The Novel PIM1 Inhibitor NMS-P645 Reverses PIM1-Dependent Effects on TMPRSS2/ERG Positive Prostate Cancer Cells And Shows Anti-Proliferative Activity in Combination with PI3K Inhibition

Prostate cancer immunotherapy: Improving clinical outcomes with a multi-pronged approach

Cancer immunotherapy has gained traction in recent years owing to remarkable tumor clearance in some patients. Despite the notable success of immune checkpoint blockade (ICB) in multiple malignancies, engagement of the immune system for targeted prostate cancer (PCa) therapy is still in its infancy. Multiple factors contribute to limited response, including the heterogeneity of PCa, the cold tumor microenvironment, and a low number of neoantigens. Significant effort is being invested in improving immune-based PCa therapies. This review is a summary of the status of immunotherapy in treating PCa, with a discussion of multiple immune modalities, including vaccines, adoptively transferred T cells, and bispecific T cell engagers, some of which are undergoing clinical trials. In addition, this review also focuses on emerging mechanism-based small-molecule tyrosine kinase inhibitors with immune modulatory properties that, either as single agents or in combination with other immunotherapies, have the potential to improve clinical outcomes.

Construction and evaluation of a prognostic risk assessment model of gastric cancer by using hypoxia features

In this study, mRNA expression of gastric cancer tissue and clinical data of patients in TCGA-STAD dataset were used, together with the hypoxia-related gene sets in the MsigDB database, to screen hypoxia-related differentially expressed genes (DEGs) in GC. Thereafter, univariate and multivariate Cox regression analyses were carried out on hypoxia-related DEGs. The optimal feature genes related to prognosis were obtained to construct a prognostic risk assessment model. According to the model, the riskScore of GC patients was measured, and GC samples were assigned into high- and low-risk groups in accordance with the median riskScore. Based on the Kaplan-Meier curve and Receiver operating characteristic curve, validity of the prognostic risk assessment model was measured. Gene set enrichment analysis was performed on the two risk groups through Gene set enrichment analysis software. The results revealed that in the high-risk group, 9 signaling pathways were remarkably activated in several terms, like focal adhesion, extracellular matrix receptor interaction, Cell adhesion molecules cams, Cytokine-cytokine receptor interaction, TGF-beta signaling pathway, NOD-like receptor signaling pathway, JAK-STAT signaling pathway, Toll-like receptor signaling pathway and MAPK signaling pathway. In combination with riskScore and clinical factors, univariate and multivariate Cox regression analyses verified the independence of the model. Meanwhile, a nomogram was constructed to predict the 1-, 3- and 5-year survival of GC patients. The calibration curve indicated that the survival status predicted by the nomogram fitted better with actual survival status. On the whole, the prognostic risk model of GC on the basis of hypoxia-related genes demonstrated good predictive ability. It can provide more powerful technical support for clinicians to make prognostic determination and therapeutic plans.

PIM1/STAT3 axis: a potential co-targeted therapeutic approach in triple-negative breast cancer

Triple-negative breast cancer lacks an expression of ER, PR, and Her-2, has a poor prognosis, and there are no target therapies available. Therapeutic options to treat TNBC are limited and urgently needed. Strong evidence indicates that molecular signaling pathways have a significant function to regulate biological mechanisms and their abnormal expression endows with the development of cancer. PIM kinase is overexpressed in various human cancers including TNBC which is regulated by various signaling pathways that are crucial for cancer cell proliferation and survival and also make PIM kinase as an attractive drug target. One of the targets of the STAT3 signaling pathway is PIM1 that plays a key role in tumor progression and transformation. In this review, we accumulate the current scenario of the PIM-STAT3 axis that provides insights into the PIM1 and STAT3 inhibitors which can be developed as potential co-inhibitors as prospective anticancer agents.

Phytoconstituents and Medicinal Plants for Anticancer Drug Discovery: Computational Identification of Potent Inhibitors of PIM1 Kinase

Natural products, medicinal plants, and phytoconstituents serve as important sources and accelerators for anticancer drug discovery, especially when they are combined with virtual screening and molecular simulations against molecular drug targets. Proto-oncogene serine/threonine-protein kinase Pim1 (PIM1) is involved in cell survival and proliferation, with great relevance for oncogenesis. PIM1 plays a major role in the progression of various common complex human cancers, including prostate cancer, acute myeloid leukemia, and other hematopoietic malignancies. The overexpression of PIM1 leads to cancer progression, and thus it is considered as a potential target for drug design and development purposes. Here, we report original in silico findings by employing structure-based virtual screening to discover potential phytoconstituents from the medicinal plants-based compounds, which could inhibit the PIM1 activity, using the IMPPAT (a curated database of Indian Medicinal Plants, Phytochemistry And Therapeutics) database. The initial hits were selected based on their binding affinity toward PIM1 calculated through the molecular docking approach. Subsequently, interaction analyses and molecular dynamics (MD) simulation for 100 ns was carried out to study the conformational dynamics and complex stability of PIM1 with the identified compounds. Importantly, we found that PIM1 forms stable protein-ligand complexes with the phytoconstituents Dehydrotectol and Nordracorubin in particular. Our findings suggest that identified phytoconstituents Dehydrotectol and Nordracorubin bind to PIM1 in ATP-competitive binding mode. These findings and the compounds reported herein warrant further exploration as promising scaffolds for anticancer drug design, discovery, and development.

PIM Kinases in Multiple Myeloma

Multiple myeloma (MM) remains an incurable disease and novel therapeutic agents/approaches are urgently needed. The PIM (Proviral insertion in murine malignancies) serine/threonine kinases have 3 isoforms: PIM1, PIM2, and PIM3. PIM kinases are engaged with an expansive scope of biological activities including cell growth, apoptosis, drug resistance, and immune response. An assortment of molecules and pathways that are critical to myeloma tumorigenesis has been recognized as the downstream targets of PIM kinases. The inhibition of PIM kinases has become an emerging scientific interest for the treatment of multiple myeloma and several PIM kinase inhibitors, such as SGI-1776, AZD1208, and PIM447 (formerly LGH447), have been developed and are under different phases of clinical trials. Current research has been focused on the development of a new generation of potent PIM kinase inhibitors with appropriate pharmacological profiles reasonable for human malignancy treatment. Combination therapy of PIM kinase inhibitors with chemotherapeutic appears to create an additive cytotoxic impact in cancer cells. Notwithstanding, the mechanisms by which PIM kinases modulate the immune microenvironment and synergize with the immunomodulatory agents such as lenalidomide have not been deliberately depicted. This review provides a comprehensive overview of the PIM kinase pathways and the current research status of the development of PIM kinase inhibitors for the treatment of MM. Additionally, the combinatorial effects of the PIM kinase inhibitors with other targeted agents and the promising strategies to exploit PIM as a therapeutic target in malignancy are highlighted.

Expression and ERG regulation of PIM kinases in prostate cancer

The three oncogenic PIM family kinases have been implicated in the development of prostate cancer (PCa). The aim of this study was to examine the mRNA and protein expression levels of PIM1, PIM2, and PIM3 in PCa and their associations with the MYC and ERG oncogenes. We utilized prostate tissue specimens of normal, benign prostatic hyperplasia (BPH), prostatic intraepithelial neoplasia (PIN), untreated PCa, and castration‐resistant prostate cancer (CRPC) for immunohistochemical (IHC) analysis. In addition, we analyzed data from publicly available mRNA expression and chromatin immunoprecipitation sequencing (ChIP‐Seq) datasets. Our data demonstrated that PIM expression levels are significantly elevated in PCa compared to benign samples. Strikingly, the expression of both PIM1 and PIM2 was further increased in CRPC compared to PCa. We also demonstrated a significant association between upregulated PIM family members and both the ERG and MYC oncoproteins. Interestingly, ERG directly binds to the regulatory regions of all PIM genes and upregulates their expression. Furthermore, ERG suppression with siRNA reduced the expression of PIM in PCa cells. These results provide evidence for cooperation of PIM and the MYC and ERG oncoproteins in PCa development and progression and may help to stratify suitable patients for PIM‐targeted therapies.

Co-targeting PIM and PI3K/mTOR using multikinase inhibitor AUM302 and a combination of AZD-1208 and BEZ235 in prostate cancer

PIM and PI3K/mTOR pathways are often dysregulated in prostate cancer, and may lead to decreased survival, increased metastasis and invasion. The pathways are heavily interconnected and act on a variety of common effectors that can lead to the development of resistance to drug inhibitors. Most current treatments exhibit issues with toxicity and resistance. We investigated the novel multikinase PIM/PI3K/mTOR inhibitor, AUM302, versus a combination of the PIM inhibitor, AZD-1208, and the PI3K/mTOR inhibitor BEZ235 (Dactolisib) to determine their impact on mRNA and phosphoprotein expression, as well as their functional efficacy. We have determined that around 20% of prostate cancer patients overexpress the direct targets of these drugs, and this cohort are more likely to have a high Gleason grade tumour (≥ Gleason 8). A co-targeted inhibition approach offered broader inhibition of genes and phosphoproteins in the PI3K/mTOR pathway, when compared to single kinase inhibition. The preclinical inhibitor AUM302, used at a lower dose, elicited a comparable or superior functional outcome compared with combined AZD-1208 + BEZ235, which have been investigated in clinical trials, and could help to reduce treatment toxicity in future trials. We believe that a co-targeting approach is a viable therapeutic strategy that should be developed further in pre-clinical studies.

PIM kinase inhibition: co-targeted therapeutic approaches in prostate cancer

PIM kinases have been shown to play a role in prostate cancer development and progression, as well as in some of the hallmarks of cancer, especially proliferation and apoptosis. Their upregulation in prostate cancer has been correlated with decreased patient overall survival and therapy resistance. Initial efforts to inhibit PIM with monotherapies have been hampered by compensatory upregulation of other pathways and drug toxicity, and as such, it has been suggested that co-targeting PIM with other treatment approaches may permit lower doses and be a more viable option in the clinic. Here, we present the rationale and basis for co-targeting PIM with inhibitors of PI3K/mTOR/AKT, JAK/STAT, MYC, stemness, and RNA Polymerase I transcription, along with other therapies, including androgen deprivation, radiotherapy, chemotherapy, and immunotherapy. Such combined approaches could potentially be used as neoadjuvant therapies, limiting the development of resistance to treatments or sensitizing cells to other therapeutics. To determine which drugs should be combined with PIM inhibitors for each patient, it will be key to develop companion diagnostics that predict response to each co-targeted option, hopefully providing a personalized medicine pathway for subsets of prostate cancer patients in the future.

Human papillomavirus insertions identify the PIM family of serine/threonine kinases as targetable driver genes in head and neck squamous cell carcinoma

Human papillomavirus (HPV) insertions in cancer genomes have been linked to various forms of focal genomic instability and altered expression of neighboring genes. Here we tested the hypothesis that investigation of HPV insertions in a head and neck cancer squamous cell carcinoma (HNSCC) cell line would identify targetable driver genes contributing to oncogenesis of other HNSCC. In the cell line UPCI:SCC090 HPV16 integration amplified the PIM1 serine/threonine kinase gene ~16-fold, thereby increasing transcript and protein levels. We used genetic and pharmacological approaches to inhibit PIM kinases in this and other HNSCC cell lines. Knockdown of PIM1 transcripts by transfected short hairpin RNAs reduced UPCI:SCC090 viability. CRISPR/Cas9-mediated mutagenesis of PIM1 caused cell cycle arrest and apoptosis. Pharmacological inhibition of PIM family kinases decreased growth of UPCI:SCC090 and additional HNSCC cell lines in vitro and a xenograft UPCI:SCC090 model in vivo. Based on established interactions between intracellular signaling pathways and relatively high levels of gene expression in almost all HNSCC, we also evaluated combinations of PIM kinase and epidermal growth factor receptor (EGFR) inhibitors. Dual inhibition of these pathways resulted in supra-additive cell death. These data support clinical testing of PIM inhibitors alone or in combination in HNSCC.

PIM-1 kinase: a potential biomarker of triple-negative breast cancer

Triple-negative breast cancer is associated with a poor prognosis, and effective biomarkers for targeted diagnosis and treatment are lacking. The tumorigenicity of the provirus integration site for Moloney murine leukemia virus 1 (PIM-1) gene has been studied for many years. However, its significance in breast cancer remains unclear. In this review we briefly summarized the physiological characteristics and regulation of PIM-1 kinase, and subsequently focused on the role of PIM-1 in tumors, especially breast cancer. Oncogene PIM-1 was found to be upregulated in breast cancer, especially in triple-negative breast cancer. Moreover, it is involved in tumorigenesis and the development of drug resistance, and linked to poor prognosis. A highly selective probe targeting PIM-1 for imaging has emerged, suggesting that PIM-1 may be a potential biomarker for the accurate diagnosis and targeted therapy of triple-negative breast cancer.

Pim1 promotes cell proliferation and regulates glycolysis via interaction with MYC in ovarian cancer

Background

Ovarian cancer (OC) is the leading cause of death among women with gynecologic malignancies. Recent studies have highlighted the role of Pim1, which belongs to a group of constitutively activated serine/threonine kinases, in cancer development. However, the effect of Pim1 in OC is largely unclear.

Methods

OC cell lines with Pim1 overexpression or knockdown were constructed with len-tivirus transduction. Cell Counting Kit-8, colony formation, glycolysis stress test and in vivo mice models were carried out to assess the effect of Pim1 on OC biological functions. Co-immunoprecipitation assay coupled with western blot were performed to explore the intrinsic mechanisms of Pim1 in OC. Bioinformatic analysis was then performed to evaluate the expression and prognostic value of Pim1.

Results

We present the first evidence that silencing or overexpressing Pim1 can suppress or promote, respectively, OC cell proliferation. Furthermore, we demonstrated that Pim1 can significantly enhance glycolysis in OC cells. In vivo experiments further confirmed that knockdown of Pim1 inhibits the growth of tumors derived from the SKOV3 cell line. To search for the underlying molecular mechanism, we examined the effect of Pim1 on MYC, a pivotal gene in glycolysis, and observed that Pim1-mediated phosphorylation of c-Myc activated the expression of glycolysis-associated key genes such as PGK1 and LDHA. Moreover, we found that the Pim1 inhibitor SMI4a induced chemosensitization to cisplatin. Clinically, Pim1 was also overexpressed in OC and correlated with poor overall survival by bioinformatics analysis.

Conclusion

Together, these results suggest that Pim1 contributes to proliferation and gly-colysis in OC via interaction with MYC and may serve as a potential target in the treatment of OC patients.

The dual inhibitor of the phosphoinositol-3 and PIM kinases, IBL-202, is effective against chronic lymphocytic leukaemia cells under conditions that mimic the hypoxic tumour microenvironment

Despite significant advances in treatment, chronic lymphocytic leukaemia (CLL) remains an incurable disease. Ibrutinib and idelalisib, which inhibit Bruton Tyrosine kinase (BTK) and phosphoinositol-3 (PI3) kinase-δ respectively, have become important treatment options for the disease and demonstrate the potential of targeting components of the B-cell receptor-signalling pathway. IBL-202 is a dual inhibitor of the PIM and PI3 kinases. Synergy between the pan-PIM inhibitor, pPIMi, and idelalisib against a range of haematological cell lines and primary CLL cells supports the rationale for preclinical studies of IBL-202 in CLL. Importantly, IBL-202, but not idelalisib, was cytotoxic against CLL cells under in vitro conditions that mimic the hypoxic tumour microenvironment. The significant effects of IBL-202 on CD49d and CXCR4 expression and migration, cycle and proliferation of CLL cells suggest the drug may also interfere with the migratory and proliferative capacity of the leukaemic cells. Collectively, these data demonstrate that dual inhibition of the PIM and PI3 kinases by IBL-202 may be an effective strategy for targeting CLL cells, particularly within the environmental niches known to confer drug-resistance.