Pim-3 Regulates Stemness of Pancreatic Cancer Cells via Activating STAT3 Signaling Pathway

ICAM1 (CD54) Contributes to the Metastatic Capacity of Gastric Cancer Stem Cells

Gastric cancer is the fourth leading cause of cancer deaths worldwide. The presence of chemoresistant cells has been used to explain this high mortality rate. These higher tumorigenic and chemoresistant cells involve cancer stem cells (CSCs), which have the potential for self-renewal, a cell differentiation capacity, and a greater tumorigenic capacity. Our research group identified gastric cancer stem cells (GCSCs) with the CD24+CD44+CD326+ICAM1+ immunophenotype isolated from gastric cancer patients. Interestingly, this GCSC immunophenotype was absent in cells isolated from healthy people, who presented a cell population with a CD24+CD44+CD326+ immunophenotype, lacking ICAM1. We aimed to explore the role of ICAM1 in these GCSCs; for this purpose, we isolated GCSCs from the AGS cell line and generated a GCSC line knockout for ICAM1 using CRISPR/iCas9, which we named GCSC-ICAM1KO. To assess the role of ICAM1 in the GCSCs, we analyzed the migration, invasion, and chemoresistance capabilities of the GCSCs using in vitro assays and evaluated the migratory, invasive, and tumorigenic properties in a zebrafish model. The in vitro analysis showed that ICAM1 regulated STAT3 activation (pSTAT3-ser727) in the GCSCs, which could contribute to the ability of GCSCs to migrate, invade, and metastasize. Interestingly, we demonstrated that the GCSC-ICAM1KO cells lost their capacity to migrate, invade, and metastasize, but they exhibited an increased resistance to a cisplatin treatment compared to their parental GCSCs; the GCSC-ICAM1KO cells also exhibited an increased tumorigenic capability in vivo.

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.

The Role of PIM Kinases in Pediatric Solid Tumors

PIM kinases have been identified as potential therapeutic targets in several malignancies. Here, we provide an in-depth review of PIM kinases, including their structure, expression, activity, regulation, and role in pediatric carcinogenesis. Also included is a brief summary of the currently available pharmaceutical agents targeting PIM kinases and existing clinical trials.

Ventilagolin Suppresses Migration, Invasion and Epithelial-Mesenchymal Transition of Hepatocellular Carcinoma Cells by Downregulating Pim-1

Objective

Inhibition of tumor metastasis is a useful strategy to improve the efficacy of cancer therapy. Ventilagolin, a natural 1, 4-naphthoquinone derivative extracted from Ventilago leiocarpa Benth, has shown promising antitumor effects in previous studies. However, the effects and underlying mechanisms of Ventilagolin against migration, invasion and epithelial-mesenchymal transition (EMT) of hepatocellular carcinoma (HCC) remain unclear. The present study has examined these effects and determined whether the proto-oncogene Pim-1 is involved.

Methods

The effects of Ventilagolin on migration, invasion, Pim-1 and EMT-related proteins (eg, E-cadherin, N-cadherin, Vimentin) expression were assessed by scratch wound healing, Transwell, qRT-PCR and Western blot assays, respectively. Pim-1 stably overexpressed HepG2 and SMMC-7721 cells were generated to explore whether Ventilagolin inhibited migration, invasion and EMT of HCC cells via regulating Pim-1. Subcutaneous xenograft tumor model in nude mice was established. Histopathological changes of tumor tissues were examined by H&E staining and expressions of Pim-1 and EMT-related proteins were detected by immunohistochemistry.

Results

Ventilagolin significantly (P < 0.01) reduced the expression of Pim-1 levels in HepG2 and SMMC-7721 cells. Compared with the control group, the migration and invasion abilities of Pim-1-overexpressing HepG2 and SMMC-7721 cells were significantly (P < 0.05, P < 0.01) enhanced, the expression of E-cadherin was decreased (P < 0.01), and the levels of N-cadherin and Vimentin were upregulated (P < 0.05, P < 0.01). Ventilagolin treatment effectively reversed these effects of Pim-1 overexpression. In vivo experiments showed that Ventilagolin could effectively suppress HCC tumor growth, downregulate Pim-1, N-cadherin and Vimentin expression, and upregulate E-cadherin expression.

Conclusion

Ventilagolin suppresses HCC cell proliferation, migration and invasion and reverses EMT process by downregulating Pim-1, suggesting Ventilagolin is a potential therapeutic agent for treatment of HCC.

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.

PIM kinases mediate resistance to cisplatin chemotherapy in hepatoblastoma

Despite increasing incidence, treatment for hepatoblastoma has not changed significantly over the past 20 years. Chemotherapeutic strategies continue to rely on cisplatin, as it remains the most active single agent against hepatoblastoma. However, chemoresistance remains a significant challenge with 54–80% of patients developing resistance to chemotherapy after 4–5 cycles of treatment. Stem cell-like cancer cells (SCLCCs) are a subset of cells thought to play a role in chemoresistance and disease recurrence. We have previously demonstrated that Proviral Integration site for Moloney murine leukemia virus (PIM) kinases, specifically PIM3, play a role in hepatoblastoma cell proliferation and tumor growth and maintain the SCLCC phenotype. Here, we describe the development of a cisplatin-resistant hepatoblastoma xenograft model of the human HuH6 cell line and a patient-derived xenograft, COA67. We provide evidence that these cisplatin-resistant cells are enriched for SCLCCs and express PIM3 at higher levels than cisplatin-naïve cells. We demonstrate that PIM inhibition with AZD1208 sensitizes cisplatin-resistant hepatoblastoma cells to cisplatin, enhances cisplatin-mediated apoptosis, and decreases the SCLCC phenotype seen with cisplatin resistance. Together, these findings indicate that PIM inhibition may be a promising adjunct in the treatment of hepatoblastoma to effectively target SCLCCs and potentially decrease chemoresistance and subsequent disease relapse.

The presence of PIM3 increases hepatoblastoma tumorigenesis and tumor initiating cell phenotype and is associated with decreased patient survival

PURPOSE

Hepatoblastoma is the most common primary liver cancer of childhood and has few prognostic indicators. We have previously shown that Proviral Integration site for Moloney murine leukemia virus (PIM3) kinase decreased hepatoblastoma tumorigenicity. We sought to determine the effect of PIM3 overexpression on hepatoblastoma cells and whether expression of PIM3 correlated with patient/tumor characteristics or survival.

METHODS

The hepatoblastoma cell line, HuH6, and patient-derived xenograft, COA67, were utilized. Viability, proliferation, migration, sphere formation, and tumor growth in mice were assessed in PIM3-overexpressing cells. Immunohistochemistry was performed for PIM3 on patient samples. Correlation between stain score and clinical/pathologic characteristics was assessed.

RESULTS

PIM3 overexpression rescued the anti-proliferative effect observed with PIM3 knockdown. Sphere formation was increased in PIM3 overexpressing cells. Cells with PIM3 overexpression yielded larger tumors than those with empty vector. Seventy-four percent of samples expressed PIM3. There was no statistical difference in patient characteristics between subjects with strong versus weak PIM3 staining, but patients with strong PIM3 staining had decreased survival.

CONCLUSIONS

PIM3 expression plays a role in hepatoblastoma tumorigenesis. PIM3 was present in the majority of hepatoblastomas and higher PIM3 expression correlated with decreased survival. PIM3 warrants investigation as a therapeutic target and prognostic marker for hepatoblastoma.

PIM1 mediates epithelial-mesenchymal transition by targeting Smads and c-Myc in the nucleus and potentiates clear-cell renal-cell carcinoma oncogenesis

Emerging evidence has shown that the PIM serine/threonine kinase family, including PIM1, PIM2 and PIM3, is associated with tumour progression towards metastasis. PIM1, an attractive molecular target, has been identified as a potential prognostic biomarker for haematological and epithelial malignancies. However, to date, the potential regulatory roles and molecular mechanisms by which PIM1 affects the development and progression of cancers, including clear-cell renal-cell carcinoma (ccRCC), remain largely unknown. Herein, we present the first evidence that PIM1 is aberrantly overexpressed in human ccRCC tissues and cell lines and positively correlated with human ccRCC progression. In our study, depletion of PIM1 attenuated ccRCC cell proliferation, colony formation, migration, invasion and angiogenesis, suggesting that PIM1 expression may be a cancer-promoting event in ccRCC. Mechanistically, we observed that PIM1 could interact with Smad2 or Smad3 in the nucleus and subsequently phosphorylate Smad2 and Smad3 to induce the expression of transcription factors, including ZEB1, ZEB2, Snail1, Snail2 and Twist, to promote epithelial-mesenchymal transition (EMT). In addition, PIM1-mediated phosphorylation of c-Myc activates the expression of the above transcription factors to synergistically promote EMT but does not activate Smads. Collectively, our results demonstrate that aberrant expression of PIM1 contributes to ccRCC development and progression. Moreover, our data reveal a potential molecular mechanism in which PIM1 mediates crosstalk between signalling pathways, including different Smad proteins and c-Myc, which target downstream transcription factors (ZEB1, ZEB2, Snail1, Snail2 and Twist) to trigger EMT. Together, our data suggest that PIM1 may be a potential therapeutic target for ccRCC patients.