The role of PIM1/PIM2 kinases in tumors of the male reproductive system

Unveiling the multi-characteristic potential of hyper-productive suspension MDCK cells for advanced influenza A virus propagation

The global population faces persistent threats from influenza viruses, with vaccination remaining the most cost-effective preventive measure against influenza. Mammalian cell-based influenza vaccine production has garnered significant attention due to its enhanced safety profile, process controllability, and ability to circumvent adaptive mutations commonly associated with traditional egg-based vaccines, and the particular promise of suspension cell-based production systems for their convenience, economic viability, and scalability potential. Despite years of development and an increasing number of approved animal substrate-based vaccines, numerous challenges persist, especially the incomplete understanding of influenza virus amplification features in the producing cell lines. In previous research, we developed a high-titer suspension MDCK cell-based influenza virus production process and established a high-generation MDCK cell line (MDCK-HG). This study demonstrated enhanced productive capacity of MDCK-HG cells across diverse operational conditions. The maximum hemagglutination titer achieved 15.02 Log2HAU/100 μL for H9N2 strain and 12.55 Log2HAU/100 μL for H1N1 strain, which evidenced by a 56.95 % and a 189.79 % increase compared to the original suspension MDCK cells. Through kinetics analyses, transcriptomic profiling, and metabolic characterization, we identified the kinetic features of high-generation cell lines for efficient influenza virus production and discovered that the redistribution of cell cycles, enhanced anti-apoptotic capabilities, elevated membrane synthesis rates, and efficient energy metabolism likely contribute to their increased viral production capacity. These findings not only deepen our understanding of the influenza vaccine production process but also provide valuable guidance for future systematic metabolic engineering efforts aimed at establishing more robust vaccine production processes.

FDA-approved drugs as PIM-1 kinase inhibitors: A drug repurposed approach for cancer therapy

PIM-1 kinase, a member of the Serine/Threonine kinase family, has emerged as a promising therapeutic target in various cancers due to its role in promoting tumor growth and resistance to conventional therapies. In this study, we employed a structure-based approach to screen 3800 FDA-approved drugs to discover potential inhibitors of PIM-1. After an initial selection of 50 candidates based on high docking scores, four drugs, stanozolol, alfaxalone, rifaximin, and telmisartan, were identified as strong PIM-1 binders, interacting with key residues in the ATP-binding pocket of the kinase. To assess the stability of these interactions, we conducted all-atom molecular dynamic simulations, confirming favorable dynamics. Experimental validation via a kinase inhibition assay on recombinant PIM-1 showed that rifaximin significantly inhibited PIM-1 activity, with an IC50 of ∼26 μM. Fluorescence binding assays further demonstrated a strong binding affinity for rifaximin, with a binding constant, corroborated by isothermal titration calorimetry studies. Our findings suggest that rifaximin may serve as a potential repurposed drug for targeting PIM-1 in cancer treatment. However, further validations are required in a clinical setting before the final therapeutic implications.

Inhibition of PIM kinase in tumor associated macrophages suppresses inflammasome activation and sensitizes prostate cancer to immunotherapy

Immunotherapy has changed the treatment paradigm for many types of cancer, but immune checkpoint inhibitors (ICIs) have not shown benefit in prostate cancer (PCa). Chronic inflammation contributes to the immunosuppressive prostate tumor microenvironment (TME) and is associated with poor response to ICIs. The primary source of inflammatory cytokine production is the inflammasome. Here, we identify PIM kinases as important regulators of inflammasome activation in tumor associated macrophages (TAMs). Analysis of clinical data from a cohort of treatment naïve, hormone responsive PCa patients revealed that tumors from patients with high PIM1/2/3 display an immunosuppressive TME characterized by high inflammation (IL-1β and TNFα) and a high density of repressive immune cells, most notably TAMs. Strikingly, macrophage-specific knockout of PIM reduced tumor growth in syngeneic models of prostate cancer. Transcriptional analyses indicate that eliminating PIM from macrophages enhanced the adaptive immune response and increased cytotoxic immune cells. Combined treatment with PIM inhibitors and ICIs synergistically reduced tumor growth. Immune profiling revealed that PIM inhibitors sensitized PCa tumors to ICIs by increasing tumor suppressive TAMs and increasing the activation of cytotoxic T cells. Collectively, our data implicate macrophage PIM as a driver of inflammation that limits the potency of ICIs and provides preclinical evidence that PIM inhibitors are an effective strategy to improve the efficacy of immunotherapy in prostate cancer.

Differential abundance of microRNAs in seminal plasma extracellular vesicles (EVs) in Sahiwal cattle bull related to male fertility

Sahiwal cattle, known for their high milk yield, are propagated through artificial insemination (AI) using male germplasm, largely contingent on semen quality. Spermatozoa, produced in the testes, carry genetic information and molecular signals essential for successful fertilization. Seminal plasma, in addition to sperm, contains nano-sized lipid-bound extracellular vesicles (SP-EVs) that carry key biomolecules, including fertility-related miRNAs, which are essential for bull fertility. The current study focused on miRNA profiling of SP-EVs from high-fertile (HF) and low-fertile (LF) Sahiwal bulls. SP-EVs were isolated using size exclusion chromatography (SEC) and characterized by dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA). Western blotting detected the EV-specific protein markers TSG101 and CD63. The DLS analysis showed SP-EV sizes of 170-180 nm in HF and 130-140 nm in LF samples. The NTA revealed particle concentrations of 5.76 × 1010 to 5.86 × 1011 particles/mL in HF and 5.31 × 1010 to 2.70 × 1011 particles/mL in LF groups, with no significant differences in size and concentration between HF and LF. High-throughput miRNA sequencing identified 310 miRNAs in SP-EVs from both groups, with 61 upregulated and 119 downregulated in HF bull. Further analysis identified 41 miRNAs with significant fold changes and p-values, including bta-miR-1246, bta-miR-195, bta-miR-339b, and bta-miR-199b, which were analyzed for target gene prediction. Gene Ontology (GO) and KEGG pathway analyses indicated that these miRNAs target genes involved in transcription regulation, ubiquitin-dependent endoplasmic reticulum-associated degradation (ERAD) pathways, and signalling pathways. Functional exploration revealed that these genes play roles in spermatogenesis, motility, acrosome reactions, and inflammatory responses. qPCR analysis showed that bta-miR-195 had 80% higher expression in HF spermatozoa compared to LF, suggesting its association with fertility status (p < 0.05). In conclusion, this study elucidates the miRNA cargoes in SP-EVs as indicators of Sahiwal bull fertility, highlighting bta-miR-195 as a potential fertility factor among the various miRNAs identified.

A review on structure-function mechanism and signaling pathway of serine/threonine protein PIM kinases as a therapeutic target

The proviral integration for the Moloney murine leukemia virus (PIM) kinases, belonging to serine/threonine kinase family, have been found to be overexpressed in various types of cancers, such as prostate, breast, colon, endometrial, gastric, and pancreatic cancer. The three isoforms PIM kinases i.e., PIM1, PIM2, and PIM3 share a high degree of sequence and structural similarity and phosphorylate substrates controlling tumorigenic phenotypes like proliferation and cell survival. Targeting short-lived PIM kinases presents an intriguing strategy as in vivo knock-down studies result in non-lethal phenotypes, indicating that clinical inhibition of PIM might have fewer adverse effects. The ATP binding site (hinge region) possesses distinctive attributes, which led to the development of novel small molecule scaffolds that target either one or all three PIM isoforms. Machine learning and structure-based approaches have been at the forefront of developing novel and effective chemical therapeutics against PIM in preclinical and clinical settings, and none have yet received approval for cancer treatment. The stability of PIM isoforms is maintained by PIM kinase activity, which leads to resistance against PIM inhibitors and chemotherapy; thus, to overcome such effects, PIM proteolysis targeting chimeras (PROTACs) are now being developed that specifically degrade PIM proteins. In this review, we recapitulate an overview of the oncogenic functions of PIM kinases, their structure, function, and crucial signaling network in different types of cancer, and the potential of pharmacological small-molecule inhibitors. Further, our comprehensive review also provides valuable insights for developing novel antitumor drugs that specifically target PIM kinases in the future. In conclusion, we provide insights into the benefits of degrading PIM kinases as opposed to blocking their catalytic activity to address the oncogenic potential of PIM kinases.

Involvement of cardiac glycosides targeting Na/K-ATPase in their inhibitory effects on c-Myc expression via its transcription, translation and proteasomal degradation

Cardiac glycosides (CGs) have been used for decades to treat heart failure and arrhythmic diseases. Recent non-clinical and epidemiological findings have suggested that CGs exhibit anti-tumor activities. Therefore, CGs may be repositioned as drugs for the treatment of cancer. A detailed understanding of the anti-cancer mechanisms of CGs is essential for their application to the treatment of targetable cancer types. To elucidate the factors associated with the anti-tumor effects of CGs, we performed transcriptome profiling on human multiple myeloma AMO1 cells treated with periplocin, one of the CGs. Periplocin significantly down-regulated the transcription of MYC (c-Myc), a well-established oncogene. Periplocin also suppressed c-Myc expression at the protein levels. This repression of c-Myc was also observed in several cell lines. To identify target proteins for the inhibition of c-Myc, we generated CG-resistant (C9) cells using a sustained treatment with digoxin. We confirmed that C9 cells acquired resistance to the inhibition of c-Myc expression and cell proliferation by CGs. Moreover, the sequencing of genomic DNA in C9 cells revealed the mutation of D128N in α1-Na/K-ATPase, indicating the target protein. These results suggest that CGs suppress c-Myc expression in cancer cells via α1-Na/K-ATPase, which provides further support for the anti-tumor activities of CGs.

PIM Kinase Inhibitors as Novel Promising Therapeutic Scaffolds in Cancer Therapy

Cancer involves the uncontrolled, abnormal growth of cells and affects other tissues. Kinase has an impact on proliferating the cells and causing cancer. For the purpose of treating cancer, PIM kinase is a potential target. The pro-viral Integration site for moloney murine leukaemia virus (PIM) kinases is responsible for the tumorigenesis, by phosphorylating the proteins that control the cell cycle and cell proliferation. PIM-1, PIM-2, and PIM-3 are the three distinct isoforms of PIM kinases. The JAK/STAT pathway is essential for controlling how PIM genes are expressed. PIM kinase is also linked withPI3K/AKT/mTOR pathway in various types of cancers. The overexpression of PIM kinase will cause cancer. Currently, there are significant efforts being made in medication design and development to target its inhibition. A few small chemical inhibitors (E.g., SGI-1776, AZD1208, LGH447) that specifically target the PIM proteins' adenosine triphosphate (ATP)-binding domain have been identified. PIM kinase antagonists have a remarkable effect on different types of cancer. Despite conducting clinical trials on SGI-1776, the first PIM inhibitory agent, was prematurely withdrawn, making it unable to generate concept evidence. On the other hand, in recent years, it has aided in hastening the identification of multiple new PIM inhibitors. Cyanopyridines and Pyrazolo[1,5-a]pyrimidinecan act as potent PIM kinase inhibitors for cancer therapy. We explore the involvement of oncogenic transcription factor c-Mycandmi-RNA in relation to PIM kinase. In this article, we highlight the oncogenic effects, and structural insights into PIM kinase inhibitors for the treatment of cancer.

Discovery of PIM-1 kinase inhibitors based on the 2,5-disubstituted 1,3,4-oxadiazole scaffold against prostate cancer: Design, synthesis, in vitro and in vivo cytotoxicity investigation

PIM-1 kinases play an established role in prostate cancer development and progression. This research work tackles the design and synthesis of new PIM-1 kinase targeting 2,5-disubstituted-1,3,4-oxadiazoles 10a-g&11a-f, and investigation thereof as potential anti-cancer agents through in vitro cytotoxicity assay followed by in vivo studies along with exploration of this chemotype's plausible mechanism of action. In vitro cytotoxicity experiments have disclosed 10f as the most potent derivative against PC-3 cells (IC₅₀ = 16 nM) compared to the reference drug Staurosporine (IC₅₀ = 0.36 μM), also eliciting good cytotoxicity against HepG2 and MCF-7 cells (IC₅₀ = 0.13 and 5.37 μM, respectively). Investigating PIM-1 kinase inhibitory activity of compound 10f revealed an IC₅₀ of 17 nM paralleled to that of Staurosporine (IC₅₀ = 16.7 nM). Furthermore, compound 10f displayed an antioxidant activity eliciting a DPPH inhibition ratio of 94% as compared to Trolox (96%). Further investigation demonstrated that 10f induced apoptosis in treated PC-3 cells by 43.2-fold (19.44%) compared to 0.45% in control. 10f also disrupted the PC-3 cell cycle by increasing the cell population at the PreG1-phase by 19.29-fold while decreasing the G2/M-phase by 0.56-fold compared to control. Moreover, 10f affected a downregulation of JAK2, STAT3 and Bcl-2 and upregulation of caspases 3, 8 and 9 levels that activated the caspase-dependent apoptosis. Finally, in vivo 10f-treatment caused a significant increase in tumor inhibition by 64.2% compared to 44.5% in Staurosporine treatment of the PC-3 xenograft mouse model. Additionally, it improved the hematological, biochemical parameters, and histopathological examinations compared to control untreated animals. Finally, docking of 10f with the ATP-binding site of PIM-1 kinase demonstrated good recognition of and effective binding to the active site. In conclusion, compound 10f represents a promising lead compound that merits further future optimization for controlling prostate cancer.

Targeting PIM Kinases to Improve the Efficacy of Immunotherapy

The Proviral Integration site for Moloney murine leukemia virus (PIM) kinases is a family of serine/threonine kinases that regulates numerous signaling networks that promote cell growth, proliferation, and survival. PIM kinases are commonly upregulated in both solid tumors and hematological malignancies. Recent studies have demonstrated that PIM facilitates immune evasion in cancer by promoting an immunosuppressive tumor microenvironment that suppresses the innate anti-tumor response. The role of PIM in immune evasion has sparked interest in examining the effect of PIM inhibition in combination with immunotherapy. This review focuses on the role of PIM kinases in regulating immune cell populations, how PIM modulates the immune tumor microenvironment to promote immune evasion, and how PIM inhibitors may be used to enhance the efficacy of immunotherapy.

PIM1-Induced Cytoplasmic Expression of RBMY Mediates Hepatocellular Carcinoma Metastasis

BACKGROUND & AIMS

Metastasis indicates a grave prognosis in patients with hepatocellular carcinoma (HCC). Our previous studies showed that RNA binding motif protein Y-linked (RBMY) is potentially a biomarker for poor survival in HCC patients, but its role in metastasis is largely unclear.

METHODS

A total of 308 male patients with primary HCC were enrolled. RBMY expression was traced longitudinally by immunostaining from the manifestation of a primary HCC tumor to the formation of a distant metastasis, and its upstream regulators were screened with a protein microarray. A series of metastasis assays in mouse models and HCC cell lines were performed to explore new functional insights into RBMY.

RESULTS

Cytoplasmic expression of RBMY was associated with rapid distant metastasis (approximately 1 year after resection) and had a predictive power of 82.4% for HCC metastasis. RBMY conferred high migratory and invasive potential upon phosphorylation by the provirus integration in Moloney 1 (PIM1) kinase. Binding of PIM1 to RBMY caused mutual stabilization and massive translocation of RBMY from nuclei to mitochondria, thereby preventing mitochondrial apoptosis and augmenting mitochondrial generation of adenosine triphosphate/reactive oxygen species to enhance cell motility. Depletion of RBMY suppressed Snail1/zinc finger E-box binding homeobox transcription factor 1-mediated epithelial-mesenchymal transition and dynamin-related protein 1-dependent mitochondrial fission. Inactivation and knockout of PIM1 down-regulated the expression of RBMY. In nude mice, cytoplasmic RBMY promoted liver-to-lung metastasis by increasing epithelial-mesenchymal transition, mitochondrial proliferation, and mitochondrial fission, whereas nuclear-restricted RBMY impeded the mitochondrial switch and failed to induce lung metastasis.

CONCLUSIONS

This study showed the regulation of HCC metastasis by PIM1-driven cytoplasmic expression of RBMY and suggested a novel therapeutic target for attenuating metastasis.

Vertebrate Cell Differentiation, Evolution, and Diseases: The Vertebrate-Specific Developmental Potential Guardians VENTX/NANOG and POU5/OCT4 Enter the Stage

During vertebrate development, embryonic cells pass through a continuum of transitory pluripotent states that precede multi-lineage commitment and morphogenesis. Such states are referred to as “refractory/naïve” and “competent/formative” pluripotency. The molecular mechanisms maintaining refractory pluripotency or driving the transition to competent pluripotency, as well as the cues regulating multi-lineage commitment, are evolutionarily conserved. Vertebrate-specific “Developmental Potential Guardians” (vsDPGs; i.e., VENTX/NANOG, POU5/OCT4), together with MEK1 (MAP2K1), coordinate the pluripotency continuum, competence for multi-lineage commitment and morphogenesis in vivo. During neurulation, vsDPGs empower ectodermal cells of the neuro-epithelial border (NEB) with multipotency and ectomesenchyme potential through an “endogenous reprogramming” process, giving rise to the neural crest cells (NCCs). Furthermore, vsDPGs are expressed in undifferentiated-bipotent neuro-mesodermal progenitor cells (NMPs), which participate in posterior axis elongation and growth. Finally, vsDPGs are involved in carcinogenesis, whereby they confer selective advantage to cancer stem cells (CSCs) and therapeutic resistance. Intriguingly, the heterogenous distribution of vsDPGs in these cell types impact on cellular potential and features. Here, we summarize the findings about the role of vsDPGs during vertebrate development and their selective advantage in evolution. Our aim to present a holistic view regarding vsDPGs as facilitators of both cell plasticity/adaptability and morphological innovation/variation. Moreover, vsDPGs may also be at the heart of carcinogenesis by allowing malignant cells to escape from physiological constraints and surveillance mechanisms.

Discovery of novel natural products as dual MNK/PIM inhibitors for acute myeloid leukemia treatment: Pharmacophore modeling, molecular docking, and molecular dynamics studies

MNK-2 and PIM-2 kinases play an indispensable role in cell proliferation signaling pathways linked to tyrosine kinase inhibitors resistance. In this study, pharmacophore modeling studies have been conducted on the co-crystalized ligands of MNK-2 and PIM-2 enzyme crystal structures to determine the essential features required for the identification of potential dual inhibitors. The obtained pharmacophore features were then screened against a library of 270,540 natural products from the ZINC database. The matched natural molecules were docked into the binding sites of MNK-2 and PIM-2 enzymes. The compounds with high docking scores with the two enzymes were further subjected to MM-GBSA calculations and ADME prediction. This led to the identification of compound 1 (ZINC000085569211), compound 2 (ZINC000085569178), and compound 3 (ZINC000085569190), with better docking scores compared to the reference co-crystallized ligands of MNK-2 and PIM-2. Moreover, compounds 1‒3 displayed better MM-GBSA binding free energies compared to the reference ligands. Finally, molecular dynamics (MD) study was used to assess the interaction stability of the compounds with MNK-2. To this end, compounds 1 and 3 bound strongly to the target during the whole period of MD simulation. The findings of the current study may further help the researchers in the discovery of novel molecules against MNK-2 and PIM-2.

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.

PIM1 phosphorylation of the androgen receptor and 14-3-3 ζ regulates gene transcription in prostate cancer

PIM1 is a serine/threonine kinase over-expressed in prostate cancer. We have previously shown that PIM1 phosphorylates the androgen receptor (AR), the primary therapeutic target in prostate cancer, at serine 213 (pS213), which alters expression of select AR target genes. Therefore, we sought to investigate the mechanism whereby PIM1 phosphorylation of AR alters its transcriptional activity. We previously identified the AR co-activator, 14-3-3 ζ, as an endogenous PIM1 substrate in LNCaP cells. Here, we show that PIM1 phosphorylation of AR and 14-3-3 ζ coordinates their interaction, and that they extensively occupy the same sites on chromatin in an AR-dependent manner. Their occupancy at a number of genes involved in cell migration and invasion results in a PIM1-dependent increase in the expression of these genes. We also use rapid immunoprecipitation and mass spectrometry of endogenous proteins on chromatin (RIME), to find that select AR co-regulators, such as hnRNPK and TRIM28, interact with both AR and 14-3-3 ζ in PIM1 over-expressing cells. We conclude that PIM1 phosphorylation of AR and 14-3-3 ζ coordinates their interaction, which in turn recruits additional co-regulatory proteins to alter AR transcriptional activity.

Pim-2 kinase inhibits inflammation by suppressing the mTORC1 pathway in atherosclerosis

Background: Inflammatory immunity theory has raised considerable concern in the pathogenesis of atherosclerosis. Proviral integration site of murine 2 (Pim-2) kinases functions in apoptosis pathways and the anti-inflammatory response. Here, we investigated whether Pim-2 kinase inhibits atherosclerotic inflammation by suppressing the mTORC1 pathway.

Methods: An atherosclerosis animal model was established by feeding ApoE ^-/- mice a high-fat diet. THP-1-derived macrophages were subjected to ox-LDL (50 μg/ml, 24h) conditions in vitro to mimic the in vivo conditions.

Result: The protein expression of Pim-2 was upregulated in ox-LDL-treated THP-1-derived macrophages and an atherosclerotic mouse model. Additionally, ox-LDL upregulated the protein expression of p-mTOR, p-S6K1 and p-4EBP1, intracellular lipid droplets, free cholesterol and cholesterylester and the mRNA expression of inflammatory cytokines, including IL-6, MCP-1, TLR-4 and TNF-α, in THP-1-derived macrophages. Functionally, overexpressed Pim-2 (Pim-2 OE) attenuated atherosclerotic inflammation associated with the mTORC1 signaling pathway in vitro and in vivo, whereas knocked down Pim-2 (Pim-2 KD) markedly promoted atherosclerotic inflammation associated with upregulation of the mTORC1 signaling pathway. The plaque areas and lesions in the whole aorta and aortic root sections were alleviated in ApoE ^-/- mice with Pim-2 OE, but aggravated by Pim-2 KD. Additionally, an mTOR agonist (MHY1485) counteracted the anti-inflammatory effect of Pim-2 in ox-LDL-treated THP-1-derived macrophages after Pim-2 OE, whereas rapamycin rescued atherosclerotic inflammation in ox-LDL-treated THP-1-derived macrophages after Pim-2 KD. Furthermore, si-mTOR and si-Raptor alleviated the atherosclerotic proinflammatory effect in ox-LDL-treated THP-1-derived macrophages in a the background of Pim-2 KD.

Conclusions:These results indicated that Pim-2 kinase inhibits atherosclerotic inflammation by suppressing the mTORC1 pathway.

Therapeutic targeting of PIM KINASE signaling in cancer therapy: Structural and clinical prospects

BACKGROUND

PIM kinases are well-studied drug targets for cancer, belonging to Serine/Threonine kinases family. They are the downstream target of various signaling pathways, and their up/down-regulation affects various physiological processes. PIM family comprises three isoforms, namely, PIM-1, PIM-2, and PIM-3, on alternative initiation of translation and they have different levels of expression in different types of cancers. Its structure shows a unique ATP-binding site in the hinge region which makes it unique among other kinases.

SCOPE OF REVIEW

PIM kinases are widely reported in hematological malignancies along with prostate and breast cancers. Currently, many drugs are used as inhibitors of PIM kinases. In this review, we highlighted the physiological significance of PIM kinases in the context of disease progression and therapeutic targeting. We comprehensively reviewed the PIM kinases in terms of their expression and regulation of different physiological roles. We further predicted functional partners of PIM kinases to elucidate their role in the cellular physiology of different cancer and mapped their interaction network.

MAJOR CONCLUSIONS

A deeper mechanistic insight into the PIM signaling involved in regulating different cellular processes, including transcription, apoptosis, cell cycle regulation, cell proliferation, cell migration and senescence, is provided. Furthermore, structural features of PIM have been dissected to understand the mechanism of inhibition and subsequent implication of designed inhibitors towards therapeutic management of prostate, breast and other cancers.

GENERAL SIGNIFICANCE

Being a potential drug target for cancer therapy, available drugs and PIM inhibitors at different stages of clinical trials are discussed in detail.

Protein kinase PIM2: A simple PIM family kinase with complex functions in cancer metabolism and therapeutics

PIM2 (proviral integration site for Moloney murine leukemia virus 2) kinase plays an important role as an oncogene in multiple cancers, such as leukemia, liver, lung, myeloma, prostate and breast cancers. PIM2 is largely expressed in both leukemia and solid tumors, and it promotes the transcriptional activation of genes involved in cell survival, cell proliferation, and cell-cycle progression. Many tumorigenic signaling molecules have been identified as substrates for PIM2 kinase, and a variety of inhibitors have been developed for its kinase activity, including SMI-4a, SMI-16a, SGI-1776, JP11646 and DHPCC-9. Here, we summarize the signaling pathways involved in PIM2 kinase regulation and PIM2 mechanisms in various neoplastic diseases. We also discuss the current status and future perspectives for the development of PIM2 kinase inhibitors to combat human cancer, and PIM2 will become a therapeutic target in cancers in the future.

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.

Prostate carcinogenesis: inflammatory storms

Prostate cancer is a major cause of cancer morbidity and mortality. Intra-prostatic inflammation is a risk factor for prostate carcinogenesis, with diet, chemical injury and an altered microbiome being causally implicated. Intra-prostatic inflammatory cell recruitment and expansion can ultimately promote DNA double-strand breaks and androgen receptor activation in prostate epithelial cells. The activation of the senescence-associated secretory phenotype fuels further 'inflammatory storms', with free radicals leading to further DNA damage. This drives the overexpression of DNA repair and tumour suppressor genes, rendering these genes susceptible to mutagenic insults, with carcinogenesis accelerated by germline DNA repair gene defects. We provide updates on recent advances in elucidating prostate carcinogenesis and explore novel therapeutic and prevention strategies harnessing these discoveries.

A serine/threonine protein PIM kinase as a biomarker of cancer and a target for anti-tumor therapy

The PIM Kinases belong to the family of a proto-oncogene that essentially phosphorylates the serine/threonine residues of the target proteins. They are primarily categorized into three types PIM-1, PIM-2, PIM-3 which plays an indispensable regulatory role in signal transduction cascades, by promoting cell survival, proliferation, and drug resistance. These kinases are overexpressed in several solid as well as hematopoietic tumors which supports in vitro and in vivo malignant cell growth along with survival by regulating cell cycle and inhibiting apoptosis. They lack regulatory domain which makes them constitutively active once transcribed. PIM kinases usually appear to be important downstream effectors of oncoproteins which overexpresses and helps in mediating drug resistance to available agents, such as rapamycin. Structural studies of PIM kinases revealed that they have unique hinge regions where two Proline resides and makes ATP binding unique, by offering a target for an increasing number of potent PIM kinase inhibitors. Preclinical studies of those inhibitory compounds in various cancers indicate that these novel agents show promising activity and some of them currently being under examination. In this review, we have outlined PIM kinases molecular mechanism and signaling pathways along with matriculation in various cancer and list of inhibitors often used.

Unique and redundant roles of SOX2 and SOX17 in regulating the germ cell tumor fate

Embryonal carcinomas (ECs) and seminomas are testicular germ cell tumors. ECs display expression of SOX2, while seminomas display expression of SOX17. In somatic differentiation, SOX17 drives endodermal cell fate. However, seminomas lack expression of endoderm markers, but show features of pluripotency. Here, we use chromatin immunoprecipitation sequencing to report and compare the binding pattern of SOX17 in seminoma-like TCam-2 cells to SOX17 in somatic cells and SOX2 in EC-like 2102EP cells. In seminoma-like cells, SOX17 was detected at canonical (SOX2/OCT4), compressed (SOX17/OCT4) and noncomposite SOX motifs. SOX17 regulates TFAP2C, PRDM1 and PRDM14, thereby maintaining latent pluripotency and suppressing somatic differentiation. In contrast, in somatic cells canonical motifs are rarely bound by SOX17. In sum, only 12% of SOX17-binding sites overlap in seminoma-like and somatic cells. This illustrates that binding site choice is highly dynamic and cell type specific. Deletion of SOX17 in seminoma-like cells resulted in loss of pluripotency, marked by a reduction of OCT4 protein level and loss of alkaline phosphatase activity. Furthermore, we found that in EC-like cells SOX2 regulates pluripotency-associated genes, most likely by partnering with OCT4. In conclusion, SOX17 (in seminomas) functionally replaces SOX2 (in ECs) to maintain expression of the pluripotency cluster.

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.

Analysis of Genomic Alteration in Primary Central Nervous System Lymphoma and the Expression of Some Related Genes

Primary central nervous system lymphoma (PCNSL) is a rare and special type of non-Hodgkin lymphoma. The treatment of PCNSL is comprehensive, combining surgery, radiotherapy, and chemotherapy. However, the outcome is poor because of its high invasiveness and rate of recurrence. We analyzed 22 cases of PCNSL using next-generation sequencing (NGS) to detect 64 candidate genes. We used immunohistochemical methods to analyze gene expression in 57 PCNSL samples. NGS showed that recurrent mutations in KMT2D and CD79B, components of the NF-κB pathway, accounted for 65% of total mutations in PCNSL samples. The most frequent mutated gene was PIM1 (77.27%, 17/22), followed by MYD88 (63.64%, 14/22), CD79B (69.09%, 13/22), and KMT2D (50.00%, 11/22). Mutations of the CD79B gene were associated with an inferior progression-free survival (PFS), and GNA13 gene mutations were associated with a shorter PFS and overall survival (OS) in PCNSL patients (P < .05). PIM1 and MYD88 were highly expressed in PCNSL patients and were related to their OS time. MYD88 overexpression might be an independent and poor prognostic predictor of OS time. In summary, we identified highly recurrent genetic lesions in CD79B and KMT2D, components of the NF-κB pathway, in PCNSL and validated the expression of PIM1 and MYD88 related to poor survival, thereby providing novel insights into the pathogenesis and precision medicine of PCNSL.

PIM Kinase as an Executional Target in Cancer

PIM (proviral integration site for moloney murine leukemia virus) kinase plays a key role as an oncogene in various cancers including myeloma, leukemia, prostate and breast cancers. The aberrant expression and/or activation of PIM kinases in various cancers follow an isoform-specific pattern. While PIM1 is predominantly expressed in hematological and solid tumors, PIM2 and PIM3 are largely expressed in leukemia and solid tumors, respectively. All of PIM kinases cause transcriptional activation of genes involved in cell survival and cell cycle progression in cancer. A variety of pro-tumorigenic signaling molecules, such as MYC, p21^Cip1/Waf1/p27^kip1, CDC25, Notch1 and BAD have been identified as the downstream targets of PIM kinases. So far, three kinds of adenosine triphosphate-competitive PIM inhibitors, SGI-1776, AZD1208, and LGH447 have been in clinical trials for the treatment of acute myelogenous leukemia, prostate cancer, lymphoma, or multiple myeloma. This review sheds light on the signaling pathways involved in the PIM kinase regulation and current status of developing PIM kinase inhibitors as clinical success in combating human cancer.

Conservation of epigenetic regulation by the MLL3/4 tumour suppressor in planarian pluripotent stem cells

Currently, little is known about the evolution of epigenetic regulation in animal stem cells. Here we demonstrate, using the planarian stem cell system to investigate the role of the COMPASS family of MLL3/4 histone methyltransferases that their function as tumor suppressors in mammalian stem cells is conserved over a long evolutionary distance. To investigate the potential conservation of a genome-wide epigenetic regulatory program in animal stem cells, we assess the effects of Mll3/4 loss of function by performing RNA-seq and ChIP-seq on the G2/M planarian stem cell population, part of which contributes to the formation of outgrowths. We find many oncogenes and tumor suppressors among the affected genes that are likely candidates for mediating MLL3/4 tumor suppression function. Our work demonstrates conservation of an important epigenetic regulatory program in animals and highlights the utility of the planarian model system for studying epigenetic regulation.

Highly Selective Red-Emitting Fluorescent Probe for Imaging Cancer Cells in Situ by Targeting Pim-1 Kinase

Based on the fact that enzyme-targeting probes are highly sensitive and selective, a novel red-emitting probe (NB-BF) for Pim-1 kinase including three parts, fluorophore (NB), linker, and inhibitor (BF), has been designed for cancer optical imaging. In its free state, NB-BF is folded and the fluorescence quenched by PET between fluorophore and inhibitor both in PBS buffer and in normal cells. Significantly, it emitted strong red fluorescence in Pim-1 overexpressed cancer cells. The specificity of NB-BF for Pim-1 kinase was directly demonstrated by gene silencing analysis. Furthermore, it is the first time to know where Pim-1 kinase mainly distributes at mitochondria with Pearson's correlation factor (R_r) of 0.965 and to provide a fluorescent tool to verify the function of the Pim-1 kinase. More importantly, NB-BF was applied in tissue imaging and preferentially labeled tumors in vivo.

Coordinated downregulation of Spinophilin and the catalytic subunits of PP1, PPP1CA/B/C, contributes to a worse prognosis in lung cancer

The scaffold protein Spinophilin (Spinophilin, PPP1R9B) is one of the regulatory subunits of phosphatase-1 (PP1), directing it to distinct subcellular locations and targets. The loss of Spinophilin reduces PP1 targeting to pRb, thereby maintaining higher levels of phosphorylated pRb. Spinophilin is absent or reduced in approximately 40% of human lung tumors, correlating with the malignant grade. However, little is known about the relevance of the coordinated activity or presence of Spinophilin and its reported catalytic partners in the prognosis of lung cancer. In the present work, we show that the downregulation of Spinophilin, either by protein or mRNA, is related to a worse prognosis in lung tumors. This effect is more relevant in squamous cell carcinoma, SCC, than in adenocarcinoma. Downregulation of Spinophilin is related to a decrease in the levels of its partners PPP1CA/B/C, the catalytic subunits of PP1. A decrease in these subunits is also related to prognosis in SCC and, in combination with a decrease in Spinophilin, are markers of a poor prognosis in these tumors. The analysis of the genes that correlate to Spinophilin in lung tumors showed clear enrichment in ATP biosynthesis and protein degradation GO pathways. The analysis of the response to several common and pathway-related drugs indicates a direct correlation between the Spinophilin/PPP1Cs ratio and the response to oxaliplatin and bortezomib. This finding indicates that this ratio may be a good predictive biomarker for the activity of the drugs in these tumors with a poor prognosis.

PIM activity in tumours: A key node of therapy resistance

The PIM kinases are proto-oncogenes which have been shown to facilitate cell survival and proliferation to drive malignancy and resistance post-therapy. They are able to suppress cell death signals, sustain PI3K/AKT/mTORC1 pathway activity and regulate the MYC oncogenic program. Recent work has revealed PIM kinase essentiality for advanced tumour maintenance and described tumour sensitivity to small molecule inhibitors targeting PIM kinase in multiple malignancies.

The cargo protein MAP17 (PDZK1IP1) regulates the immune microenvironment

Inflammation is a complex defensive response activated after various harmful stimuli allowing the clearance of damaged cells and initiating healing and regenerative processes. Chronic, or pathological, inflammation is also one of the causes of neoplastic transformation and cancer development. MAP17 is a cargo protein that transports membrane proteins from the endoplasmic reticulum. Therefore, its overexpression may be linked to an excess of membrane proteins that may be recognized as an unwanted signal, triggering local inflammation. Therefore, we analyzed whether its overexpression is related to an inflammatory phenotype. In this work, we found a correlation between MAP17 expression and inflammatory phenotype in tumors and in other inflammatory diseases such as Crohn's disease, Barrett's esophagus, COPD or psoriasis. MAP17 expression correlated also with the markers of inflammation HLAs, BBS10, HERC2, ADNP and PYCARD. Furthermore, we found that MAP17 expression directly regulates NFAT2 and IL-6 activation, inducing the differentiation of monocytes to dendritic cells and suggesting a causal role of MAP17 in inflammation. Immunohistochemistry confirms local inflammation, mainly CD45⁺ cells, at the site of expression of MAP17, at least in tumors, Crohn's and psoriasis. Therefore, our data indicates that the overexpression of the protein MAP17 plays important role in diseases involving chronic inflammation.