Pim1 kinase synergizes with c-MYC to induce advanced prostate carcinoma

Myc family proteins: Molecular drivers of tumorigenesis and resistance in neuroendocrine tumors

Neuroendocrine cancers are a diverse and poorly understood collection of malignancies derived from neuroendocrine cells throughout the body. These cancers uniquely exhibit properties of both the nervous and endocrine systems. Only a limited number of genetic driver mutations have been identified in neuroendocrine cancers, however the mechanisms of how these genetic aberrations alter tumor biology remain elusive. Recent studies have implicated the MYC family of transcription factors as important oncogenic factors in neuroendocrine tumors. We take a systematic approach to understand the roles of the MYC family (c-MYC, n-MYC, l-MYC) in the tumorigenesis of neuroendocrine cancers of the lung, GI tract, pancreas, kidney, prostate, pediatric neuroblastoma, and adrenal glands. Reflecting the complexity of neuroendocrine cancers, we highlight the roles of the MYC family in deregulating the cell cycle and transcriptional networks, invoking cellular plasticity, affecting proliferation capacity, aiding in chromatin remodeling, angiogenesis, metabolic changes, and resistance mechanisms. Depicting the diversity of neuroendocrine cancers, we suggest new approaches in understanding the underlying tumorigenic processes of neuroendocrine cancers from the perspective of MYC.

Inhibition of PIM Kinase in Tumor-Associated Macrophages Suppresses Inflammasome Activation and Sensitizes Prostate Cancer to Immunotherapy

Immune checkpoint inhibitors (ICI) have changed the treatment paradigm for many cancers but have not shown benefit in prostate cancer. Chronic inflammation contributes to the immunosuppressive prostate tumor microenvironment and is associated with poor response to ICIs. The primary source of inflammatory cytokine production is the inflammasome. In this study, we identify the proviral integration site for Moloney murine leukemia virus (PIM) kinases as regulators of inflammasome activation in tumor-associated macrophages (TAM). The analysis of clinical data from a cohort of patients with treatment-naïve, hormone-responsive prostate cancer revealed that tumors from patients with high PIM1/2/3 displayed an immunosuppressive tumor microenvironment characterized by high inflammation and a high density of repressive immune cells, most notably TAMs. Macrophage-specific knockout of PIM reduced tumor growth in syngeneic models of prostate cancer. Transcriptional analyses indicated 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 prostate cancer tumors to ICIs by increasing tumor suppressive TAMs and increasing the activation of cytotoxic T cells. Our data implicate macrophage PIM as a driver of inflammation that limits ICI potency and provide preclinical evidence that PIM inhibitors are an effective strategy to improve the ICI efficacy in prostate cancer.

PIM kinase inhibition counters resistance to radiotherapy and chemotherapy in human prostate cancer

PURPOSE

PIM kinases are associated with treatment resistance and poor prognosis in prostate cancer through roles in DNA damage response, cellular metabolism, proliferation, and survival. We hypothesized PIM inhibition addresses treatment resistance to radiotherapy and docetaxel in prostate cancer.

METHODS

PIM inhibition in prostate cancer cell lines was examined by phosphorylated H2AX and colony formations assays. In normal and castrated mice with prostate tumor xenografts, tumor growth was monitored with daily oral PIM inhibition +/- fractionated radiotherapy (RT) or docetaxel. Radiotherapy was given 30 Gy in 15 treatments, mimicking clinical conventional daily treatment over 3 weeks in a translational murine model system.

RESULTS

PIM inhibition decreased radiotherapy-induced DNA-damage repair and decreased cell proliferation and survival. In mice, PIM inhibition increased the efficacy of both radiation and docetaxel to reduce tumor size in hormone-dependent and -independent xenografts. Xenografts showed altered gene expression changes, including downregulation of ribosomal pathways and upregulation of cardiomyocyte signaling pathways, due to PIM inhibition as analyzed by RNA-Seq. Immunostaining of multiple proteins, including COX-2 and MDM2, was altered by PIM inhibition.

CONCLUSIONS

PIM inhibition addresses treatment resistance to docetaxel and radiotherapy in multiple prostate cancer models. Our data provide a strong rationale for testing PIM inhibitors in combination with standard therapies for treatment-resistant high-risk localized or metastatic prostate cancer in clinical trials.

Unravelling the potency of the 4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile scaffold with S-arylamide hybrids as PIM-1 kinase inhibitors: synthesis, biological activity and in silico studies

PIM-1 is a type of serine/threonine kinase that plays a crucial role in controlling several vital processes, including proliferation and apoptosis. New synthetic S-amide tetrahydropyrimidinone derivatives were designed and synthesized as PIM-1 inhibitors with potential anticancer activity. Several biochemical assays were performed for anticancer assessment, including PIM-1 inhibitory assays, MTT, apoptosis and cell cycle, gene expression analysis, c-MYC analysis, and ATPase inhibitory assays. Compounds (8c, 8d, 8g, 8h, 8k, and 8l) exhibited strong in vitro broad antiproliferative activity against MCF-7, DU-145, and PC-3, with a relatively higher SI index suggesting minimal cytotoxicity to normal cells. Furthermore, these compounds induced mixed late apoptosis and necrosis with cell cycle arrest at the G2/M phase. Moreover, compounds 8b, 8f, 8g, 8k, and 8l showed potent inhibitory action against PIM-1 kinase, with corresponding IC50 values of 660, 909, 373, 518, and 501 nM. In silico prediction studies of physiochemical properties, molecular dynamics, and induced fit docking studies were performed for these compounds to explain their potent biological activity. In conclusion, new pyrimidinone compounds (8c, 8d, 8g, 8h, 8k, and 8l) exhibit potential PIM-1 inhibitory activity and can be used as promising scaffolds for further optimization of new leads with selective PIM-inhibitors and anticancer activity.

Role of guanylate-binding protein 1 in the proliferation of invasive lung adenocarcinoma cells

Background

Guanylate-binding protein 1 (GBP1) is involved in the malignant progression of lung adenocarcinoma, particularly in the acquisition of invasive potential. However, its role in tumor proliferation and therapeutic viability in invasive lung adenocarcinomas remains unclear.

Methods

This study included 99 patients with invasive lung adenocarcinoma, excluding those with non-invasive lepidic components, who had undergone complete pulmonary resection. Immunohistochemical staining was performed to examine the presence of GBP1, and its prognostic significance was assessed using uni- and multi-variable Cox regression analyses. Additionally, the expression levels of GBP1 gene and protein levels were evaluated in lung adenocarcinoma cell lines (PC-9, A549, NCI-H322, NCI-H441, NCI-H820, and ABC-1), and its proliferative role in these cell lines was analyzed using specific inhibitors targeting GBP1.

Results

GBP1 expression was detected in 45 (45.5%) patients. The 5-year overall survival rates for GBP1-positive and -negative patients were 66.0% (95% confidence interval (CI): 46.3-80.0%) and 85.7% (95% CI: 72.0-93.0%), respectively (P = 0.029). The multivariable analysis demonstrated that GBP1 positivity was an independent factor for poor overall survival (hazard ratio [HR] = 2.52 [95% CI: 1.02-6.22], P = 0.045). GBP1 gene and protein were markedly expressed in NCI-H820 than in NCI-H322 and ABC-1. The inhibitor targeting GBP1 significantly suppressed the growth of NCI-H820 but not that of NCI-H322 or ABC-1.

Conclusions

GBP1 is a prognostic factor that may be involved in the proliferation of invasive lung adenocarcinoma, suggesting that inhibiting GBP1 activity may be a promising therapeutic approach for lung adenocarcinoma patients expressing GBP1.

PROTACs as Therapeutic Modalities for Drug Discovery in Castration-Resistant Prostate Cancer

Castration-resistant prostate cancer (CRPC) presents significant challenges in clinical management due to its resistance to conventional androgen receptor (AR)-targeting therapies. The advent of proteolysis targeting chimeras (PROTACs) has revolutionized cancer therapy by enabling the targeted degradation of key molecular players implicated in CRPC progression. In this review we discuss the developments of PROTACs for CRPC treatment, focusing on AR and other CRPC-associated regulators. We provide an overview of the strategic trends in AR PROTAC development from the aspect of targeting site selection and preclinical antitumor evaluation, as well as updates on AR degraders in clinical applications. Additionally, we briefly address the current status of selective AR degrader development. Furthermore, we review new developments in PROTACs as potential CRPC treatment paradigms, highlighting those targeting chromatin modulators BRD4, EZH2, and SWI/SNF; transcription regulator SMAD3; and kinases CDK9 and PIM1. Given the molecular targets shared between CRPC and neuroendocrine prostate cancer (NEPC), we also discuss the potential of PROTACs in addressing NEPC.

Construction of molecular subtype and prognostic model for gastric cancer based on nucleus-encoded mitochondrial genes

Gastric cancer (GC) is a common digestive system cancer, characterized by a significant mortality rate. Mitochondria is an indispensable organelle in eukaryotic cells. It was previously revealed that a series of nucleus-encoded mitochondrial genes (NMG) mutations and dysfunctions potentially contribute to the initiation and progression of GC. However, the correlation between NMG mutations and survival outcomes for GC patients is still unclear. In this study, NMG expression profile and clinical information in GC samples were collected from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Through consistent clustering and functional enrichment analysis, we have identified three NMG clusters and three gene clusters that are associated with patterns of immune cell infiltration. Prognostic genes were identified through Univariate Cox regression analysis. The principal component analysis was conducted to set up a scoring system. Subsequently, the Single‑cell RNA sequencing (scRNA-seq) data of GC patients and cancer cell drug sensitivity data were retrieved from the GEO database. Patients with high NMG scores exhibited increased microsatellite instability status and a heightened tumor mutation rate compared to those with low NMG scores. Survival analysis revealed that GC samples with high NMG scores could achieve a better prognosis. Additionally, These patients were observed to be more responsive to immunotherapy. Moreover, we delved into prognostic genes at the level of single cells, revealing that MRPL4 and MRPL37 exhibit high expression in epithelial cells, while TPM1 demonstrates high expression in tissue stem cells. Utilizing cancer cell drug sensitivity data from the Drug Sensitivity in Cancer (GDSC) database, we noted a heightened sensitivity to chemotherapy in the high NMG group. Furthermore, we discovered a significant enrichment of cuproptosis-related genes in clusters with high NMG scores. Consequently, employing the scoring system could facilitate the prediction of GC patients' sensitivity to cuproptosis-induced therapy. Our study confirmed the potency of this scoring system as a therapeutic response biomarker for gastric cancer, potentially informing clinical treatment strategies.

PIM1 kinase and its diverse substrate in solid tumors

The PIM kinase family, consisting of PIM1, PIM2, and PIM3, is a group of serine/threonine protein kinases crucial for cellular growth, immunoregulation, and oncogenesis. PIM1 kinase is often overexpressed in solid and hematopoietic malignancies, promoting cell survival, proliferation, migration, and senescence by activating key genes. In vitro and in vivo studies have established the oncogenic potential of PIM1 kinases. These kinases have been implicated in tumor progression, metastasis, and resistance to chemotherapy, underscoring their potential as a therapeutic target for cancer therapy. This review delves into the intricate molecular mechanisms through which PIM1 interacts with specific substrates in different tumor tissues, leading to diverse outcomes in various human cancers. Over the past decade, the inhibition of PIM1 in cancers has garnered significant attention as a potential standalone treatment. Various in vitro, in vivo, and early clinical trial data have provided support for this approach to varying extents. Novel compounds that inhibit PIM1 kinase have shown effectiveness and a favorable toxicity profile in preclinical studies. Several of these substances are now being studied in clinical trials due to their promising outcomes. This article provides a thorough examination of the PIM1 kinase pathways and the recent advancements in producing PIM1 kinase inhibitors for the treatment of cancer.

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.

Cooperativity of c-MYC with Krüppel-Like Factor 6 Splice Variant 1 induces phenotypic plasticity and promotes prostate cancer progression and metastasis

Metastasis remains a major cause of morbidity and mortality in men with prostate cancer, and the functional impact of the genetic alterations, alone or in combination, driving metastatic disease remains incompletely understood. The proto-oncogene c-MYC, commonly deregulated in prostate cancer. Transgenic expression of c-MYC is sufficient to drive the progression to prostatic intraepithelial neoplasia and ultimately to moderately differentiated localized primary tumors, however, c-MYC-driven tumors are unable to progress through the metastatic cascade, suggesting that a "second-hit" is necessary in the milieu of aberrant c-MYC-driven signaling. Here, we identified cooperativity between c-MYC and KLF6-SV1, an oncogenic splice variant of the KLF6 gene. Transgenic mice that co-expressed KLF6-SV1 and c-MYC developed progressive and metastatic prostate cancer with a histological and molecular phenotype like human prostate cancer. Silencing c-MYC expression significantly reduced tumor burden in these mice supporting the necessity for c-MYC in tumor maintenance. Unbiased global proteomic analysis of tumors from these mice revealed significantly enriched vimentin, a dedifferentiation and pro-metastatic marker, induced by KLF6-SV1. c-MYC-positive tumors were also significantly enriched for KLF6-SV1 in human prostate cancer specimens. Our findings provide evidence that KLF6-SV1 is an enhancer of c-MYC-driven prostate cancer progression and metastasis, and a correlated genetic event in human prostate cancer with potential translational significance.

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.

Characterizing prostate cancer risk through multi-ancestry genome-wide discovery of 187 novel risk variants

The transferability and clinical value of genetic risk scores (GRSs) across populations remain limited due to an imbalance in genetic studies across ancestrally diverse populations. Here we conducted a multi-ancestry genome-wide association study of 156,319 prostate cancer cases and 788,443 controls of European, African, Asian and Hispanic men, reflecting a 57% increase in the number of non-European cases over previous prostate cancer genome-wide association studies. We identified 187 novel risk variants for prostate cancer, increasing the total number of risk variants to 451. An externally replicated multi-ancestry GRS was associated with risk that ranged from 1.8 (per standard deviation) in African ancestry men to 2.2 in European ancestry men. The GRS was associated with a greater risk of aggressive versus non-aggressive disease in men of African ancestry (P = 0.03). Our study presents novel prostate cancer susceptibility loci and a GRS with effective risk stratification across ancestry groups.

Synthesis and Anticancer Activity of Novel Dual Inhibitors of Human Protein Kinases CK2 and PIM-1

CK2 and PIM-1 are serine/threonine kinases involved in the regulation of many essential processes, such as proliferation, differentiation, and apoptosis. Inhibition of CK2 and PIM-1 kinase activity has been shown to significantly reduce the viability of cancer cells by inducing apoptosis. A series of novel amino alcohol derivatives of parental DMAT were designed and synthesized as potent dual CK2/PIM-1 inhibitors. Concomitantly with the inhibition studies toward recombinant CK2 and PIM-1, the influence of the obtained compounds on the viability of three human carcinoma cell lines, i.e., acute lymphoblastic leukemia (CCRF-CEM), human chronic myelogenous leukemia (K-562), and breast cancer (MCF-7), as well as non-cancerous cells (Vero), was evaluated using an MTT assay. Induction of apoptosis and cell cycle progression after treatment with the most active compound and a lead compound were studied by flow-cytometry-based assay. Additionally, autophagy induction in K-562 cells and intracellular inhibition of CK2 and PIM-1 in all the tested cell lines were evaluated by qualitative/quantitative fluorescence-based assay and Western blot method, respectively. Among the newly developed inhibitors, 1,1,1-trifluoro-3-[(4,5,6,7-tetrabromo-1H-benzimidazol-2-yl)amino]propan-2-ol demonstrates the highest selectivity and the most prominent proapoptotic properties towards the studied cancer cells, especially towards acute lymphoblastic leukemia, in addition to inducing autophagy in K-562 cells.

PIM1 is a Poor Prognostic Factor for and Potential Therapeutic Target in Serous Carcinoma of the Endometrium

Serous carcinoma (SC) is an aggressive histologic type of endometrial carcinoma (EMC) with a poor prognosis. The development of novel therapeutics for SC is an important issue. PIM1 is a serine/threonine kinase involved in various cellular functions, such as cell cycle progression, apoptosis, and transcriptional activation via the phosphorylation of many target proteins, including MYC. PIM1 is overexpressed in several cancers and has been associated with treatment-resistance. We investigated the expression and function of PIM1 in EMC, particularly SC. Immunohistochemical analysis in 133 EMC cases [103 endometrioid carcinomas (EC) and 30 SC] revealed the significantly stronger expression of PIM1 in SC than in EC and significantly shorter survival of patients with overexpression of PIM1 in all EMC cases, as well as in only SC cases. A multivariate analysis identified overexpression of PIM1 as an independent prognostic factor. The knockdown of PIM1 by siRNA in the SC cell line, ARK1, decreased the expression of phosphorylated MYC and reduced proliferation, migration, and invasion. The PIM1 inhibitor, SGI-1776, reduced cell viability in SC cell lines (ARK1, ARK2, and SPAC1L) with IC50 between 1 and 5 µM. SGI-1776 also reduced the migration and invasion of ARK1 cells. Moreover, the oral administration of SGI-1776 significantly suppressed subcutaneous ARK1 xenograft tumor growth in nude mice without impairing health. These results indicate that PIM1 is involved in the acquisition of aggressiveness and suggest the potential of PIM1 as a novel therapeutic target and SGI-1776 as a therapeutic agent for SC.

When Just One Phosphate Is One Too Many: The Multifaceted Interplay between Myc and Kinases

Myc transcription factors are key regulators of many cellular processes, with Myc target genes crucially implicated in the management of cell proliferation and stem pluripotency, energy metabolism, protein synthesis, angiogenesis, DNA damage response, and apoptosis. Given the wide involvement of Myc in cellular dynamics, it is not surprising that its overexpression is frequently associated with cancer. Noteworthy, in cancer cells where high Myc levels are maintained, the overexpression of Myc-associated kinases is often observed and required to foster tumour cells' proliferation. A mutual interplay exists between Myc and kinases: the latter, which are Myc transcriptional targets, phosphorylate Myc, allowing its transcriptional activity, highlighting a clear regulatory loop. At the protein level, Myc activity and turnover is also tightly regulated by kinases, with a finely tuned balance between translation and rapid protein degradation. In this perspective, we focus on the cross-regulation of Myc and its associated protein kinases underlying similar and redundant mechanisms of regulation at different levels, from transcriptional to post-translational events. Furthermore, a review of the indirect effects of known kinase inhibitors on Myc provides an opportunity to identify alternative and combined therapeutic approaches for cancer treatment.

Cancer stem cell in prostate cancer progression, metastasis and therapy resistance

Prostate cancer (PCa) is the most diagnosed malignancy in the men worldwide. Cancer stem cells (CSCs) are the sub-population of cells present in the tumor which possess unique properties of self-renewal and multilineage differentiation thus thought to be major cause of therapy resistance, disease relapse, and mortality in several malignancies including PCa. CSCs have also been shown positive for the common stem cells markers such as ALDH EZH2, OCT4, SOX2, c-MYC, Nanog etc. Therefore, isolation and characterization of CSCs specific markers which may discriminate CSCs and normal stem cells are critical to selectively eliminate CSCs. Rapid advances in the field offers a theoretical explanation for many of the enduring uncertainties encompassing the etiology and an optimism for the identification of new stem-cell targets, development of reliable and efficient therapies in the future. The emerging reports have also provided unprecedented insights into CSCs plasticity, quiescence, renewal, and therapeutic response. In this review, we discuss the identification of PCa stem cells, their unique properties, stemness-driving pathways, new diagnostics, and therapeutic interventions.

Exploring the mechanism and experimental verification of puerarin in the treatment of endometrial carcinoma based on network pharmacology and bioinformatics analysis

Endometrial carcinoma is one of the two cancers with rising mortality and morbidity in recent years. In the light of many controversies about its treatment, it is urgent to construct a new prognostic model and to find out new therapeutic directions. As a small drug molecule widely used in clinical treatment and experimental research in China, puerarin has recently been proven to have obvious anti-cancer effects in multiple cancer cells. In this study, bioinformatics analysis and experimental validation were used to explore the potential mechanism of puerarin for endometrial carcinoma and construct a prognostic model. A total of 22 drug-related differential genes were found by constructing a database of drug targets and disease genes. The protein–protein interaction network was constructed for GO and KEGG enrichment analysis to initially explore the potential mechanism of its therapeutic effects. To construct the prognostic model, validation was performed by risk regression analysis and LASSO analysis. Finally, two prognostic genes—PIM1 and BIRC5 were determined to establish high and low risk groups. Kaplan–Meier analysis displayed a higher survival rate in the low-risk group than in the high-risk group. ROC curves indicated the stable and good effect in prediction (one-year AUC is 0.626; two-year AUC is 0.620; three-year AUC is 0.623). The interrelationship between immunity and its disease was explored by immune infiltration analysis. Finally, the potential effect of puerarin on endometrial carcinoma cells was further verified by experiments.

MYC and therapy resistance in cancer: risks and opportunities

The MYC transcription factor, encoded by the c-MYC proto-oncogene, is activated by growth-promoting signals, and is a key regulator of biosynthetic and metabolic pathways driving cell growth and proliferation. These same processes are deregulated in MYC-driven tumors, where they become critical for cancer cell proliferation and survival. As other oncogenic insults, overexpressed MYC induces a series of cellular stresses (metabolic, oxidative, replicative, etc.) collectively known as oncogenic stress, which impact not only on tumor progression, but also on the response to therapy, with profound, multifaceted consequences on clinical outcome. On one hand, recent evidence uncovered a widespread role for MYC in therapy resistance in multiple cancer types, with either standard chemotherapeutic or targeted regimens. Reciprocally, oncogenic MYC imparts a series of molecular and metabolic dependencies to cells, thus giving rise to cancer-specific vulnerabilities that may be exploited to obtain synthetic-lethal interactions with novel anticancer drugs. Here we will review the current knowledge on the links between MYC and therapeutic responses, and will discuss possible strategies to overcome resistance through new, targeted interventions.

SurviveAI: Long Term Survival Prediction of Cancer Patients Based on Somatic RNA-Seq Expression

Motivation

Prediction of cancer outcome is a major challenge in oncology and is essential for treatment planning. Repositories such as The Cancer Genome Atlas (TCGA) contain vast amounts of data for many types of cancers. Our goal was to create reliable prediction models using TCGA data and validate them using an external dataset.

Results

For 16 TCGA cancer type cohorts we have optimized a Random Forest prediction model using parameter grid search followed by a backward feature elimination loop for dimensions reduction. For each feature that was removed, the model was retrained and the area under the curve of the receiver operating characteristic (AUC-ROC) was calculated using test data. Five prediction models gave AUC-ROC bigger than 80%. We used Clinical Proteomic Tumor Analysis Consortium v3 (CPTAC3) data for validation. The most enriched pathways for the top models were those involved in basic functions related to tumorigenesis and organ development. Enrichment for 2 prediction models of the TCGA-KIRP cohort was explored, one with 42 genes (AUC-ROC = 0.86) the other is composed of 300 genes (AUC-ROC = 0.85). The most enriched networks for both models share only 5 network nodes: DMBT1, IL11, HOXB6, TRIB3, PIM1. These genes play a significant role in renal cancer and might be used for prognosis prediction and as candidate therapeutic targets.

Availability And Implementation

The prediction models were created and tested using Python SciKit-Learn package. They are freely accessible via a friendly web interface we called surviveAI at https://tinyurl.com/surviveai.

Longitudinal single-cell transcriptomics reveals distinct patterns of recurrence in acute myeloid leukemia

Background

Acute myeloid leukemia (AML) is a heterogeneous and aggressive blood cancer that results from diverse genetic aberrations in the hematopoietic stem or progenitor cells (HSPCs) leading to the expansion of blasts in the hematopoietic system. The heterogeneity and evolution of cancer blasts can render therapeutic interventions ineffective in a yet poorly understood patient-specific manner. In this study, we investigated the clonal heterogeneity of diagnosis (Dx) and relapse (Re) pairs at genetic and transcriptional levels, and unveiled the underlying pathways and genes contributing to recurrence.

Methods

Whole-exome sequencing was used to detect somatic mutations and large copy number variations (CNVs). Single cell RNA-seq was performed to investigate the clonal heterogeneity between Dx-Re pairs and amongst patients.

Results

scRNA-seq analysis revealed extensive expression differences between patients and Dx-Re pairs, even for those with the same -presumed- initiating events. Transcriptional differences between and within patients are associated with clonal composition and evolution, with the most striking differences in patients that gained large-scale copy number variations at relapse. These differences appear to have significant molecular implications, exemplified by a DNMT3A/FLT3-ITD patient where the leukemia switched from an AP-1 regulated clone at Dx to a mTOR signaling driven clone at Re. The two distinct AML1-ETO pairs share genes related to hematopoietic stem cell maintenance and cell migration suggesting that the Re leukemic stem cell-like (LSC-like) cells evolved from the Dx cells.

Conclusions

In summary, the single cell RNA data underpinned the tumor heterogeneity not only amongst patient blasts with similar initiating mutations but also between each Dx-Re pair. Our results suggest alternatively and currently unappreciated and unexplored mechanisms leading to therapeutic resistance and AML recurrence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-022-01635-4.

Longitudinal single-cell transcriptomics reveals distinct patterns of recurrence in acute myeloid leukemia

BACKGROUND

Acute myeloid leukemia (AML) is a heterogeneous and aggressive blood cancer that results from diverse genetic aberrations in the hematopoietic stem or progenitor cells (HSPCs) leading to the expansion of blasts in the hematopoietic system. The heterogeneity and evolution of cancer blasts can render therapeutic interventions ineffective in a yet poorly understood patient-specific manner. In this study, we investigated the clonal heterogeneity of diagnosis (Dx) and relapse (Re) pairs at genetic and transcriptional levels, and unveiled the underlying pathways and genes contributing to recurrence.

METHODS

Whole-exome sequencing was used to detect somatic mutations and large copy number variations (CNVs). Single cell RNA-seq was performed to investigate the clonal heterogeneity between Dx-Re pairs and amongst patients.

RESULTS

scRNA-seq analysis revealed extensive expression differences between patients and Dx-Re pairs, even for those with the same -presumed- initiating events. Transcriptional differences between and within patients are associated with clonal composition and evolution, with the most striking differences in patients that gained large-scale copy number variations at relapse. These differences appear to have significant molecular implications, exemplified by a DNMT3A/FLT3-ITD patient where the leukemia switched from an AP-1 regulated clone at Dx to a mTOR signaling driven clone at Re. The two distinct AML1-ETO pairs share genes related to hematopoietic stem cell maintenance and cell migration suggesting that the Re leukemic stem cell-like (LSC-like) cells evolved from the Dx cells.

CONCLUSIONS

In summary, the single cell RNA data underpinned the tumor heterogeneity not only amongst patient blasts with similar initiating mutations but also between each Dx-Re pair. Our results suggest alternatively and currently unappreciated and unexplored mechanisms leading to therapeutic resistance and AML recurrence.

Prostate cancer addiction to oxidative stress defines sensitivity to anti-tumor neutrophils

Bone metastatic prostate cancer (BM-PCa) remains one of the most difficult cancers to treat due to the complex interactions of cancer and stromal cells. We previously showed that bone marrow neutrophils elicit an anti-tumor immune response against BM-PCa. Further, we demonstrated that BM-PCa induces neutrophil oxidative burst, which has previously been identified to promote primary tumor growth of other cancers, and a goal of this study was to define the importance of neutrophil oxidative burst in BM-PCa. To do this, we first examined the impact of depletion of reactive oxygen species (ROS), via systemic deletion of the main source of ROS in phagocytes, NADPH oxidase (Nox)2, which we found to suppress prostate tumor growth in bone. Further, using pharmacologic ROS inhibitors and Nox2-null neutrophils, we found that ROS depletion specifically suppresses growth of androgen-insensitive prostate cancer cells. Upon closer examination using bulk RNA sequencing analysis, we identified that metastatic prostate cancer induces neutrophil transcriptomic changes that activates pathways associated with response to oxidative stress. In tandem, prostate cancer cells resist neutrophil anti-tumor response via extracellular (i.e., regulation of neutrophils) and intracellular alterations of glutathione synthesis, the most potent cellular antioxidant. These findings demonstrate that BM-PCa thrive under oxidative stress conditions and such that regulation of ROS and glutathione programming could be leveraged for targeting of BM-PCa progression.

Synergistic PIM kinase and proteasome inhibition as a therapeutic strategy for MYC-overexpressing triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the breast cancer subtype with the poorest clinical outcome. The PIM family of kinases has emerged as a factor that is both overexpressed in TNBC and associated with poor outcomes. Preclinical data suggest that TNBC with an elevated MYC expression is sensitive to PIM inhibition. However, clinical observations indicate that the efficacy of PIM inhibitors as single agents may be limited, suggesting the need for combination therapies. Our screening effort identifies PIM and the 20S proteasome inhibition as the most synergistic combination. PIM inhibitors, when combined with proteasome inhibitors, induce significant antitumor effects, including abnormal accumulation of poly-ubiquitinated proteins, increased proteotoxic stress, and the inability of NRF1 to counter loss in proteasome activity. Thus, the identified combination could represent a rational combination therapy against MYC-overexpressing TNBC that is readily translatable to clinical investigations.

Stabilization of PIM Kinases in Hypoxia Is Mediated by the Deubiquitinase USP28

Proviral integration sites for Moloney murine leukemia virus (PIM) kinases are upregulated at the protein level in response to hypoxia and have multiple protumorigenic functions, promoting cell growth, survival, and angiogenesis. However, the mechanism responsible for the induction of PIM in hypoxia remains unknown. Here, we examined factors affecting PIM kinase stability in normoxia and hypoxia. We found that PIM kinases were upregulated in hypoxia at the protein level but not at the mRNA level, confirming that PIMs were upregulated in hypoxia in a hypoxia inducible factor 1-independent manner. PIM kinases were less ubiquitinated in hypoxia than in normoxia, indicating that hypoxia reduced their proteasomal degradation. We identified the deubiquitinase ubiquitin-specific protease 28 (USP28) as a key regulator of PIM1 and PIM2 stability. The overexpression of USP28 increased PIM protein stability and total levels in both normoxia and hypoxia, and USP28-knockdown significantly increased the ubiquitination of PIM1 and PIM2. Interestingly, coimmunoprecipitation assays showed an increased interaction between PIM1/2 and USP28 in response to hypoxia, which correlated with reduced ubiquitination and increased protein stability. In a xenograft model, USP28-knockdown tumors grew more slowly than control tumors and showed significantly lower levels of PIM1 in vivo. In conclusion, USP28 blocked the ubiquitination and increased the stability of PIM1/2, particularly in hypoxia. These data provide the first insight into proteins responsible for controlling PIM protein degradation and identify USP28 as an important upstream regulator of this hypoxia-induced, protumorigenic signaling pathway.

Identification of a risk prediction model for clinical prognosis in HER2 positive breast cancer patients

Background New biomarkers are needed to identify different clinical outcomes for HER2+ breast cancer (BC). Methods Differential genes of HER2+ BC were screened based on TCGA database. We used WGCNA to identify the genes related to the survival. Genetic Algorithm was used to structure risk prediction model. The prognostic model was validated in GSE data. Results We constructed a risk prediction model of 6 genes to identify prognosis of HER2+ BC, including CLEC9A, PLD4, PIM1, PTK2B, AKNAD1 and C15orf27. Kaplan-Meier curve showed that the model effectively distinguished the survival of HER2+ BC patients. The multivariate Cox regression suggested that the risk model was an independent predictor for HER2+ BC. Analysis related to immune showed that significant differences in immune infiltration between high- and low-risk groups classified by the prognostic model. Conclusions Our study identified a risk prediction model of 6 genes that could distinguish the prognosis of HER2+ BC.

Ribosomal proteins and human diseases: molecular mechanisms and targeted therapy

Ribosome biogenesis and protein synthesis are fundamental rate-limiting steps for cell growth and proliferation. The ribosomal proteins (RPs), comprising the structural parts of the ribosome, are essential for ribosome assembly and function. In addition to their canonical ribosomal functions, multiple RPs have extra-ribosomal functions including activation of p53-dependent or p53-independent pathways in response to stress, resulting in cell cycle arrest and apoptosis. Defects in ribosome biogenesis, translation, and the functions of individual RPs, including mutations in RPs have been linked to a diverse range of human congenital disorders termed ribosomopathies. Ribosomopathies are characterized by tissue-specific phenotypic abnormalities and higher cancer risk later in life. Recent discoveries of somatic mutations in RPs in multiple tumor types reinforce the connections between ribosomal defects and cancer. In this article, we review the most recent advances in understanding the molecular consequences of RP mutations and ribosomal defects in ribosomopathies and cancer. We particularly discuss the molecular basis of the transition from hypo- to hyper-proliferation in ribosomopathies with elevated cancer risk, a paradox termed "Dameshek's riddle." Furthermore, we review the current treatments for ribosomopathies and prospective therapies targeting ribosomal defects. We also highlight recent advances in ribosome stress-based cancer therapeutics. Importantly, insights into the mechanisms of resistance to therapies targeting ribosome biogenesis bring new perspectives into the molecular basis of cancer susceptibility in ribosomopathies and new clinical implications for cancer therapy.

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.

Lineage Plasticity in Cancer: The Tale of a Skin-Walker

Lineage plasticity, the switching of cells from one lineage to another, has been recognized as a cardinal property essential for embryonic development, tissue repair and homeostasis. However, such a highly regulated process goes awry when cancer cells exploit this inherent ability to their advantage, resulting in tumorigenesis, relapse, metastasis and therapy resistance. In this review, we summarize our current understanding on the role of lineage plasticity in tumor progression and therapeutic resistance in multiple cancers. Lineage plasticity can be triggered by treatment itself and is reported across various solid as well as liquid tumors. Here, we focus on the importance of lineage switching in tumor progression and therapeutic resistance of solid tumors such as the prostate, lung, hepatocellular and colorectal carcinoma and the myeloid and lymphoid lineage switch observed in leukemias. Besides this, we also discuss the role of epithelial-mesenchymal transition (EMT) in facilitating the lineage switch in biphasic cancers such as aggressive carcinosarcomas. We also discuss the mechanisms involved, current therapeutic approaches and challenges that lie ahead in taming the scourge of lineage plasticity in cancer.

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 Kinase and PI3K/mTOR in NSCLC

Simple Summary

PIM kinases interact with major oncogenic players, including the PI3K/Akt pathway, and provide an escape mechanism leading to drug resistance. This study examined PIM kinase expression in NSCLC and the potential of PIM1 as a prognostic marker. The effect on cell signaling of novel preclinical PI3K/mTOR/PIM kinase inhibitor IBL-301 was compared to PI3K/mTOR inhibition in vitro and ex vivo. PI3K-mTOR inhibitor sensitive (H1975P) and resistant (H1975GR) cells were compared for altered IL6/STAT3 pathway expression and sensitivity to IBL-301. All three PIM kinases are expressed in NSCLC and PIM1 is a marker of poor prognosis. IBL-301 inhibited c-Myc, the PI3K-Akt and JAK/STAT pathways in vitro and in NSCLC tumor tissue explants. IBL-301 also inhibited secreted pro-inflammatory cytokine MCP-1. PIM kinases were activated in H1975GR cells which were more sensitive to IBL-301 than H1975P cells. A miRNA signature of PI3K-mTOR resistance was validated. Co-targeting PIM kinase and PI3K-mTOR warrants further clinical investigation.

Abstract

PIM kinases are constitutively active proto-oncogenic serine/threonine kinases that play a role in cell cycle progression, metabolism, inflammation and drug resistance. PIM kinases interact with and stabilize p53, c-Myc and parallel signaling pathway PI3K/Akt. This study evaluated PIM kinase expression in NSCLC and in response to PI3K/mTOR inhibition. It investigated a novel preclinical PI3K/mTOR/PIM inhibitor (IBL-301) in vitro and in patient-derived NSCLC tumor tissues. Western blot analysis confirmed PIM1, PIM2 and PIM3 are expressed in NSCLC cell lines and PIM1 is a marker of poor prognosis in patients with NSCLC. IBL-301 decreased PIM1, c-Myc, pBAD and p4EBP1 (Thr37/46) and peIF4B (S406) protein levels in-vitro and MAP kinase, PI3K-Akt and JAK/STAT pathways in tumor tissue explants. IBL-301 significantly decreased secreted pro-inflammatory cytokine MCP-1. Altered mRNA expression, including activated PIM kinase and c-Myc, was identified in Apitolisib resistant cells (H1975GR) by an IL-6/STAT3 pathway array and validated by Western blot. H1975GR cells were more sensitive to IBL-301 than parent cells. A miRNA array identified a dysregulated miRNA signature of PI3K/mTOR drug resistance consisting of regulators of PIM kinase and c-Myc (miR17-5p, miR19b-3p, miR20a-5p, miR15b-5p, miR203a, miR-206). Our data provides a rationale for co-targeting PIM kinase and PI3K-mTOR to improve therapeutic response in NSCLC.

Identification of PIM1 substrates reveals a role for NDRG1 phosphorylation in prostate cancer cellular migration and invasion

PIM1 is a serine/threonine kinase that promotes and maintains prostate tumorigenesis. While PIM1 protein levels are elevated in prostate cancer relative to local disease, the mechanisms by which PIM1 contributes to oncogenesis have not been fully elucidated. Here, we performed a direct, unbiased chemical genetic screen to identify PIM1 substrates in prostate cancer cells. The PIM1 substrates we identified were involved in a variety of oncogenic processes, and included N-Myc Downstream-Regulated Gene 1 (NDRG1), which has reported roles in suppressing cancer cell invasion and metastasis. NDRG1 is phosphorylated by PIM1 at serine 330 (pS330), and the level of NDRG1 pS330 is associated higher grade prostate tumors. We have shown that PIM1 phosphorylation of NDRG1 at S330 reduced its stability, nuclear localization, and interaction with AR, resulting in enhanced cell migration and invasion.

Anti-leukemic effect of CDK9 inhibition in T-cell prolymphocytic leukemia

T-cell prolymphocytic leukemia (T-PLL) is an aggressive malignancy characterized by chemotherapy resistance and a median survival of less than 2 years. Here, we investigated the pharmacological effects of the novel highly specific cyclin-dependent kinase 9 (CDK9) inhibitor LDC526 and its clinically used derivate atuveciclib employing primary T-PLL cells in an ex vivo drug sensitivity testing platform. Importantly, all T-PLL samples were sensitive to CDK9 inhibition at submicromolar concentrations, while conventional cytotoxic drugs were found to be largely ineffective. At the cellular level LDC526 inhibited the phosphorylation at serine 2 of the RNA polymerase II C-terminal domain resulting in decreased de novo RNA transcription. LDC526 induced apoptotic leukemic cell death through down-regulating MYC and MCL1 both at the mRNA and protein level. Microarray-based transcriptomic profiling revealed that genes down-modulated in response to CDK9 inhibition were enriched for MYC and JAK-STAT targets. By contrast, CDK9 inhibition increased the expression of the tumor suppressor FBXW7, which may contribute to decreased MYC and MCL1 protein levels. Finally, the combination of atuvecliclib and the BCL2 inhibitor venetoclax exhibited synergistic anti-leukemic activity, providing the rationale for a novel targeted-agent-based treatment of T-PLL.

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.

PIM-1 Is Overexpressed at a High Frequency in Circulating Tumor Cells from Metastatic Castration-Resistant Prostate Cancer Patients

PIM-1 is an oncogene involved in cell cycle progression, cell growth, cell survival and therapy resistance, activated in many types of cancer, and is now considered as a very promising target for cancer therapy. We report for the first time that PIM-1 is overexpressed in circulating tumor cells (CTCs) from metastatic castration-resistant prostate cancer patients (mCRPC). We first developed and validated a highly sensitive RT-qPCR assay for quantification of PIM-1 transcripts. We further applied this assay to study PIM-1 expression in EpCAM⁽⁺⁾ CTC fraction isolated from 64 peripheral blood samples of 50 mCRPC patients. CTC enumeration in all samples was performed using the FDA-cleared CellSearch^® system. PIM-1 overexpression was detected in 24/64 (37.5%) cases, while in 20/24 (83.3%) cases that were positive for PIM-1 expression, at least one CTC/7.5 mL PB was detected in the CellSearch^®. Our data indicate that PIM-1 overexpression is observed at high frequency in CTCs from mCRPC patients and this finding, in combination with androgen receptor splice variant 7 (AR-V7) expression in CTCs, suggest its potential role as a very promising target for cancer therapy. We strongly believe that PIM-1 overexpression in EpCAM⁽⁺⁾ CTC fraction merits to be further evaluated and validated as a non-invasive circulating tumor biomarker in a large and well-defined patient cohort with mCRPC.

TAB3 upregulates PIM1 expression by directly activating the TAK1-STAT3 complex to promote colorectal cancer growth

Transforming growth factor-β-activated kinase 1 (TAK1)-binding protein 3 (TAB3) and the proviral integration site for Moloney murine leukaemia virus 1 (PIM1) are implicated in cancer development. In this study, we investigated the relationship between TAB3 and PIM1 in colorectal cancer (CRC) and determined the potential role and molecular mechanism of TAB3 in PIM1-mediated CRC growth. We found that TAB3 and PIM1 expression levels were positively correlated in CRC tissues. The knockdown of TAB3 significantly decreased PIM1 expression and inhibited CRC proliferation in vitro and in vivo. The upregulation of PIM1 rescued the decreased cell proliferation induced by TAB3 knockdown, whereas PIM1 knockdown decreased TAB3-enhanced CRC proliferation. Additionally, TAB3 regulates PIM1 expression through the STAT3 signalling pathway and confirmed a positive correlation between TAB3 and phosphorylated-STAT3 expression in CRC tissues. Patients with high expression of TAB3 and phosphorylated-STAT3 had the worst prognosis. Mechanistically, TAB3 regulates PIM1 expression by promoting STAT3 phosphorylation and activation through the formation of the TAB3-TAK1-STAT3 complex. Overall, a novel CRC regulatory circuit involving the TAB3-TAK1-STAT3 complex and PIM1 was identified, the dysfunction of which may contribute to CRC tumorigenesis.

Lineage plasticity in cancer: a shared pathway of therapeutic resistance

Lineage plasticity, the ability of cells to transition from one committed developmental pathway to another, has been proposed as a source of intratumoural heterogeneity and of tumour adaptation to an adverse tumour microenvironment including exposure to targeted anticancer treatments. Tumour cell conversion into a different histological subtype has been associated with a loss of dependency on the original oncogenic driver, leading to therapeutic resistance. A well-known pathway of lineage plasticity in cancer - the histological transformation of adenocarcinomas to aggressive neuroendocrine derivatives - was initially described in lung cancers harbouring an EGFR mutation, and was subsequently reported in multiple other adenocarcinomas, including prostate cancer in the presence of antiandrogens. Squamous transformation is a subsequently identified and less well-characterized pathway of adenocarcinoma escape from suppressive anticancer therapy. The increased practice of tumour re-biopsy upon disease progression has increased the recognition of these mechanisms of resistance and has improved our understanding of the underlying biology. In this Review, we provide an overview of the impact of lineage plasticity on cancer progression and therapy resistance, with a focus on neuroendocrine transformation in lung and prostate tumours. We discuss the current understanding of the molecular drivers of this phenomenon, emerging management strategies and open questions in the field.

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.

From genomics to functions: preclinical mouse models for understanding oncogenic pathways in prostate cancer

Next-generation sequencing has revealed numerous genomic alterations that induce aberrant signaling activities in prostate cancer (PCa). Among them are pathways affecting multiple cancer types, including the PI3K/AKT/mTOR, p53, Rb, Ras/Raf/MAPK, Myc, FGF, and Wnt signaling pathways, as well as ones that are prominent in PCa, including alterations in genes of AR signaling, the ETS family, NKX3.1, and SPOP. Cross talk among the oncogenic pathways can confer PCa resistance to therapy, particularly in advanced tumors, which are castration-resistant or show neuroendocrine features. Various experimental models, such as cancer cell lines, animal models, and patient-derived xenografts and organoids have been utilized to dissect PCa progression mechanisms. Here, we review the current preclinical mouse models for studying the most commonly altered pathways in PCa, with an emphasis on their interplays. We highlight the power of genetically engineered mouse models (GEMMs) in translating genomic discoveries into understanding of the functions of these oncogenic events in vivo. Developing and analyzing PCa mouse models will undoubtedly continue to offer new insights into tumor biology and guide novel rationalized therapy.

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 is responsible for IL-6-induced breast cancer cell EMT and stemness via c-myc activation

Background

Interleukin-6 (IL-6) has been demonstrated to be a critical factor for breast cancer malignancy. However, the molecular mechanisms by which IL-6 induce breast cancer cells epithelial–mesenchymal-transition (EMT) and stemness remain elusive.

Methods

Breast cancer cell lines T47D and MCF7 were exposed to IL-6, the expression of PIM1 was examined by quantitative real-time PCR (qRT-PCR) and western blot. Luciferase reporter assay was used to determine the transcriptional modulation of PIM1 by IL-6 and STAT3 inhibitor. Transwell assay was used to detect the invading ability of breast cancer cells induced by IL-6 or PIM1. The expressions of EMT and stemness markers were determined by qRT-PCR.

Results

IL-6 promoted PIM1 expression in a dose- and time-dependent manner, and this induction could be abrogated by inhibiting STAT3 activation, subsequently suppressing the transcriptional level of PIM1. Moreover, we noticed that knocking down of PIM1 in cells which was exposed to IL-6 significantly impaired the invasion ability and the expression of EMT and stemness markers. On the contrary, overexpression of PIM1 promoted cell invasion and upregulated the expression of EMT and stemness markers. In addition, we demonstrated that c-myc, the cofactor of PIM1, involved in the pro-oncogenic roles of PIM1. Knocking down of c-myc attenuated the PIM1-induced cell EMT and stemness.

Conclusion

This study proposed the upregulation of PIM1 by IL-6 contributed to breast cancer cell aggressiveness and targeting PIM1 or c-myc could be novel approaches for breast cancer treatment.

Antiproliferative potential of miR-33a in laryngeal cancer Hep-2 cells via targeting PIM1

BACKGROUND

Laryngeal cancer is a frequent cause of cancer-associated mortality worldwide with an overall poor prognosis along with high mortality rates. Therefore, comprehensive investigation of underlying molecular mechanisms of laryngeal carcinogenesis remains an important problem.

METHODS

In this study, proliferative and apoptotic features of Hep-2 cells overexpressing microRNA-33a (miR-33a) were evaluated and in silico analysis along with literature search was used to find putative targets of miR-33a. The potential of PIM1 (pim-1 oncogene) as a direct target of miR-33a was tested using quantitative real-time polymerase chain reaction, Western blot, and luciferase assay.

RESULTS

Induced miR-33a expression significantly inhibited proliferation through inducing apoptosis of Hep-2 cells. Further in vitro tests showed downregulation of PIM1 in messenger ribonucleic acid (mRNA) and protein level upon miR-33a overexpression and confirmed PIM1 as a direct target of miR-33a.

CONCLUSIONS

Mir-33a was demonstrated to act as a tumor suppressor in larnygeal cancer via directly targeting the 3' untranslated region of PIM1.

c-MYC amplification and c-myc protein expression in pancreatic acinar cell carcinomas. New insights into the molecular signature of these rare cancers

The molecular alterations of pancreatic acinar cell carcinomas (ACCs) and mixed acinar-neuroendocrine carcinomas (MANECs) are not completely understood, and the possible role of c-MYC amplification in tumor development, progression, and prognosis is not known. We have investigated c-MYC gene amplification in a series of 35 ACCs and 4 MANECs to evaluate its frequency and a possible prognostic role. Gene amplification was investigated using interphasic fluorescence in situ hybridization analysis simultaneously hybridizing c-MYC and the centromere of chromosome 8 probes. Protein expression was immunohistochemically investigated using a specific monoclonal anti-c-myc antibody. Twenty cases had clones with different polysomies of chromosome 8 in absence of c-MYC amplification, and 5 cases had one amplified clone and other clones with chromosome 8 polysomy, while the remaining 14 cases were diploid for chromosome 8 and lacked c-MYC amplification. All MANECs showed c-MYC amplification and/or polysomy which were observed in 54% pure ACCs. Six cases (15.3%) showed nuclear immunoreactivity for c-myc, but only 4/39 cases showed simultaneous c-MYC amplification/polysomy and nuclear protein expression. c-myc immunoreactivity as well as c-MYC amplification and/or chromosome 8 polysomy was not statistically associated with prognosis. Our study demonstrates that a subset of ACCs shows c-MYC alterations including gene amplification and chromosome 8 polysomy. Although they are not associated with a different prognostic signature, the fact that these alterations are present in all MANECs suggests a role in the acinar-neuroendocrine differentiation possibly involved in the pathogenesis of MANECs.

HistoneH3 demethylase JMJD2A promotes growth of liver cancer cells through up-regulating miR372

Changes in histone lysine methylation status have been observed during cancer formation. JMJD2A protein is a demethylase that is overexpressed in several tumors. Herein, our results demonstrate that JMJD2A accelerates malignant progression of liver cancer cells in vitro and in vivo. Mechanistically, JMJD2A promoted the expression and mature of pre-miR372 epigenetically. Notably, miR372 blocks the editing of 13th exon-introns-14th exon and forms a novel transcript(JMJD2AΔ) of JMJD2A. In particular, JMJD2A inhibited P21(WAF1/Cip1) expression by decreasing H3K9me3 dependent on JMJD2AΔ. Thereby, JMJD2A could enhance Pim1 transcription by suppressing P21(WAF1/Cip1). Furthermore, through increasing the expression of Pim1, JMJD2A could facilitate the interaction among pRB, CDK2 and CyclinE which prompts the transcription and translation of oncogenic C-myc. Strikingly, JMJD2A may trigger the demethylation of Pim1. On the other hand, Pim1 knockdown and P21(WAF1/Cip1) overexpression fully abrogated the oncogenic function of JMJD2A. Our observations suggest that JMJD2A promotes liver cancer cell cycle progress through JMJD2A-miR372-JMJD2AΔ-P21WAF1/Cip1-Pim1-pRB-CDK2-CyclinE-C-myc axis. This study elucidates a novel mechanism for JMJD2A in liver cancer cells and suggests that JMJD2A can be used as a novel therapeutic targets of liver cancer.

Calcium and Nuclear Signaling in Prostate Cancer

Recently, there have been a number of developments in the fields of calcium and nuclear signaling that point to new avenues for a more effective diagnosis and treatment of prostate cancer. An example is the discovery of new classes of molecules involved in calcium-regulated nuclear import and nuclear calcium signaling, from the G protein-coupled receptor (GPCR) and myosin families. This review surveys the new state of the calcium and nuclear signaling fields with the aim of identifying the unifying themes that hold out promise in the context of the problems presented by prostate cancer. Genomic perturbations, kinase cascades, developmental pathways, and channels and transporters are covered, with an emphasis on nuclear transport and functions. Special attention is paid to the molecular mechanisms behind prostate cancer progression to the malignant forms and the unfavorable response to anti-androgen treatment. The survey leads to some new hypotheses that connect heretofore disparate results and may present a translational interest.

Pim1 supports human colorectal cancer growth during glucose deprivation by enhancing the Warburg effect

Cancer cells metabolize glucose mainly by glycolysis and are well adapted to metabolic stress. Pim1 is an oncogene that promotes colorectal cancer (CRC) growth and metastasis, and its expression is positively correlated with CRC progression. However, the mechanism underlying Pim1 overexpression during CRC progression and the role of Pim1 in CRC metabolism remains unclear. In the present study, we discovered that Pim1 expression was significantly upregulated in response to glucose deprivation‐induced metabolic stress by AMP‐activated protein kinase signaling. Pim1 promoted CRC cell proliferation in vitro and tumorigenicity in vivo. Clinical observations showed that Pim1 expression was higher in CRC tissues than in adjacent normal tissues. Pim1 overexpression in CRC tissues not only predicted CRC prognosis in patients but also showed a positive relationship with ¹⁸F‐fluorodeoxyglucose uptake. Further in vitro experiments showed that Pim1 promoted the Warburg effect and that Pim1 expression was positively correlated with hexokinase 2 and lactate dehydrogenase A expression. Pim1‐silenced cells were more vulnerable to glucose starvation, and Pim1‐induced tumor proliferation or tolerance to glucose starvation was attenuated by blocking the Warburg effect. In conclusion, glucose deprivation is one of the mechanisms that leads to elevated Pim1 expression in CRC, and Pim1 upregulation ensures CRC growth in response to glucose deprivation by facilitating the Warburg effect in a compensatory way.

A Bioluminescent and Fluorescent Orthotopic Syngeneic Murine Model of Androgen-dependent and Castration-resistant Prostate Cancer

Orthotopic tumor modeling is a valuable tool for pre-clinical prostate cancer research, as it has multiple advantages over both subcutaneous and transgenic genetically engineered mouse models. Unlike subcutaneous tumors, orthotopic tumors contain more clinically accurate vasculature, tumor microenvironment, and responses to multiple therapies. In contrast to genetically engineered mouse models, orthotopic models can be performed with lower cost and in less time, involve the use of highly complex and heterogeneous mouse or human cancer cell lines, rather that single genetic alterations, and these cell lines can be genetically modified, such as to express imaging agents. Here, we present a protocol to surgically injecting a luciferase- and mCherry-expressing murine prostate cancer cell line into the anterior prostate lobe of mice. These mice developed orthotopic tumors that were non-invasively monitored in vivo and further analyzed for tumor volume, weight, mouse survival, and immune infiltration. Further, orthotopic tumor-bearing mice were surgically castrated, leading to immediate tumor regression and subsequent recurrence, representing castration-resistant prostate cancer. Although technical skill is required to carry out this procedure, this syngeneic orthotopic model of both androgen-dependent and castration-resistant prostate cancer is of great use to all investigators in the field.