Protease nexin-1 prevents growth of human B cell lymphoma via inhibition of sonic hedgehog signaling

Targeting cancer hallmark vulnerabilities in hematologic malignancies by interfering with Hedgehog/GLI signaling

Understanding the genetic alterations, disrupted signaling pathways, and hijacked mechanisms in oncogene-transformed hematologic cells is critical for the development of effective and durable treatment strategies against liquid tumors. In this review, we focus on the specific involvement of the Hedgehog (HH)/GLI pathway in the manifestation and initiation of various cancer features in hematologic malignancies, including multiple myeloma, T- and B-cell lymphomas, and lymphoid and myeloid leukemias. By reviewing canonical and noncanonical, Smoothened-independent HH/GLI signaling and summarizing preclinical in vitro and in vivo studies in hematologic malignancies, we elucidate common molecular mechanisms by which HH/GLI signaling controls key oncogenic processes and cancer hallmarks such as cell proliferation, cancer stem cell fate, genomic instability, microenvironment remodeling, and cell survival. We also summarize current clinical trials with HH inhibitors and discuss successes and challenges, as well as opportunities for future combined therapeutic approaches. By providing a bird's eye view of the role of HH/GLI signaling in liquid tumors, we suggest that a comprehensive understanding of the general oncogenic effects of HH/GLI signaling on the formation of cancer hallmarks is essential to identify critical vulnerabilities within tumor cells and their supporting remodeled microenvironment, paving the way for the development of novel and efficient personalized combination therapies for hematologic malignancies.

METTL3 enhances the effect of YTHDF1 on NEDD1 mRNA stability by m6A modification in diffuse large B-cell lymphoma cells

AIM

Diffuse large B-cell lymphoma (DLBCL) remains the most frequent subpopulation of lymphoma, and N6-methyladenosine (m6A) was implicated in the DLBCL progression. Herein, we sought to decipher the m6A-asociated mechanism of NEDD1 in DLBCL development.

METHODS

The NEDD1 expression profile in DLBCL was assessed by quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot. NEDD1 was artificially downregulated or upregulated in DLBCL cells, followed by EdU, Transwell assays and flow cytometry. The Hedgehog pathway activity was assayed by a dual-luciferase assay. The m6A methylation of NEDD1 in DLBCL was assessed by meRIP-qPCR, and the regulatory mechanism of METTL3 on NEDD1 was validated. The LDH assay was conducted to examine the impact of CD8+ T cells on DLBCL cells. The DLBCL cells were administrated into mice to evaluate the tumorigenic activity and ki-67 activity in tumor tissues.

RESULTS

NEDD1 was overexpressed in DLBCL. Depletion of NEDD1 inhibited the aggressiveness of SU-DHL-8 and OCI-LY1 cells, whereas overexpression of NEDD1 expedited the aggressiveness of SU-DHL-8 and OCI-LY1 cells. METTL3 promoted NEDD1 translation in an m6A-dependent manner via YTHDF1. Depletion of METTL3 inhibited SU-DHL-8 and OCI-LY1 cell activity through regulation of NEDD1. NEDD1 reversed the repressive effect of METTL3 loss on the aggressiveness of SU-DHL-8 and OCI-LY1 cells. NEDD1 activated the Hedgehog signaling to promote immune escape of DLBCL.

CONCLUSIONS

METTL3 promotes translation of NEDD1 via YTHDF1-depedndent m6A modification, thereby activating the Hedgehog signaling pathway to promote immune escape of DLBCL cells.

NFYB potentiates STK33 activation to promote cisplatin resistance in diffuse large B-cell lymphoma

BACKGROUND

The aberrant expression of serine/threonine kinase 33 (STK33) has been implicated in cancers. However, its clinical significance and biological functions in diffuse large B cell lymphoma (DLBCL) remain largely unknown. In the present investigation, we delineated the expression of STK33 in DLBCL and its function in cisplatin resistance.

METHODS

First, genes associated with drug resistance as well as occurrence in DLBCL were analyzed by bioinformatics, followed by correlation analysis between STK33 expression and clinical baseline information of patients with DLBCL. Further, cisplatin-resistant DLBCL cell lines were constructed, and changes in cell sensitivity to cisplatin treatment were examined after interfering the expression of STK33 in parental cells as well as in drug-resistant cells, respectively. Subsequently, the downstream signaling pathways of STK33 were analyzed. Finally, the upstream regulatory mechanism of STK33 was predicted by bioinformatics as well as experimentally validated.

RESULTS

STK33 was overexpressed in the patients with DLBCL as well as in cisplatin-resistant DLBCL cells, and knockdown of STK33 significantly promoted sensitivity of resistant cells to cisplatin. Moreover, our further analysis revealed that STK33 promoted cisplatin resistance in DLBCL by activating the Hedgehog signaling pathway. We found in subsequent experiments that nuclear transcription factor Y subunit beta (NFYB) can bind to the STK33 promoter and thus promote STK33 expression.

CONCLUSIONS

The transcription factor NFYB expedites the transcription of SYK33 by binding to the STK33 promoter, thereby activating the Hedgehog signaling pathway in DLBCL cells, which in turn promotes the resistance of DLBCL cells to cisplatin.

Protease nexin-1 protects against Alzheimer's disease by regulating the sonic hedgehog signaling pathway

Objective: To explore the role of protease nexin-1 (PN-1) in Alzheimer's disease (AD) via the sonic hedgehog (SHH) pathway.Methods: PN-1 lentiviral activation particles were injected into APP/PS1 transgenic AD and wild-type (WT) mice; these mice were subjected to the Morris water maze test, followed by ELISA, thioflavin S staining and NeuN-TUNEL dual staining. HT22 cells were induced with Aβ_1-42 and treated with PN-1 siRNA and/or cyclopamine (an SHH signaling inhibitor). The cells were then subjected to MTT and Annexin V-FITC/PI analyses. qRT-PCR and Western blotting were conducted to measure mRNA and protein expression.Results: The escape latency of the APP/PS1 transgenic AD mice was extended with a decreased number of platform crossings; in addition, increased Aβ deposits, Aβ_1-42 levels and hippocampal neuron apoptosis were observed in the brain tissues of AD mice. However, these changes were improved by PN-1 lentiviral activation particles. In addition, PN-1 overexpression inhibited the SHH pathway in AD mice. Moreover, PN-1 overexpression abolished the Aβ_1-42-induced activation of the SHH pathway in HT22 cells. In addition, Aβ_1-42 induction resulted in an increased apoptotic rate and decreased cell viability of HT22 cells; however, these effects were reversed by PN-1 or cyclopamine. Compared with that in the PN-1 siRNA + cyclopamine + Aβ_1-42 group, apoptosis of HT22 cells in the cyclopamine + Aβ_1-42 group was reduced and cell viability was improved.Conclusion: PN-1, by blocking SHH pathway, reduced apoptosis of hippocampal neurons to improve spatial learning and memory ability, thereby playing a protective role in AD.

Chidamide Inhibits Glioma Cells by Increasing Oxidative Stress via the miRNA-338-5p Regulation of Hedgehog Signaling

Objective

Chidamide has a broad spectrum of antitumor activity but its function on glioma remains unknown. The increase of reactive oxygen species (ROS) and reactive nitrogen species (RNS) may control glioma risk by promoting its apoptosis and necrosis. Hedgehog pathway is crucial to glioma cell proliferation and controls ROS production. We aimed to explore the effects of chidamide on the levels of miR-338-5p (glioma cell inhibitor), which may regulate Hedgehog signaling, resulting in the changes of RNS. Materials and Methods. Migration and invasion activities of glioma cells were measured by using the Transwell chamber assay. The expression levels of Sonic Hedgehog (Shh), Indian Hedgehog (Ihh), Desert Hedgehog (Dhh), miR-338-5p, and related molecules were detected by using real-time PCR (RT-PCR) and or Western Blot in U87 and HS683 glioma cells. The effects of chidamide on these molecules were measured by using the miR-338-5p inhibitor or mimics in U87 and HS683 glioma cell lines. ROS and RNS were measured by DCF DA and DAF-FM DA fluorescence. Biomarkers of oxidative stress were measured by using a corresponding kit. Apoptosis and necrosis rates were measured by using flow cytometry.

Results

Chidamide inhibited the growth rate, migration, and invasion of human malignant glioma cells and increased the level of miR-338-5p. miR-338-5p inhibitor or mimics increased or inhibited the growth rate of U87 and HS683 glioma cells. Chidamide inhibited the levels of Shh, Ihh, migration protein E-cadherin, and invading protein MMP-2. The increase in the level of Shh and Ihh led to the reduction in the ROS and RNS levels. miR-338-5p inhibitor or mimics also showed a promoting or inhibitory function for the levels of Shh and Ihh. Furthermore, miR-338-5p mimics and inhibitor inhibited or promoted the migration and invasion of the glioma cells (P < 0.05). Evaluated levels of miR-338-5p increased oxidative stress level and apoptosis and necrosis rate by regulating the levels of biomarkers of oxidative stress (P < 0.05). Evaluated levels of miR-338-5p increased oxidative stress level and apoptosis and necrosis rate by regulating the levels of biomarkers of oxidative stress (

Conclusion

Chidamide inhibits glioma cells by increasing oxidative stress via the miRNA-338-5p regulation of Hedgehog signaling. Chidamide may be a potential drug in the prevention of glioma development.