Upregulation of GRIM-19 suppresses the growth of oral squamous cell carcinoma in vitro and in vivo

The multifaceted role of STAT3 pathway and its implication as a potential therapeutic target in oral cancer

Oral cancer is one of the leading causes of cancer-related deaths, and it has become a matter of serious concern due to the alarming rise in its incidence rate worldwide. Despite recent advancements in oral cancer treatment strategies, there are no significant improvements in patient's survival rate. Among the numerous cell signaling pathways involved in oral cancer development and progression, STAT3 is known to play a multifaceted oncogenic role in shaping the tumor pathophysiology. STAT3 hyperactivation in oral cancer contributes to survival, proliferation, invasion, epithelial to mesenchymal transition, metastasis, immunosuppression, chemoresistance, and poor prognosis. A plethora of pre-clinical and clinical studies have documented the role of STAT3 in the initiation and development of oral cancer and showed that STAT3 inhibition holds significant potential in the prevention and treatment of this cancer. However, to date, targeting STAT3 activation mainly involves inhibiting the upstream signaling molecules such as JAK and IL-6 receptors. The major challenge in targeting STAT3 lies in the complexity of its phosphorylation- and dimerization-independent functions, which are not affected by disrupting the upstream regulators. The present review delineates the significance of the STAT3 pathway in regulating various hallmarks of oral cancer. In addition, it highlights the STAT3 inhibitors identified to date through various preclinical and clinical studies that can be employed for the therapeutic intervention in oral cancer treatment.

The effect of a gene associated with retinoid-interferon-induced mortality 19 (GRIM-19) on STAT3-induced gene expression in renal carcinoma

This study aimed to investigate the exact regulatory mechanisms of retinoid-interferon-induced mortality 19 (GRIM-19) in renal carcinoma. Tumour tissue samples from patients with renal carcinoma (n = 30, there were seven cases of Stage I, eight cases of Stage II, eight cases of Stage III, seven cases of Stage IV) and control subjects were selected from adjacent normal tissue (n = 10). Real-time quantitative PCR and western blotting were used to assess the level of GRIM-19, signal transducer and activator of transcription-3 (STAT3) and its downstream molecules. CD31 was detected by immunohistochemistry. The MTT assay was used to measure cell proliferation. The amount of apoptosis cells was analysed by Flow cytometry. The results showed that expression of GRIM-19 was decreased in renal carcinoma. However, in tumour tissue, STAT3 and its downstream signalling molecules showed the higher expression compared with control. Overexpression of GRIM-19, inhibited tumour growth apoptosis by mediating activators of STAT3 signal. In addition, interferon-β and all-trans-retinoic acid inhibited the renal carcinoma cell growth and induced apoptosis, and effect of drug combinations was particularly evident. In conclusion, GRIM-19 expression is associated with hyperactivation of STAT3-induced gene expression in renal carcinoma.

Grim-19 expressed by recombinant adenovirus for esophageal neoplasm target therapy

Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EA) are the two most common types of esophageal cancer, which is the sixth highest cause of cancer‑associated mortality and the eighth most common cancer worldwide. Gene associated with retinoid‑interferon (IFN)‑induced mortality‑19 (Grim‑19) is reported to be a cell death activator that may be used to define mechanisms involved in IFN‑β‑ and retinoic acid‑induced cell death and apoptosis in a number of tumor cell lines. The present study constructed a recombinant adenovirus expressing Grim‑19 (rAd‑Grim‑19) and investigated its therapeutic outcomes in ESCC cells and tumor‑bearing mice. Grim‑19 expression was detected in EC‑109 (ESCC) cells by reverse transcription‑quantitative polymerase chain reaction and western blot analysis. Tumor cell death and apoptosis induced by rAd‑Grim‑19 in EC‑109 cells were analyzed by flow cytometry. The inhibitory effects of rAd‑Grim‑19 on EC‑109 growth were determined by MTT assays. Furthermore, the therapeutic effects of rAd‑Grim‑19 were investigated in EC‑109‑bearing mice. The results demonstrated that Grim‑19 mRNA and protein expression was downregulated in EC‑109 esophageal carcinoma cells compared with Het‑1A normal esophageal epithelial cells. In addition, EC‑109 cells exhibited a significant reduction in tumor cell growth in the rAd‑Grim‑19 group compared with the control groups. Furthermore, rAd‑Grim‑19 increased EC‑109 cell apoptosis compared with the control group. These results indicated that rAd-Grim-19 may regulate tumor cell growth and apoptosis. Additionally, the results demonstrated that rAd‑Grim‑19 led to beneficial outcomes and prolonged the survival of esophageal tumor‑bearing mice. In conclusion, the present study demonstrated that rAd‑Grim‑19 may have potential as an antitumor agent for esophageal neoplasms and may therefore be beneficial for patients with esophageal neoplasms.

GRIM-19 Restricts HCV Replication by Attenuating Intracellular Lipid Accumulation

Gene-associated with retinoid-interferon-induced mortality 19 (GRIM-19) targets multiple signaling pathways involved in cell death and growth. However, the role of GRIM-19 in the pathogenesis of hepatitis virus infections remains unexplored. Here, we investigated the restrictive effects of GRIM-19 on the replication of hepatitis C virus (HCV). We found that GRIM-19 protein levels were reduced in HCV-infected Huh7 cells and Huh7 cells harboring HCV replicons. Moreover, ectopically expressed GRIM-19 caused a reduction in both intracellular viral RNA levels and secreted viruses in HCVcc-infected cell cultures. The restrictive effect on HCV replication was restored by treatment with siRNA against GRIM-19. Interestingly, GRIM-19 overexpression did not alter the level of phosphorylated STAT3 or its subcellular distribution. Strikingly, forced expression of GRIM-19 attenuated an increase in intracellular lipid droplets after oleic acid (OA) treatment or HCVcc infection. GRIM-19 overexpression abrogated fatty acid-induced upregulation of sterol regulatory element-binding transcription factor-1 (SREBP-1c), resulting in attenuated expression of its target genes such as fatty acid synthase (FAS) and acetyl CoA carboxylase (ACC). Treatment with OA or overexpression of SREBP-1c in GRIM-19-expressing, HCVcc-infected cells restored HCV replication. Our results suggest that GRIM-19 interferes with HCV replication by attenuating intracellular lipid accumulation and therefore is an anti-viral host factor that could be a promising target for HCV treatment.

Expression of GRIM-19 in adenomyosis and its possible role in pathogenesis

OBJECTIVE

To study the expression of the gene associated with retinoid-interferon (IFN)-induced mortality 19 (GRIM-19) in the endometrial tissue of patients with adenomyosis and to describe the possible pathogenic mechanisms of this phenomenon.

DESIGN

Experimental study using human samples and cell lines.

SETTING

University-affiliated hospital.

PATIENT(S)

Ectopic and eutopic endometrial tissues were obtained from 30 patients with adenomyosis, whereas normal endometrial specimens were obtained from 10 control patients without adenomyosis.

INTERVENTION(S)

Patients with rapid pathology report-confirmed adenomyosis were recruited, and eutopic and ectopic endometrial tissue samples were collected from patients who had undergone hysterectomies by either the transabdominal or laparoscopic method at Qilu Hospital. Normal endometrial tissue was collected from a group of control patients without adenomyosis.

MAIN OUTCOME MEASURE(S)

Immunohistochemistry (IHC) was performed to evaluate the expression of GRIM-19, phospho-signal transducer and activator of transcription 3 (Y705) (Y705) (pSTAT3(Y705)), and vascular endothelial growth factor (VEGF) in endometrial tissue samples. The protein levels of GRIM-19, pSTAT3(Y705), STAT3, and VEGF were detected by Western blot. Apoptosis in endometrial specimens was assayed by TUNEL. Immunohistochemistry with an antibody directed against CD34 was performed to detect new blood vessels in the endometrial tissue. GRIM-19 small interfering RNA and a recombinant plasmid carrying GRIM-19 were constructed to evaluate the effects of GRIM-19 on the downstream factors pSTAT3(Y705), STAT3, and VEGF in Ishikawa cells.

RESULT(S)

The expression of GRIM-19 was down-regulated in the eutopic endometria of patients with adenomyosis compared with the endometria of patients in the control group, and it was further reduced in the endometrial glandular epithelial cells of adenomyotic lesions. Apoptosis was reduced in the eutopic endometrium compared with the control group, and it was significantly reduced in ectopic endometrial tissues. In addition, the ectopic and eutopic endometria of patients with adenomyosis displayed a much higher microvessel density. In the eutopic and ectopic endometria of patients with adenomyosis, the expression levels of pSTAT3(Y705) and VEGF were significantly higher than in the controls. Furthermore, down-regulation of GRIM-19 in Ishikawa cells significantly promoted the activation of both pSTAT3(Y705) and its dependent gene VEGF.

CONCLUSION(S)

Aberrant expression of GRIM-19 may be associated with adenomyosis through the regulation of apoptosis and angiogenesis.