Development of an Imidazopyridazine-Based MNK1/2 Inhibitor for the Treatment of Lymphoma.

The mitogen-activated protein kinase-interacting protein kinases (MNKs) are the only kinases known to phosphorylate eukaryotic translation initiation factor 4E (eIF4E) at Ser209, which plays a significant role in cap-dependent translation. Dysregulation of the MNK/eIF4E axis has been found in various solid tumors and hematological malignancies, including diffuse large B-cell lymphoma (DLBCL). Herein, structure-activity relationship studies and docking models determined that 20j exhibits excellent MNK1/2 inhibitory activity, stability, and hERG safety. 20j exhibits strong and broad antiproliferative activity against different cancer cell lines, especially GCB-DLBCL DOHH2. 20j suppresses the phosphorylation of eIF4E in Hela cells (IC50 = 90.5 nM) and downregulates the phosphorylation of eIF4E and 4E-BP1 in A549 cells. In vivo studies first revealed that ibrutinib enhances the antitumor effect of 20j without side effects in a DOHH2 xenograft model. This study provided a solid foundation for the future development of a MNK inhibitor for GCB-DLBCL treatment.

Design, synthesis and biological evaluation of imidazopyridazine derivatives containing isoquinoline group as potent MNK1/2 inhibitors.

Mitogen-activated protein kinase (MAPK)-interacting kinases (MNKs) are located at the meeting-point of ERK and p38 MAPK signaling pathways, which can phosphorylate eukaryotic translation initiation factor 4E (eIF4E) at the conserved serine 209 exclusively. MNKs modulate the translation of mRNA involved in tumor-associated signaling pathways. Consequently, selective inhibitors of MNK1/2 could reduce the level of phosphorylated eIF4E. Series of imidazopyrazines, imidazopyridazines and imidazopyridines derivatives were synthesized and evaluated as MNK1/2 inhibitors. Several compounds exhibited great inhibitory activity against MNK1/2 and selected compounds showed moderate to excellent anti-proliferative potency against diffuse large B-cell lymphoma (DLBCL) cell lines. In particular, compound II-5 (MNK1 IC50 = 2.3 nM; MNK2 IC50 = 3.4 nM) exhibited excellent enzymatic inhibitory potency and proved to be the most potent compound against TMD-8 and DOHH-2 cell lines with IC50 value of 0.3896 µM and 0.4092 µM respectively. These results demonstrated that compound II-5 could be considered as a potential MNK1/2 inhibitor for further investigation.

Design, synthesis and biological evaluation of pyridone-aminal derivatives as MNK1/2 inhibitors.

Excessive phosphorylation of eukaryotic translation initiation factor 4E (eIF4E) plays a major role in the dysregulation of mRNA translation and the activation of tumor cell signaling. eIF4E is exclusively phosphorylated by mitogen-activated protein kinase interacting kinases 1 and 2 (MNK1/2) on Ser209. So, MNK1/2 inhibitors could decrease the level of p-eIF4E and regulate tumor-associated signaling pathways. A series of pyridone-aminal derivatives were synthesized and evaluated as MNK1/2 inhibitors. Several compounds exhibited great inhibitory activity against MNK1/2 and selected compounds showed moderate to excellent anti-proliferative potency against hematologic cancer cell lines. In particular, compound 42i (MNK1 IC50 = 7.0 nM; MNK2 IC50 = 6.1 nM) proved to be the most potent compound against TMD-8 cell line with IC50 value of 0.91 µM. Furthermore, 42i could block the phosphorylation level of eIF4E in CT-26 cell line, and 42i inhibited the tumor growth of CT-26 allograft model significantly. These results indicated that compound 42i was a promising MNK1/2 inhibitor for the potent treatment of colon cancer.

Long non-coding RNA HOX transcript antisense RNA (HOTAIR) suppresses the angiogenesis of human placentation by inhibiting vascular endothelial growth factor A expression.

HOX transcript antisense RNA (HOTAIR) is a long non-coding RNA located within the Homeobox C (HOXC) gene cluster on chromosome 12. Previous studies have revealed that HOTAIR is overexpressed in many types of cancers and is associated with metastasis and poor survival rates; however, few reports have mentioned the relationship between HOTAIR and angiogenesis of the human placenta. The aim of the present study was to investigate the correlation between HOTAIR and vascular endothelial growth factor (VEGF) A in the human placenta. HOTAIR levels decreased significantly in human placenta with increasing gestational age, and were negatively correlated with VEGFA levels. Invitro assays revealed that HOTAIR overexpression suppressed the proliferation, migration, invasion and tube formation of human umbilical vein endothelial cells (HUVECs); however, inhibition of HOTAIR had the opposite effects. Furthermore, VEGFA overexpression reversed the inhibitory effect of HOTAIR on the proliferation, migration, invasion and tube formation of HUVECs. In addition, overexpression of HOTAIR significantly inhibited VEGFA expression. Notably, a luciferase reporter assay found that HOTAIR inhibited VEGFA transcription by directly targeting the VEGFA promoter. Together, these results suggest that HOTAIR plays an important role in suppressing angiogenesis of the human placenta by inhibiting the expression of VEGFA; thus, HOTAIR may represent a potential therapeutic target for patients with human placental vascularisation abnormalities.

Targeting the immunity protein kinases for immuno-oncology.

With the rise of immuno-oncology, small-molecule modulators targeting immune system and inflammatory processes are becoming a research hotspot. This work mainly focuses on key kinases acting as central nodes in immune signaling pathways. Although over thirty small-molecule kinase inhibitors have been approved by FDA for the treatment of various cancers, only a few are associated with immuno-oncology. With the going deep of the research work, more and more immunity protein kinase inhibitors are approved for clinical trials to treat solid tumors and hematologic malignancies by FDA, which remain good prospects. Meanwhile, in-depth understanding of biological function of immunity protein kinases in immune system is pushing the field forward. This article focuses on the development of safe and effective small-molecule immunity protein kinase inhibitors and further work needs to keep the promises of these inhibitors for patients' welfare.

Targeting dipeptidyl peptidase 8 genes inhibits proliferation, migration and invasion by inhibition of cyclin D1 and MMP2MMP9 signal pathway in cervical cancer.

BACKGROUND: DPP8 is a member of the dipeptidyl peptidase IV family, which belongs to the S9b protease subfamily. It regulates cell proliferation, apoptosis, migration and invasion during cancer progression. METHODS: To investigate the role of DPP8 in cervical cancer, we examined DPP8 levels in cervical cancer tissues and cells. The localization of DPP8 was determined by immunofluorescence staining. Subsequently, SiHa and HeLa cells were treated with small interfering RNA (siRNA)-DPP8. We used cell cycle analysis, an 5-ethyl-2'-deoxyuridine assay proliferation assay and a cellular apoptosis assay to determine the effect of DPP8 on the proliferation and apoptosis of cervical cancer cells. We used a Transwell assay to assess the number of transfection cancer cells migrating through the matrix. A real-time polymerase chain reaction and western blot analysis were used to analyze the expression of related proteins and to determine the phenotype caused by the depletion or overexpression of DPP8 in cervical cancer cells. RESULTS: We observed that DPP8 was highly expressed in cervical cancer tissues and cells. DPP8 expression was observed in the cytosol and in the perinuclear area, as well as in the nuclei of cervical cancer cells. Notably, when cells were treated with siRNA-DPP8, the expression of BAX increased, and the expression of cyclin D1, Bcl-2, MMP2 and MMP9 was downregulated. In cervical cancer cell lines, silencing the expression of DPP8 not only suppressed the proliferation, migration and invasion of the cervical cancer cells, but also promoted cervical cancer cell apoptosis. CONCLUSIONS: The data obtained in the present study reveal that DPP8 promotes the progression of cervical cancer.

Lon Peptidase 2, Peroxisomal (LONP2) Contributes to Cervical Carcinogenesis via Oxidative Stress.

BACKGROUND Lon protease is responsible for degrading proteins injured by oxidation, and has 2 isoforms, located in mitochondria and peroxisomes. Recent research showed that Lon protease was upregulated in different types of human cancer, but the role of Lon peptidase 2, peroxisomal (LONP2) in cancer is not well understood. It is known, however, that in cancer biology, reduction-oxidation is one of the molecular mechanisms involved in tumorigenesis. MATERIAL AND METHODS Oncomine databases and tissue microarrays, initially using immunohistochemistry, were used to analyze LONP2 expression in cervical cancer. In order to uncover the biologic functions and mechanism(s) underlying LONP2 in cervical tumorigenesis, we downregulated the expression of LONP2 using 2 siRNAs transduced in HeLa and SiHa cells. CCK8 assays were performed to evaluate cell viability. Cell cycle and apoptosis assays were used to determine cell growth. Cell migration and invasion assays were used to study changes in cell migration and invasion capacity. Immunofluorescence and flow cytometry were performed to analyze the changes in ROS production. RESULTS We found that the expression of LONP2 was significantly upregulated in cervical cancer, and there was a significant association with pathology type, pathology grade, and clinical stage, but not with age or lymph node metastasis. Moreover, we demonstrated that knocking down LONP2 in HeLa and SiHa cells reduced cell proliferation, cell cycle, apoptosis, migration, invasion, and oxidative stress levels. CONCLUSIONS Our findings suggest that LONP2 promotes cervical tumorigenesis via oxidative stress and may be a potential biomarker and therapeutic target in cervical cancer.

miR­203 contributes to pre­eclampsia via inhibition of VEGFA expression.

Pre-eclampsia (PE) is a common but complex condition that can occur in pregnancy. It is estimated to affect 3-8% of pregnancies worldwide. PE development is thought to be multifactorial and to involve the dysregulation of microRNA (miR) expression. However, the precise mechanisms of PE development remain unclear. The present study aimed to illustrate the association between miR­203 expression and PE development in samples of human placenta collected from mothers with (n=18) and without (n=20) PE. It was demonstrated that miR­203 expression was significantly increased in the PE placenta compared with the normal placenta samples, while the expression of vascular endothelial growth factor A (VEGFA) was decreased. In vitro experiments revealed that miR­203 overexpression significantly downregulated VEGFA expression and inhibited the proliferation, migration and invasion ability of HTR­8/SVneo cells. Suppression of miR­203 expression alleviated these effects. A luciferase reporter assay confirmed the interaction of the 3'­untranslated region of VEGFA with miR­203. Thus, miR­203 may have significant contribution to the development of PE by targeting VEGFA in the human placenta and may have potential as a biomarker or therapeutic target in the treatment of PE.

MiR-203 Participates in Human Placental Angiogenesis by Inhibiting VEGFA and VEGFR2 Expression.

Angiogenesis during placentation is of great significance in maintaining normal pregnancy. However, the molecular mechanisms of this process are not clear. It has been reported that miR-203 plays a critical role in the development and progression of many tumors but not focused on the relationship between miR-203 and placental angiogenesis. The present study aims to illustrate the correlation between miR-203 and vascular endothelial growth factor (VEGFA)/vascular endothelial growth factor receptors 2 (VEGFR2) in human placenta and human umbilical vein endothelial cells (HUVECs) obtained from 40 samples. Samples of human placenta were collected based on gestation age, which was divided into early preterm (n = 10), late preterm (n = 12), and term (n = 18). In this work, we demonstrated that the expression of miR-203 decreased significantly in the placenta according to the gestation age, in contrast, the expression of VEGFA and VEGFR2 increased accordingly. In vitro experiments revealed that overexpression of miR-203 not only suppressed the proliferation, migration, invasion, and tube formation of HUVECs but also affected the expression of VEGFA and VEGFR2. Furthermore, inhibition of miR-203 expression showed equally apparent positive effects on HUVECs. In conclusion, our study suggests that miR-203 plays an important role in regulating placental angiogenesis through inhibiting the expression of VEGFA and VEGFR2, thus miR-203 may represent a potential therapeutic target for patients with abnormal formation of blood vessels in the placenta.