HSPA12B: a novel facilitator of lung tumor growth

PI3Kα inhibitor GNE-493 triggers antitumor immunity in murine lung cancer by inducing immunogenic cell death and activating T cells

Phosphatidylinositol 3-kinase (PI3K) is frequently hyperactivated in cancer, playing pivotal roles in the pathophysiology of both malignant and immune cells. The impact of PI3K inhibitors on the tumor microenvironment (TME) within lung cancer remains largely unknown. In this study, we explored the regulatory effects of GNE-493, an innovative dual inhibitor of PI3K and mammalian target of rapamycin (mTOR), on the TME of lung cancer. First, through the analysis of The Cancer Genome Atlas-lung squamous cell carcinoma (LUSC) cohort, we found PIK3CA to be related to CD8 T cells, which may affect the overall survival rate of patients by affecting CD8 function. We herein demonstrated that GNE-493 can significantly inhibit tumor cell proliferation and promote cell apoptosis while increasing the expression of the immunogenic death-related molecules CRT and HSP70 using in vitro cell proliferation and apoptosis experiments on the murine KP lung cancer cell line and human A549 lung cancer cell line. Next, through the establishment of an orthotopic tumor model in vivo, it was found that after GNE-493 intervention, the infiltration of CD4+ and CD8+ T cells in mouse lung tumor was significantly increased, and the expression of CRT in tumors could be induced to increase. To explore the mechanisms underlying PI3K inhibition-induced changes in the TME, the gene expression differences of T cells in the control group versus GNE-493-treated KP tumors were analyzed by RNA-seq, and the main effector pathway of anti-tumor immunity was identified. The IFN/TNF family molecules were significantly upregulated after GNE-493 treatment. In summary, our findings indicate that GNE-493 promotes immunogenic cell death in lung cancer cells, and elucidates its regulatory impact on molecules associated with the adaptive immune response. Our study provides novel insights into how PI3K/mTOR inhibitors exert their activity by modulating the tumor-immune interaction.

Physiologic and pathophysiologic roles of AKAP12

A kinase anchoring protein (AKAP) 12 is a scaffolding protein that improves the specificity and efficiency of spatiotemporal signal through assembling intracellular signal proteins into a specific complex. AKAP12 is a negative mitogenic regulator that plays an important role in controlling cytoskeletal architecture, maintaining endothelial integrity, regulating glial function and forming blood-brain barrier (BBB) and blood retinal barrier (BRB). Moreover, elevated or reduced AKAP12 contributes to a variety of diseases. Complex connections between AKAP12 and various diseases including chronic liver diseases (CLDs), inflammatory diseases and a series of cancers will be tried to delineate in this paper. We first describe the expression, distribution and physiological function of AKAP12. Then we summarize the current knowledge of different connections between AKAP12 expression and various diseases. Some research groups have found paradoxical roles of AKAP12 in different diseases and further confirmation is needed. This paper aims to assess the role of AKAP12 in physiology and diseases to help lay the foundation for the design of small molecules for specific AKAP12 to correct the pathological signal defects.

The expression of heat shock protein A12B (HSPA12B) in non-Hodgkin's lymphomas

Background

Heat shock protein A12B (HSPA12B) plays a considerable protective role for cells, tissues, and organs against various noxious conditions. However, the expression of HSPA12B in cancer biology remains controversial. This study aimed to investigate the expression of HSPA12B and its role in cell adhesion mediated drug resistance (CAM-DR) of non-Hodgkin’s lymphoma (NHL).

Methods

In this study, the expression of HSPA12B in NHL was determined by immunohistochemical, and the effect of HSPA12B expression on the prognosis of NHL was analyzed by Kaplan–Meier curves. Then, the transfection technique was used to research the effect of HSPA12B in cell apoptosis. The most important was to study the expression changes of HSPA12B in the adhesion model and the effect of overexpression of HSPA12B on CAM-DR.

Results

We analyzed the relationship between the expression levels of HSPA12B and clinical parameters in NHL. The expression of HSPA12B was directly related to the different NHL variants. We overexpressed HSPA12B in 2 NHL cell lines and found a subsequent reduction in apoptosis. More specifically, we used an adhesion assay to demonstrate that HSPA12B expression was induced in NHL cells when they adhered to fibronectin (FN) or bone marrow stroma cells (BMSCs). Finally, it was revealed that HSPA12B overexpression enhances CAM-DR.

Conclusions

Our data suggest that HSPA12B may play a functional role in CAM-DR and is thus a potential novel target for NHL treatment.

MiR-325 Promotes Oxaliplatin-Induced Cytotoxicity Against Colorectal Cancer Through the HSPA12B/PI3K/AKT/Bcl-2 Pathway

BACKGROUND

Oxaliplatin is one of the most effective chemotherapeutic drugs used for the treatment of colorectal cancer (CRC). However, intervention that attenuates the resistance of oxaliplatin is still required in the treatment of CRC.

AIMS

To investigate the role of miR-325 in changing the oxaliplatin sensitivity to CRC cells.

METHODS

Expression of miR-325 in colorectal cancer tissues and cell lines was measured by using qRT-PCR analysis. Cytotoxicity of oxaliplatin to control or miR-325-overexpressed HT29 and SW480 cells was evaluated by CCK-8 assays. Luciferase reporter assay was used to confirm the regulation of miR-325 on HSPA12B. Flow cytometry was performed to detect the mitochondrial membrane potential and cell apoptosis.

RESULTS

Expression of miR-325 was decreased in colorectal cancer tissues and cell lines. However, overexpression of miR-325 can decrease the 50% inhibiting concentration of oxaliplatin to colorectal cancer cell lines HT29 and SW480. Mechanically, we confirmed that miR-325 targeted HSPA12B in colorectal cancer. Therefore, overexpression of miR-325 inhibited the phosphorylation of PI3K and AKT and decreased the expression of Bcl-2 to promote the oxaliplatin-induced mitochondrial apoptosis in colorectal cancer.

CONCLUSIONS

MiR-325 sensitizes the colorectal cancer cells to oxaliplatin-induced cytotoxicity through the HSPA12B/PI3K/AKT/Bcl-2 pathway.

Characterization of the Impact of Density Gradient Centrifugation on the Profile of the Pig Sperm Transcriptome by RNA-Seq

RNA-Seq data from human semen suggests that the study of the sperm transcriptome requires the previous elimination from the ejaculates of somatic cells carrying a larger load of RNA. Semen purification is also carried to study the sperm transcriptome in other species including swine and it is often done by density gradient centrifugation to obtain viable spermatozoa from fresh ejaculates or artificial insemination doses, thereby limiting the throughput and remoteness of the samples that can be processed in one study. The aim of this work was to evaluate the impact of purification with density gradient centrifugation by BoviPure^TM on porcine sperm. Four boar ejaculates were purified with BoviPure^TM and their transcriptome sequenced by RNA-Seq was compared with the RNA-Seq profiles of their paired non-purified sample. Seven thousand five hundred and nineteen protein coding genes were identified. Correlation, cluster, and principal component analysis indicated high—although not complete—similarity between the purified and the paired non-purified ejaculates. 372 genes displayed differentially abundant RNA levels between treatments. Most of these genes had lower abundances after purification and were mostly related to translation, transcription and metabolic processes. We detected a significant change in the proportion of genes of epididymal origin within the differentially abundant genes (1.3%) when compared with the catalog of unaltered genes (0.2%). In contrast, the proportion of testis-specific genes was higher in the group of unaltered genes (4%) when compared to the list of differentially abundant genes (0%). No proportion differences were identified for prostate, white blood, lymph node, tonsil, duodenum, skeletal muscle, liver, and mammary gland. Altogether, these results suggest that the purification impacts on the RNA levels of a small number of genes which are most likely caused by the removal of epididymal epithelial cells but also premature germinal cells, immature or abnormal spermatozoa or seminal exosomes with a distinct load of RNAs.

The expression profiles and prognostic values of HSP70s in hepatocellular carcinoma

Background

The HSP70 family of heat shock protein plays a critical role in protein synthesis and transport to maintain protein homeostasis. Several studies have indicated that HSP70s are related to the development and occurrence of various cancers.

Methods

The relationship between the overall survival rate of hepatocellular carcinoma patients and the expression of 14 HSP70s from multiple databases, such as TCGA, ONCOMINE, cBioPortal was investigated. Western Blot and PCR were used to evaluate HSPA4 and HSPA14 expressions in various HCC cells to identify suitable cell lines for further experiments .Wound-healing assays, Transwell assays and EdU assays were used to verify the effects of HSPA4 and HSPA14 on the function of hepatocellular carcinoma cells, and statistical analysis was performed.

Results

Hepatocellular carcinoma tissues significantly expressed the 14 HSP70s compared to the normal samples. Besides, the high HSPA1A, HSPA1B, HSPA4, HSPA5, HSPA8, HSPA13, and HSPA14 expressions were inversely associated with the overall survival rate of patients, tumor grade, and cancer stage. A PPI regulatory network was constructed using the 14 HSP70s proteins with HSPA5 and HSPA8 at the network center. Univariate and multivariate analyses showed that HSPA4 and HSPA14 could be independent risk factors for the prognosis of hepatocellular carcinoma patients. Cell experiments have also confirmed that reducing HSPA4 and HSPA14 expressions can inhibit the invasion, metastasis, and proliferation of hepatocellular carcinoma cells.

Conclusions

Therefore, the HSP70s significantly influence the occurrence and development of hepatocellular carcinoma. For instance, HSPA4 and HSPA14 can be novel therapeutic targets and prognostic biomarkers for hepatocellular carcinoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01987-9.

Endothelial cell HSPA12B and yes-associated protein cooperatively regulate angiogenesis following myocardial infarction

Angiogenesis is essential for cardiac functional recovery after myocardial infarction (MI). HSPA12B is predominately expressed in endothelial cells and required for angiogenesis. Yes-associated protein (YAP) plays an important role in tumor angiogenesis. This study investigated the cooperative role of HSPA12B and YAP in angiogenesis after MI. Silencing of either HSPA12B or YAP impaired hypoxia-promoted endothelial cell proliferation and angiogenesis. Deficiency of HSPA12B suppressed YAP expression and nuclear translocation after hypoxia. Knockdown of YAP attenuated hypoxia-stimulated HSPA12B nuclear translocation and abrogated HSPA12B-promoted endothelial cell angiogenesis. Mechanistically, hypoxia induced an interaction between endothelial HSPA12B and YAP. ChIP assay showed that HSPA12B is a target gene of YAP/transcriptional enhanced associated domain 4 (TEAD4) and a coactivator in YAP-associated angiogenesis. In vivo studies using the MI model showed that endothelial cell-specific deficiency of HSPA12B (eHspa12b-/-) or YAP (eYap-/-) impaired angiogenesis and exacerbated cardiac dysfunction compared with WT mice. MI increased YAP expression and nuclear translocation in WT hearts but not eHspa12b-/- hearts. HSPA12B expression and nuclear translocation were upregulated in WT MI hearts but not eYap-/- MI myocardium. Our data demonstrate that endothelial HSPA12B is a target and coactivator for YAP/TEAD4 and cooperates with YAP to regulate endothelial angiogenesis after MI.

HSPA12B Secreted by Tumor-Associated Endothelial Cells Might Induce M2 Polarization of Macrophages via Activating PI3K/Akt/mTOR Signaling

Purpose

The intratumoral microenvironment of head and neck squamous cell carcinoma (HNSC) is highly immunosuppressive. In this study, we explored the potential functional role of HSPA12B secreted by tumor-associated endothelial cells (TECs) in M2 polarization of macrophages.

Materials and Methods

Bulk-seq data from TCGA-HNSC and single-cell RNA-seq data from GSE103322 (with over 5000 cells from 18 primary HNSC cases) were used for bioinformatic analysis. RAW264.7 cell line was used for in vitro studies.

Results

TECs in HNSC had significantly higher expression and secretion of HSPA12B, compared to normal human umbilical vein endothelial cells (HUVECs). Exogenous HSPA12B treatment increased the expression of M2 macrophage marker CD163 and CD206 on RAW264.7 cells in a dose-dependent manner but had no significant influence on CD86, an M1 macrophage marker. OLR1, a known receptor of HSP70 proteins, was specifically expressed in tumor-associated macrophages (TAMs) in HNSC. OLR1 knockdown significantly impaired HSPA12B uptake by RAW264.7 cells and weakened HSPA12B-induced CD163 and CD206 upregulation. HSPA12B treatment increased the expression of p-PI3K, p-Akt and p-mTOR in a dose-dependent manner in RAW264.7 cells. OLR1 inhibition and LY294002 treatment significantly weakened the effects HSPA12B on activating the PI3K/Akt/mTOR signaling and M2 marker expression.

Conclusion

Based on these findings, we speculated that aberrantly expressed and secreted HSPA12B by TECs could be taken by macrophages partly via OLR1, leading to subsequent activation of the PI3K/Akt/mTOR signaling pathway and elevated expression of M2 markers. This mechanism shows a novel cross-talk between TECs and TAMs, which contributes to the intratumoral immunosuppressive microenvironment.

Alpha-lipoic acid inhibits proliferation and migration of human vascular endothelial cells through downregulating HSPA12B/VEGF signaling axis

Endothelial cells play essential roles in angiogenesis. Heat shock protein A12B (HSPA12B), a novel member of the multigene Hsp70 family, expresses specifically in endothelial cells. Alpha-lipoic acid (LA) has been used for the treatment of human diabetic complications for more than 20 years. However, little is known whether LA impacts endothelial proliferation and migration. To address these questions, primary human umbilical vein endothelial cells (HUVECs) were isolated and treated with LA. We found that LA reduced viable HUVECs but not caused LDH leakage and nuclear condensation, suggesting an inhibitory effect of LA on HUVEC proliferation. We also noticed that LA impeded wound closure of HUVEC monolayers. The expressions of C-Myc, VEGF, and eNOS and phosphorylation of focal adhesion kinase were reduced by LA. Moreover, LA decreased the expression of heat shock protein A12B (HSPA12B). Notably, overexpression of HSPA12B in endothelial cells prevented the LA-induced loss of VEGF. More importantly, HSPA12B overexpression attenuated the LA-induced inhibition of endothelial proliferation and migration. Collectively, the results demonstrated that LA inhibited proliferative and migratory abilities in human vascular endothelial cells through the downregulation of the HSPA12B/VEGF signaling axis. The data suggest that besides the treatment in diabetic complications, LA might represent a viable therapeutic potential for human diseases that involve high angiogenic activities such as cancers.

Alpha-lipoic acid inhibits lung cancer growth via mTOR-mediated autophagy inhibition

Lung cancer is the leading cause of cancer‐related death, and there remains a need for novel therapies for this malignancy. Here, we examined the effects of alpha‐lipoic acid (LA), a drug used for treating human diabetic complications, on lung cancer growth. We report that LA limited lung cancer growth in xenograft mice and reduced lung cancer A549 cell viability. We observed autophagy activation in human lung cancers, and report that LA inactivated autophagy in A549 cells. In addition, LA activated mammalian target of rapamycin (mTOR)/p70S6K signaling. Inhibition of mTOR with rapamycin reversed LA‐induced inactivation of autophagy and abolished LA‐induced suppression of A549 cell viability. Altogether, the data suggest that LA exerts an anti‐lung cancer effect through mTOR‐mediated inhibition of autophagy, and thus LA may have therapeutic potential for lung cancer management.

uc.454 Inhibited Growth by Targeting Heat Shock Protein Family A Member 12B in Non-Small-Cell Lung Cancer

Transcribed ultraconserved regions (T-UCRs) classified as long non-coding RNAs (Lnc-RNAs) are transcripts longer than 200-nt RNA with no protein-coding capacity. Previous studies showed that T-UCRs serve as novel oncogenes, or tumor suppressors are involved in tumorigenesis and cancer progressive. Nevertheless, the clinicopathologic significance and regulatory mechanism of T-UCRs in lung cancer (LC) remain largely unknown. We found that uc.454 was downregulated in both non-small-cell LC (NSCLC) tissues and LC cell lines, and the downregulated uc.454 is associated with tumor size and tumors with more advanced stages. Transfection with uc.454 markedly induced apoptosis and inhibited cell proliferation in SPC-A-1 and NCI-H2170 LC cell lines. Above results suggested that uc.454 played a suppressive role in LC. Heat shock protein family A member 12B (HSPA12B) protein was negatively regulated by uc.454 at the posttranscriptional level by dual-luciferase reporter assay and affected the expressions of Bcl-2 family members, which finally induced LC apoptosis. The uc.454/HSPA12B axis furthers our understanding of the molecular mechanisms involved in tumor apoptosis, which may potentially serve as a therapeutic target for lung carcinoma.

HSPA12B overexpression induces cisplatin resistance in non-small-cell lung cancer by regulating the PI3K/Akt/NF-κB signaling pathway

Although cisplatin (CDDP) is widely used for non-small-cell lung cancer (NSCLC) treatment, resistance remains a major problem that restricts its efficacy. Therefore, identification of drugs that reverse or prevent resistance to CDDP in NSCLC has been a focus of a number of studies. The results of the present study revealed the effect of heat shock protein family A member 12B (HSPA12B) overexpression on chemoresistance in A549 cells in vitro. The effect of HSPA12B overexpression on chemoresistance in mice bearing A549 xenografted tumors was then determined via stable HSPA12B transfection. Finally, the effects of HSPA12B overexpression on the phosphorylation of protein kinase B (Akt) and nuclear factor-κB inhibitor α (IκBα), and the expression of the anti-apoptotic protein B-cell lymphoma 2 (Bcl-2) and the pro-apoptotic protein cleaved caspase-3 were determined by western blot analysis. The results demonstrated that HSPA12B overexpression increased resistance to CDDP in NSCLC cells in vivo and in vitro by promoting cell growth and inhibiting CDDP-induced apoptosis. Mechanistically, this effect was mediated by the upregulation of phosphorylated (p-)Akt, p-IκBα and Bcl-2 and the downregulation of cleaved caspase-3. Therefore, the present study provides useful information pertaining to the identification and targeting of a CDDP-resistant population, and the development of potential therapeutics to improve the current treatment modalities in NSCLC.

Molecular chaperones in the acquisition of cancer cell chemoresistance with mutated TP53 and MDM2 up-regulation

Utilizing the TCGA PANCAN12 dataset we discovered that cancer patients with mutations in TP53 tumor suppressor and overexpression of MDM2 oncogene exhibited decreased survival post treatment. Interestingly, in the case of breast cancer patients, this phenomenon correlated with high expression level of several molecular chaperones belonging to the HSPA, DNAJB and HSPC families. To verify the hypothesis that such a genetic background may promote chaperone-mediated chemoresistance, we employed breast and lung cancer cell lines that constitutively overexpressed heat shock proteins and have shown that HSPA1A/HSP70 and DNAJB1/HSP40 facilitated the binding of mutated p53 to the TAp73α protein. This chaperone-mediated mutated p53–TAp73α complex induced chemoresistance to DNA damaging reagents, like Cisplatin, Doxorubicin, Etoposide or Camptothecin. Importantly, when the MDM2 oncogene was overexpressed, heat shock proteins were displaced and a stable multiprotein complex comprising of mutated p53-TAp73α-MDM2 was formed, additionally amplifying cancer cells chemoresistance. Our findings demonstrate that molecular chaperones aid cancer cells in surviving the cytotoxic effect of chemotherapeutics and may have therapeutic implications.