PIM-1 mRNA expression is a potential prognostic biomarker in acute myeloid leukemia

Evolution of transcriptomic profiles in relapsed inv(16) acute myeloid leukemia

Acute myeloid leukemia (AML) with inv(16) is typically associated with a favourable prognosis. However, up to 40 % of patients will eventually experience disease relapse. Herein, we dissected the genomic and transcriptomic profile of inv(16) AML to identify potential prognostic markers and therapeutic vulnerabilities. Sequencing data from 222 diagnostic samples, including 44 relapse/refractory patients, revealed a median of 1 concomitant additional mutation, cooperating with inv(16) in leukemogenesis. Notably, the mutational landscape at diagnosis did not differ significantly between patients experiencing primary induction failure or relapse when compared to the rest of the cohort, except for an increase in the mutational burden in the relapse/refractory group. RNA-Seq of unpaired diagnostic(n=7) and relapse(n=6) samples allowed the identification of oxidative phosphorylation (OXPHOS) as one of the most significantly downregulated pathways at relapse. Considering that OXPHOS could be targeted by Venetoclax/Azacitidine combination, we explored its biological effects on an inv(16) cell-line ME-1, but there was no additional advantage in terms of cell death over Azacitidine alone. To enhance Venetoclax efficacy, we tested in vitro effects of Metformin as a potential drug able to enhance chemosensitivity of AML cells by inhibiting the mitochondrial transfer. By challenging ME-1 with this combination, we observed a significant synergistic interaction at least similar to that of Venetoclax/Azacitidine. In conclusions, we identified a downregulated expression of oxidative phosphorylation (OXPHOS) at relapse in AML with inv(16), and explored the in vitro effects of metformin as a potential drug to enhance chemosensitivity in this setting.

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.

The Myc Family and the Metastasis Suppressor NDRG1: Targeting Key Molecular Interactions with Innovative Therapeutics

Cancer is a leading cause of death worldwide, resulting in ∼10 million deaths in 2020. Major oncogenic effectors are the Myc proto-oncogene family, which consists of three members including c-Myc, N-Myc, and L-Myc. As a pertinent example of the role of the Myc family in tumorigenesis, amplification of MYCN in childhood neuroblastoma strongly correlates with poor patient prognosis. Complexes between Myc oncoproteins and their partners such as hypoxia-inducible factor-1α and Myc-associated protein X (MAX) result in proliferation arrest and pro-proliferative effects, respectively. Interactions with other proteins are also important for N-Myc activity. For instance, the enhancer of zest homolog 2 (EZH2) binds directly to N-Myc to stabilize it by acting as a competitor against the ubiquitin ligase, SCFFBXW7, which prevents proteasomal degradation. Heat shock protein 90 may also be involved in N-Myc stabilization since it binds to EZH2 and prevents its degradation. N-Myc downstream-regulated gene 1 (NDRG1) is downregulated by N-Myc and participates in the regulation of cellular proliferation via associating with other proteins, such as glycogen synthase kinase-3β and low-density lipoprotein receptor-related protein 6. These molecular interactions provide a better understanding of the biologic roles of N-Myc and NDRG1, which can be potentially used as therapeutic targets. In addition to directly targeting these proteins, disrupting their key interactions may also be a promising strategy for anti-cancer drug development. This review examines the interactions between the Myc proteins and other molecules, with a special focus on the relationship between N-Myc and NDRG1 and possible therapeutic interventions. SIGNIFICANCE STATEMENT: Neuroblastoma is one of the most common childhood solid tumors, with a dismal five-year survival rate. This problem makes it imperative to discover new and more effective therapeutics. The molecular interactions between major oncogenic drivers of the Myc family and other key proteins; for example, the metastasis suppressor, NDRG1, may potentially be used as targets for anti-neuroblastoma drug development. In addition to directly targeting these proteins, disrupting their key molecular interactions may also be promising for drug discovery.

Targeting Pim kinases in hematological cancers: molecular and clinical review

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

Relationship between the transcriptional expression of PIM1 and local control in patients with head and neck squamous cell carcinomas treated with radiotherapy

Purpose

Proviral integration site for Moloney murine leukemia virus (PIMs) are proto-oncogenes encoding serine/threonine kinases that phosphorylate a variety of substrates involved in the regulation of cellular processes. Elevated expression of PIM-1 has been associated with poor prognosis in several types of cancer. There are no studies that have analyzed the response to radiotherapy in patients with head and neck squamous cell carcinoma (HNSCC) according to the expression of PIM-1. The aim of our study was to analyze the relationship between the transcriptional expression of PIM-1 and local response to radiotherapy in HNSCC patients.

Methods

We determined the transcriptional expression of PIM-1 in 135 HNSCC patients treated with radiotherapy, including patients treated with chemoradiotherapy (n = 65) and bioradiotherapy (n = 15).

Results

During the follow-up, 48 patients (35.6%) had a local recurrence of the tumor. Patients with local recurrence had a higher level of PIM-1 expression than those who achieved local control of the disease (P = 0.017). Five-year local recurrence-free survival for patients with a high expression of PIM-1 (n = 43) was 44.6% (95% CI 29.2–60.0%), and for patients with low expression (n = 92) it was 71.9% (95% CI 62.5–81.3%) (P = 0.007). According to the results of multivariate analysis, patients with a high PIM-1 expression had a 2.2-fold increased risk of local recurrence (95% CI 1.22–4.10, P = 0.009).

Conclusion

Patients with elevated transcriptional expression levels of PIM-1 had a significantly higher risk of local recurrence after radiotherapy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00405-021-07223-4.

Clinical Significance of Pim-1 in Human Cancers: A Meta-analysis of Association with Prognosis and Clinicopathological Characteristics

Background

Pim-1 is overexpressed in cancer tissues and plays a vital role in carcinogenesis. However, its clinical significance in cancers is not fully verified by meta-analysis, especially in relation to prognosis and clinicopathological features.

Methods

Four databases, PubMed, Embase, Cochrane Library, and Web of Science, were searched. Literature screening and data extraction according to the inclusion and exclusion criteria. The quality of the included literatures was evaluated using the Newcastle-Ottawa scale and the data analysis was performed using STATA and Review Manager software.

Results

15 articles were finally included for meta-analysis, involving 1651 patients. Effect-size pooling analysis showed that high Pim-1 was related to poor overall survival (OS) (HR 1.68 [95% CI 1.17-2.40], P = .004) and disease-free survival (DFS) (HR 2.15 [95 %CI 1.15-4.01], P = .000). Subgroup analysis indicated that the detection techniques of Pim-1 were the main sources of heterogeneity, and 2 literatures using quantitative polymerase chain reaction (qPCR) for Pim-1mRNA had high homogeneity (I² = .0%, P = .321) in OS. Another 13 studies that applied immunohistochemistry (IHC) for Pim-1 protein had significant heterogeneity (I²=82.2%, P = .000; I²=92%, P = .000) in OS and DFS, respectively, and further analysis demonstrated that ethnicity, sample size, and histopathological origin were considered to be the main factors affecting their heterogeneity. In addition, high Pim-1 was associated with lymph node metastasis (OR 1.40 [95% CI 1.02-1.92], P = .04), distant metastasis (OR 2.69 [95%CI 1.67-4.35], P < .0001), and clinical stage III-IV (OR .7 [95% CI .50-.96, P = .03). Sensitivity analysis suggested that the pooled results of each effect-size were stable and reliable, and there was no significant publication bias (P = .138) in all included articles.

Conclusion

High Pim-1 can not only predict poor OS and DFS of cancer, but also help to infer the malignant clinical characteristics of tumor metastasis. Pim-1 may be a potential and promising biomarker for early diagnosis, prognostic analysis and targeted therapy of tumors.

Novel Pan-Pim Kinase Inhibitors With Imidazopyridazine and Thiazolidinedione Structure Exert Potent Antitumor Activities

Pim kinases are overexpressed in various types of hematological malignancies and solid carcinomas, and promote cell proliferation and survival. Here in this study, we investigated the preclinical profile of novel pan-Pim kinase inhibitors with imidazopyridazine and thiazolidinedione structure. Imidazopyridazine-thiazolidinediones inhibited activities of Pim kinases with IC₅₀ values of tens to hundreds nanomolar. With YPC-21440 and/or YPC-21817, which exhibited especially high inhibitory activities against Pim kinases, we investigated in vitro and in vivo activities of imidazopyridazine-thiazolidinediones. In silico analysis of binding mode of YPC-21440 and Pim kinases revealed that it directly bound to ATP-binding pockets of Pim kinases. In the kinase panel tested, YPC-21440 and YPC-21817 were highly specific to Pim kinases. These compounds exerted antiproliferative activities against various cancer cell lines derived from hematological malignancies and solid carcinomas. Furthermore, they suppressed phosphorylation of Pim kinase substrates, arrested cell cycle at the G1 phase, and induced apoptosis in cultured cancer cells. In tumor xenograft models, YPC-21440 methanesulfonate and YPC-21817 methanesulfonate exerted antitumor activities. Furthermore, pharmacodynamic analysis with a xenograft model suggested that YPC-21817 methanesulfonate inhibited Pim kinases in tumors. In conclusion, our data revealed that imidazopyridazine-thiazolidinediones are novel Pim kinases inhibitors, effective on various types of cancer cell lines both in vitro and in vivo.

CXCL2 benefits acute myeloid leukemia cells in hypoxia

INTRODUCTION

Drug resistance and relapse of acute myeloid leukemia (AML) is still an important problem in the treatment of leukemia. Leukemia outbreak causes severe hypoxia in bone marrow (BM), remolding BM microenvironment (niche), and transforming hematopoietic stem cell (HSC) niche into leukemia stem cell (LSC) niche. AML cells and the microenvironment usually conduct "cross-talk" through cytokines to anchor resistant AML cells into LSC niche, thus supporting their survival. Therefore, this study was aimed to investigate the role of CXCL2 in the hypoxic AML niche.

METHODS

AML hypoxic niche was simulated by hypoxic culture of THP-1 and HL-60 cells in vitro, thus to study the effects of CXCL2 on the proliferation and migration of AML cells. The expression of hypoxia-inducible factor-1α (HIF-1α) and the activation of survival-related kinases such as PIM2 and mTOR under CoCl₂ -simulated hypoxic conditions were detected. The correlation between CXCL2 and the prognosis of AML with big data was verified.

RESULTS

(a) CXCL2 promoted the proliferation and migration of AML cells. (b) CXCL2 up-regulated the expression of PIM2 by enhancing the transcriptional activity of HIF-1α. (c) CXCL2 activated mTOR in AML cells. (d) CXCL2 was associated with poor prognosis in AML.

CONCLUSION

CXCL2 promotes survival, migration, and drug resistance pathway of AML cells in hypoxia and is associated with poor prognosis in AML. Therefore, CXCL2 can be considered as an important factor in promoting the development of AML cells in hypoxia.

PIM kinases mediate resistance to cisplatin chemotherapy in hepatoblastoma

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

The targetable kinase PIM1 drives ALK inhibitor resistance in high-risk neuroblastoma independent of MYCN status

Resistance to anaplastic lymphoma kinase (ALK)-targeted therapy in ALK-positive non-small cell lung cancer has been reported, with the majority of acquired resistance mechanisms relying on bypass signaling. To proactively identify resistance mechanisms in ALK-positive neuroblastoma (NB), we herein employ genome-wide CRISPR activation screens of NB cell lines treated with brigatinib or ceritinib, identifying PIM1 as a putative resistance gene, whose high expression is associated with high-risk disease and poor survival. Knockdown of PIM1 sensitizes cells of differing MYCN status to ALK inhibitors, and in patient-derived xenografts of high-risk NB harboring ALK mutations, the combination of the ALK inhibitor ceritinib and PIM1 inhibitor AZD1208 shows significantly enhanced anti-tumor efficacy relative to single agents. These data confirm that PIM1 overexpression decreases sensitivity to ALK inhibitors in NB, and suggests that combined front-line inhibition of ALK and PIM1 is a viable strategy for the treatment of ALK-positive NB independent of MYCN status.

New Mechanistic Insight on the PIM-1 Kinase Inhibitor AZD1208 Using Multidrug Resistant Human Erythroleukemia Cell Lines and Molecular Docking Simulations

Background:

PIM-1 is a kinase which has been related to the oncogenic processes like cell survival, proliferation, and multidrug resistance (MDR). This kinase is known for its ability to phosphorylate the main extrusion pump (ABCB1) related to the MDR phenotype.

Objective:

In the present work, we tested a new mechanistic insight on the AZD1208 (PIM-1 specific inhibitor) under interaction with chemotherapy agents such as Daunorubicin (DNR) and Vincristine (VCR).

Materials and Methods:

In order to verify a potential cytotoxic effect based on pharmacological synergism, two MDR cell lines were used: Lucena (resistant to VCR) and FEPS (resistant to DNR), both derived from the K562 non-MDR cell line, by MTT analyses. The activity of Pgp was ascertained by measuring accumulation and the directional flux of Rh123. Furthermore, we performed a molecular docking simulation to delve into the molecular mechanism of PIM-1 alone, and combined with chemotherapeutic agents (VCR and DNR).

Results:

Our in vitro results have shown that AZD1208 alone decreases cell viability of MDR cells. However, co-exposure of AZD1208 and DNR or VCR reverses this effect. When we analyzed the ABCB1 activity AZD1208 alone was not able to affect the pump extrusion. Differently, co-exposure of AZD1208 and DNR or VCR impaired ABCB1 activity, which could be explained by compensatory expression of abcb1 or other extrusion pumps not analyzed here. Docking analysis showed that AZD1208 is capable of performing hydrophobic interactions with PIM-1 ATP- binding-site residues with stronger interaction-based negative free energy (FEB, kcal/mol) than the ATP itself, mimicking an ATP-competitive inhibitory pattern of interaction. On the same way, VCR and DNR may theoretically interact at the same biophysical environment of AZD1208 and also compete with ATP by the PIM-1 active site. These evidences suggest that AZD1208 may induce pharmacodynamic interaction with VCR and DNR, weakening its cytotoxic potential in the ATP-binding site from PIM-1 observed in the in vitro experiments.

Conclusion:

Finally, the current results could have a pre-clinical relevance potential in the rational polypharmacology strategies to prevent multiple-drugs resistance in human leukemia cancer therapy.

The role of dorsal root ganglia PIM1 in peripheral nerve injury-induced neuropathic pain

Neuropathic pain induced by peripheral nerve injury is a complex and chronic state that is accompanied by poor quality of life. However, whether PIM1 (proviral integration site 1) contributes to the development of nociceptive hypersensitivity induced by nerve injury remains unknown. The present study was designed to investigate the effects of PIM1 on spinal nerve ligation (SNL) induced pain hypersensitivity. Here, we found that PIM1 positive neurons in the dorsal root ganglion (DRG) were colocalized with nociceptive neuronal markers CGRP, IB4 and substance P and were upregulated after SNL surgery. Knockdown PIM1 in the DRG by AAV5-shPIM1 alleviated SNL-induced pain hypersensitivity. In neuroblastoma cells (neuro-2a), PIM1 regulated the expression of CXCR4 phosphorylated at ser339 (pCXCR4) as well as the CXCL12/CXCR4 pathway. In the DRG tissues, we found that PIM1 was co-expressed with CXCR4, and knockdown of PIM1 attenuated pCXCR4 (ser339) protein expression but had little effect on total CXCR4 protein expression after SNL surgery. These findings suggest that PIM1 contributes to nerve injury-induced nociceptive hypersensitivity. Based on these findings and the characteristics of PIM1, we speculate that PIM1 might be a viable therapeutic target for the treatment of neuropathic pain in the near future.

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.

Pan-PIM kinase inhibitors enhance Lenalidomide's anti-myeloma activity via cereblon-IKZF1/3 cascade

Multiple myeloma remains an incurable disease, and continued efforts are required to develop novel agents and novel drug combinations with more effective anti-myeloma activity. Here, we show that the pan-PIM kinase inhibitors SGI1776 and CX6258 exhibit significant anti-myeloma activity and that combining a pan-PIM kinase inhibitor with the immunomodulatory agent lenalidomide in an in vivo myeloma xenograft mouse model resulted in synergistic myeloma cell killing without additional hematologic or hepatic toxicities. Further investigations indicated that treatment with a pan-PIM kinase inhibitor promoted increased ubiquitination and subsequent degradation of IKZF1 and IKZF3, two transcription factors crucial for survival of myeloma cells. Combining a pan-PIM kinase inhibitor with lenalidomide led to more effective degradation of IKZF1 and IKZF3 in multiple myeloma cell lines as well as xenografts of myeloma tumors. We also demonstrated that treatment with a pan-PIM kinase inhibitor resulted in increased expression of cereblon, and that knockdown of cereblon via a shRNA lentivirus abolished the effects of PIM kinase inhibition on the degradation of IKZF1 and IKZF3 and myeloma cell apoptosis, demonstrating a central role of cereblon in pan-PIM kinase inhibitor-mediated down-regulation of IKZF1 and IKZF3 and myeloma cell killing. These data elucidate the mechanism of pan-PIM kinase inhibitor mediated anti-myeloma effect and the rationale for the synergy observed with lenalidomide co-treatment, and provide justification for a clinical trial of the combination of pan-PIM kinase inhibitors and lenalidomide for the treatment of multiple myeloma.

Dysregulation of miR-200s clusters as potential prognostic biomarkers in acute myeloid leukemia

Background

Increasing studies showed that miR-200 family (miR-200s) clusters are aberrantly expressed in multiple human cancers, and miR-200s clusters function as tumor suppressor genes by affecting cell proliferation, self-renewal, differentiation, division and apoptosis. Herein, we aimed to investigate the expression and clinical implication of miR-200s clusters in acute myeloid leukemia (AML).

Methods

RT-qPCR was performed to detect expression of miR-200s clusters in 19 healthy donors, 98 newly diagnosed AML patients, and 35 AML patients achieved complete remission (CR).

Results

Expression of miR-200a/200b/429 cluster but not miR-200c/141 cluster was decreased in newly diagnosed AML patients as compared to healthy donors and AML patients achieved CR. Although no significant differences were observed between miR-200s clusters and most of the features, low expression of miR-200s clusters seems to be associated with higher white blood cells especially for miR-200a/200b. Of the five members of miR-200s clusters, low expression of miR-200b/429/200c was found to be associated with lower CR rate. Logistic regression analysis further revealed that low expression of miR-429 acted as an independent risk factor for CR in AML. Based on Kaplan–Meier analysis, low expression of miR-200b/429/200c was associated with shorter OS, whereas miR-200a/141 had a trend. Moreover, multivariate analysis of Cox regression models confirmed the independently prognostic value of miR-200b expression for OS in AML.

Conclusions

Expression of miR-200a/200b/429 cluster was frequently down-regulated in AML, and low expression of miR-429 as an independent risk factor for CR, whereas low expression of miR-200b as an independent prognostic biomarker for OS.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1494-7) contains supplementary material, which is available to authorized users.