Effect of Diacerein on HOTAIR/IL-6/STAT3, Wnt/β-Catenin and TLR-4/NF-κB/TNF-α axes in colon carcinogenesis

Highlights

• MTT assay confirmed significant cytotoxic effect of diacerein in vitro.

• Annexin V results confirmed apoptotic effect of diacerein on cancer cells.

• Diacerein down-regulated tissue VEGF expression with paralleled anti-angiogenic impact.

• Diacerein regulated Wnt/β-Catenin pathway and modulated cellular tumorigenic modifications.

• Diacerein interrupted IL-6/STAT3/ lncRNA HOTAIR axis.

Abstract

Colorectal cancer (CRC) is a common malignancy with high mortality and poor prognosis. Diacerein (DIA) is an anti-inflammatory used for treatment of osteoarthritis. We delineated some underlying molecular mechanisms of DIA’s anti-carcinogenic effect in CRC using in vivo and in vitro models. Human Caco-2 cells were treated with DIA followed by MTT and Annexin V assays and CRC was experimentally induced using 1,2-dimethylhydrazine. DIA (50 mg/kg/day, orally) was administrated for 8 weeks. The MTT assay confirmed cytotoxic effect of DIA in vitro and Annexin V confirmed its apoptotic effect. DIA resulted in regression of tumour lesions with reduced colonic TLR4, NF-κB and TNF-α protein levels and down-regulated VEGF expression, confirming anti-angiogenic impact. DIA triggered caspase-3 expression and regulated Wnt/β-Catenin pathway, by apparently interrupting the IL-6/STAT3/ lncRNA HOTAIR axis. In conclusion, DIA disrupted IL-6/STAT3/ lncRNA HOTAIR axis which could offer an effective therapeutic strategy for the management of CRC.

Introduction

Colorectal cancer (CRC) is a common worldwide malignancy with about two-thirds of all diagnosed cases occurring in the more developed regions of the world. CRC originates in the epithelial cell lining of the colon or rectum. It is associated with a series of histopathological and molecular alterations that ultimately transform the normal colonic epithelium into an invasive carcinoma (Khan et al., 2018). Globally, CRC is the second most commonly diagnosed cancer in females and the third in males with 1.8 million newly diagnosed cases and almost 861,000 deaths annually (Su et al., 2019). Indeed, CRC represents the third most common cause of cancer-related mortality in both genders worldwide (Pervaiz et al., 2021).

The etiology of CRC is multifactorial, involving the interaction between various exogenous chemical and endogenous biological factors such as the individual’s diet, the genetic predisposition, the age, the extent of physical activity and smoking (Al-Ghafari et al., 2019). Interestingly, epidemiological studies have reported that the consumption of toxicants through diets rich in saturated fat plays a central role in the individual’s susceptibility to CRC, contributing to up to 80% of documented CRC cases (Harris et al., 2016). The current therapeutic strategies for CRC include surgery, chemotherapy and radiotherapy. Of note, surgery is suitable only at early stages of disease. For advanced stages, chemotherapy and radiotherapy are applied; however their use is accompanied by deleterious side effects, such as chemotherapy-induced organ toxicity (Kumar and Agnihotri, 2019). Therefore, it is imperative to search for alternative safe and effective anti-tumourigenic agents to combat CRC progression.

Diacerein (DIA) is an anti-inflammatory drug clinically prescribed for the treatment of osteoarthritis (El-Sherbiny et al., 2021). It is an anthraquinone derivative that shows non-steroidal pro-inflammatory cytokine inhibitor activity (Steinecker-Frohnwieser et al., 2014). The tumour environment is rich in pro-inflammatory cytokines which in turn promotes several oncogenic signalling pathways. Among these cytokines, Interleukin-6 (IL-6), which has received particular attention in the pathogenesis of various types of cancer via triggering downstream STAT3 signalling pathway (Xie et al., 2019), (Wang et al., 2018).

In this context, DIA has been reported to instigate apoptosis of breast cancer cells via inhibition of IL-6/STAT3 ( Bharti et al., 2016a). Therefore, targeting IL6/STAT3 axis could be a potential blueprint for cancer therapy. A recent study has demonstrated the anti-neoplastic efficacy of DIA in CRC through targeting IL-6/K-Ras/Notch/NF-κB p65, p-Akt/GSK3-β/β-catenin/cyclinD-1, and Nur77 (Abdel-Latif et al., 2022).

This report will investigate IL-6/STAT-3/HOTAIR lncRNA as an additional potential molecular target for DIA using 1,2-dimethylhydrazine-induced CRC model. Moreover, the involvement of TLR4/NF-κB/ TNF-α and Wnt/β-Catenin axes in anti-proliferative efficacy of DIA will also be investigated.