4EBP-1, mTOR, eIF-2α and STAT-3, along with the activation of AMPK. In summary, this is the first report demonstrating that AZD1208 inhibits growth of liposarcoma cells and that this activity is mediated through Pim-3 kinase, STAT-3, mTOR, S6 and AMPK expression and phosphorylation pathways.

Discovery and evaluation of 3,5-disubstituted indole derivatives as Pim kinase inhibitors.

Pim kinases are promising therapeutic targets for the treatment of hematological cancers. A potent Pim kinase inhibitor 7f, derived from meridianin C, was further optimized by the replacement of 2-aminopyrimidine with substituted benzene. The optimization of the C-3 and C-5 positions of indole yielded compound 43 with improved cellular potency and high selectivity against a panel of 14 different kinases.

Expression and significance of Pim-3 kinase in adult T-cell leukemia.

BACKGROUND: Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia (ATL). Viral Tax protein plays a major role in ATL development. Pim family of serine/threonine kinases is composed of Pim-1, -2, and -3. The potential of Pim family as a target in ATL was analyzed. METHODS: RT-PCR and Western blotting were used to determine the expression of Pim kinases, Tax, and intracellular signal molecules. Knockdown of Pim-3 and RelA was performed using small interfering RNA. The effects on cell proliferation, viability, cell cycle, and apoptosis were analyzed by WST-8, propidium iodide, and APO2.7 assay. NF-κB DNA binding activity was investigated by electrophoretic mobility shift assay. RESULTS: Pim-3 expression was restricted to HTLV-1-infected T-cell lines. Tax induced Pim-3 expression through NF-κB. Knockdown of Pim-3 showed growth inhibition of HTLV-1-infected T cells. NJC97-NH, a novel inhibitor of the Pim-1/3 kinases, inhibited cell viability. NJC97-NH induced G2/M cell cycle arrest associated with downregulation of cyclin A and cyclin B1 expression, as well as apoptosis accompanied with downregulation of XIAP and Mcl-1 expression through inhibition of NF-κB pathway, mediated through decrease in IκBα and RelA phosphorylation. CONCLUSION: Pim-3 is a potentially suitable target for the development of novel therapeutic agents against ATL.

Pim-3 contributes to radioresistance through regulation of the cell cycle and DNA damage repair in pancreatic cancer cells.

Resistance of cancer cells to chemoradiotherapy is a major clinical problem in pancreatic cancer treatment. Therefore, understanding the molecular basis of cellular resistance and identifying novel targets are essential for improving treatment efficacy for pancreatic cancer patients. Previous studies have demonstrated a significant role for Pim-3 in pancreatic cancer survival against gemcitabine-induced genotoxic stress. Here, we observed that radiation treatment enhanced Pim-3 expression in human pancreatic cancer cells in vitro. Stable overexpression of Pim-3 in pancreatic cancer cells significantly protected cells against radiation treatment by attenuating G2/M phase cell cycle arrest and DNA damage response. Silencing of Pim-3 expression significantly elevated the phosphorylation of histone variant H2AX, a marker of DNA double strand breaks, and decreased the activation of ataxia-telangiectasia-mutated (ATM) kinase, along with its downstream targets, eventually enhancing the radiosensitivity of human pancreatic cancer cells in vitro and in vivo. Hence, we demonstrated a novel function for Pim-3 in human pancreatic cancer cell survival against radiation. Targeting Pim-3 may be a promising way to improve treatment efficacy in combination with radiotherapy in human pancreatic cancer.

Expression of Pim-3 in colorectal cancer and its relationship with prognosis.

There is increasing evidence suggesting that the establishment of Pim-3 is involved in tumorigenesis. This study aimed to investigate the expression and clinicopathological significance of Pim-3 in colorectal cancer (CRC). Clinical pathology data were collected from 410 CRC patients who received radical resection and were pathologically confirmed at the Sun Yat-Sen University Cancer Center between October 2002 and December 2008. We compared the expression Pim-3 in the primary focus and liver metastasis and investigated the correlations with other clinical-pathological factors. Multivariate analysis showed that perioperative blood transfusion, local invasion, lymph node and liver metastasis, and Pim-3 expression were independent prognostic factors. The expression of Pim-3 in CRC was higher than that in normal tissues. Patients with positive expression had significant decreases in 5-year survival. Pim-3 expression showed a positive correlation with tumor cell differentiation, local infiltration, and lymph node and liver metastasis. In conclusion, Pim-3 might serve as a novel target and prognosis factor for colorectal cancer.

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.

Design and synthesis of an in vivo-efficacious PIM3 kinase inhibitor as a candidate anti-pancreatic cancer agent.

Serine/threonine kinase PIM3 is a potential therapeutic target for pancreatic cancer. Here, we describe the evolution of our previous PIM1 inhibitor 1 into PIM3 inhibitor 11 guided by use of the crystal structure of PIM1 as a surrogate to provide a basis for rational modification. Compound 11 potently inhibits PIM3 kinase activity, as well as growth of several pancreatic cancer cell lines. In a mouse xenograft model, 11 inhibited growth of human pancreatic cancer cell line PCI66 with negligible body weight loss. Thus, 11 appears to be a promising lead compound for further optimization to develop new anti-pancreatic cancer agents.

Pediatric Critical Care Illness Severity Toolkit: Stata Commands for Calculation of Pediatric Index of Mortality and Pediatric Logistic Organ Dysfunction Scores.

Introduction: Illness severity scoring tools, such as PRISM III/IV, PIM-3, and PELOD-2, are widely used in pediatric critical care research. However, their application is hindered by complex calculation processes, privacy concerns with third-party online calculators, and challenges in accurate implementation within statistical packages. Methods: We have developed a comprehensive, open-source toolkit for implementing the PIM-3, Simplified PIM-3, and PELOD-2 scores. The toolkit includes the pim3 and pelod2 commands and is compatible with Stata versions 12 and above. It features robust data validation, error messaging, a graphical interface, and support for SI and Imperial units. The toolkit's accuracy was validated through unit testing and synthetic data, comparing results with existing implementations. Results: In performance tests, the toolkit exhibited a median processing time of 21.82 seconds for PELOD-2, 14.06 seconds for PIM-3, and 9.74 seconds for Simplified PIM-3, when applied to datasets of 10,000,000 records. It consistently achieved 100% accuracy in both synthetic data tests and manual spot checks. Conclusion: The toolkit decreases processing time and improves accuracy in calculating pediatric critical care severity scores such as PELOD-2, PIM-3, and Simplified PIM-3. Its application in large datasets and validation highlights its utility as a tool for streamlining pediatric critical care research.

PIM3 regulates myocardial ischemia/reperfusion injury via ferroptosis.

BACKGROUND: Myocardial ischemia/reperfusion (I/R) injury is closely related with cardiovascular diseases; however, the underlying pathogenic mechanisms remain not fully understood. This study sought to investigate the effect and mechanisms of PIM3 implicated in myocardial I/R injury using a rat model of myocardial I/R injury and a cell model of oxygen-glucose deprivation/reoxygenation (OGD/R) induction. METHODS: The morphology changes were detected by HE staining while cell viability was accessed by the CCK-8 method. The characteristics of ferroptosis were evaluated by ROS production, MDA content, SOD level, iron content, TfR1, FTH1, and GPX4 expression. RESULTS: Myocardial I/R operation increased myocardial tissue damage in rats, while OGD/R treatment reduced the viability of H9c2 cells. Both myocardial I/R operation and OGD/R stimulation increased ferroptosis, as demonstrated by elevated ROS, MDA, iron content, decreased SOD level, upregulation of TfR1, and downregulation of FTH1 and GPX4. Additionally, myocardial I/R modeling or OGD/R treatment enhanced the expression of PIM3. Silencing of PIM3 inhibited ferroptosis, which resulted in alleviated myocardial I/R-induced damage and improved H9c2 cell survival. CONCLUSIONS: Our findings highlight a vital role of PIM3 in myocardial I/R injury, indicating that PIM3-targeting ferroptosis may be a promising target for the development of novel therapies of myocardial I/R injury-associated diseases.

Targeting PIM kinases in cancer therapy: An update on pharmacological small-molecule inhibitors.

PIM kinases, a serine/threonine kinase family with three isoforms, has been well-known to participate in multiple physiological processes by phosphorylating various downstream targets. Accumulating evidence has recently unveiled that aberrant upregulation of PIM kinases (PIM1, PIM2, and PIM3) are closely associated with tumor cell proliferation, migration, survival, and even resistance. Inhibiting or silencing of PIM kinases has been reported have remarkable antitumor effects, such as anti-proliferation, pro-apoptosis and resensitivity, indicating the therapeutic potential of PIM kinases as potential druggable targets in many types of human cancers. More recently, several pharmacological small-molecule inhibitors have been preclinically and clinically evaluated and showed their therapeutic potential; however, none of them has been approved for clinical application so far. Thus, in this perspective, we focus on summarizing the oncogenic roles of PIM kinases, key signaling network, and pharmacological small-molecule inhibitors, which will provide a new clue on discovering more candidate antitumor drugs targeting PIM kinases in the future.

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.

Pim-3 promotes the growth of human pancreatic cancer in the orthotopic nude mouse model through vascular endothelium growth factor.

BACKGROUND: As one of the most lethal cancers, pancreatic cancer presents poor prognosis with an overall 5-y survival of less than 5%. We previously reported that Pim-3, a member of the proto-oncogene Pim family that encodes serine/threonine kinases, is aberrantly expressed in human pancreatic cancer lesions. In the current study, we investigated the role of Pim-3 in promoting tumor growth and angiogenesis in an orthotopic nude mouse model of human pancreatic cancer. METHODS: We constructed retroviral vectors for human Pim-3 and a kinase-dead mutant of human Pim-3 (K69M); the retroviral supernatants generated from these vectors were then used to infect the human pancreatic cancer cell line MiaPaCa-2 to establish stable cell lines. We assessed cell proliferation using CCK-8, tumor growth, and angiogenesis in vivo in an orthotopic mouse model of pancreatic cancer. While tumor size was measured using magnetic resonance imaging, the tumor tissues were excised for protein extraction and histological analysis to detect vascular endothelium growth factor (VEGF) expression and vessel density. RESULTS: We established an orthotopic nude mouse model of human pancreatic cancer. We observed that Pim-3 promoted the proliferation of human pancreatic cancer cells, both in vitro and in vivo. Moreover, Pim-3 is required for vasculogenesis of primary human pancreatic tumors in vivo and promotion of angiogenesis through the induction of VEGF expression. CONCLUSIONS: Pim-3 can promote tumor growth and angiogenesis by stimulating the VEGF pathway.