Nicotinic acetylcholine receptors in chemotherapeutic drugs resistance: An emerging targeting candidate

α5-nAChR/ADAM10 signaling mediates nicotine-related cutaneous melanoma progression via STAT3 activation

Skin cutaneous melanoma (SKCM) is the skin malignancy with the highest mortality rate, and its morbidity rate is on the rise worldwide. Smoking is an independent marker of poor prognosis in melanoma. The α5-nicotinic acetylcholine receptor (α5-nAChR), one of the receptors for nicotine, is involved in the proliferation, migration and invasion of SKCM cells. Nicotine has been reported to promote the expression of a disintegrin and metalloproteinase 10 (ADAM10), which is the key gene involved in melanoma progression. Here, we explored the link between α5-nAChR and ADAM10 in nicotine-associated cutaneous melanoma. α5-nAChR expression was correlated with ADAM10 expression and lower survival in SKCM. α5-nAChR mediated nicotine-induced ADAM10 expression via STAT3. The α5-nAChR/ADAM10 signaling axis was involved in the stemness and migration of SKCM cells. Furthermore, α5-nAChR expression was associated with ADAM10 expression, EMT marker expression and stemness marker expression in nicotine-related mice homograft tissues. These results suggest the role of the α5-nAChR/ADAM10 signaling pathway in nicotine-induced melanoma progression.

Nicotinic acetylcholine receptors in cancer: Limitations and prospects

Nicotinic acetylcholine receptors (nAChRs) have long been considered to solely mediate neurotransmission. However, their widespread distribution in the human body suggests a more diverse physiological role. Additionally, the expression of nAChRs is increased in certain cancers, such as lung cancer, and has been associated with cell proliferation, epithelial-to-mesenchymal cell transition, angiogenesis and apoptosis prevention. Several compounds that interact with these receptors have been identified as potential therapeutic agents. They have been tested as drugs for treating nicotine addiction, alcoholism, depression, pain and Alzheimer's disease. This review focuses on nAChR-mediated signalling in cancer, presenting opportunities for the development of innovative nAChR-based anticancer drugs. It displays the differences in expression of each nAChR subunit between normal and cancer cells for selected cancer types, highlighting their possible involvement in specific cases. Antagonists of nAChRs that could complement existing cancer therapies are summarised and critically discussed. We hope that this review will stimulate further research on the role of nAChRs in cancer potentially leading to innovative cancer therapies.

Downregulation of BUBR1 regulates the proliferation and cell cycle of breast cancer cells and increases the sensitivity of cells to cisplatin

Breast cancer (BC) is a significant tissue for women's health worldwide. The spindle assembly checkpoint protein family includes BUBR1 (Bub1-related kinase or MAD3/Bub1b). High expression of BUBR1 promotes cell cycle disorders, leading to cell carcinogenesis and cancer progression. However, the underlying molecular mechanism and the role of BUBR1 in BC progression are unclear. The published dataset was analyzed to evaluate the clinical relevance of BUBR1. BUBR1 was knocked down in BC cells using shRNA. The CCK-8 assay was used to measure the cell viability, and mRNA and protein expression levels were detected by RT-qPCR and Western blot (WB). Cell apoptosis and cell cycle were detected by flow cytometry. Subcutaneous xenograft model was used to assess in vivo tumor growth. BUBR1 was found to be highly expressed in BC. The high expression of BUBR1 was associated with poor prognosis of BC patients. Upon BUBR1 knockdown using shRNA, the proliferation and metastatic ability of cells were decreased. Moreover, the cells with BUBR1 knockdown underwent cell cycle arrest. And the results showed that BUBR1 loss inhibited the phosphorylation of TAK1/JNK. In vitro and in vivo studies indicated the knockdown of BUBR1 rendered the BC cells more sensitive to cisplatin. In summary, BUBR1 may be a potential therapeutic target for BC and targeting BUBR1 may help overcome cisplatin resistance in BC patients.

Selective targeting of α7 nicotinic acetylcholine receptor by synthetic peptide mimicking loop I of human SLURP-1 provides efficient and prolonged therapy of epidermoid carcinoma in vivo

α7-Type nicotinic acetylcholine receptor (α7-nAChR) promotes the growth and metastasis of solid tumors. Secreted Ly6/uPAR-Related Protein 1 (SLURP-1) is a specific negative modulator of α7-nAChR produced by epithelial cells. Here, we investigated mechanisms of antiproliferative activity of recombinant SLURP-1 in epidermoid carcinoma A431 cells and activity of SLURP-1 and synthetic 21 a.a. peptide mimicking its loop I (Oncotag) in a xenograft mice model of epidermoid carcinoma. SLURP-1 inhibited the mitogenic pathways and transcription factors in A431 cells, and its antiproliferative activity depended on α7-nAChR. Intravenous treatment of mice with SLURP-1 or Oncotag for 10 days suppressed the tumor growth and metastasis and induced sustained changes in gene and microRNA expression in the tumors. Both SLURP-1 and Oncotag demonstrated no acute toxicity. Surprisingly, Oncotag led to a longer suppression of pro-oncogenic signaling and downregulated expression of pro-oncogenic miR-221 and upregulated expression of KLF4 protein responsible for control of cell differentiation. Affinity purification revealed SLURP-1 interactions with both α7-nAChR and EGFR and selective Oncotag interaction with α7-nAChR. Thus, the selective inhibition of α7-nAChRs by drugs based on Oncotag may be a promising strategy for cancer therapy.

Nanosized drug delivery strategies in osteosarcoma chemotherapy

Despite recent developments worldwide in the therapeutic care of osteosarcoma (OS), the ongoing challenges in overcoming limitations and side effects of chemotherapy drugs warrant new strategies to improve overall patient survival. Spurred by rapid progress in biomedicine, nanobiotechnology, and materials chemistry, chemotherapeutic drug delivery in treatment of OS has become possible in recent years. Here, we review recent advances in the design of drug delivery system, especially for chemotherapeutic drugs in OS, and discuss the relative merits in trials along with future therapeutic options. These advances may pave the way for novel therapies requisite for patients with OS.

Alpha7 nicotinic acetylcholine receptor expression in Sorafenib-resistant Hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC), the most prevalent kind of liver cancer, remains one of the world's main causes of death. The alpha7 nicotinic acetylcholine receptor (α7nAchR) has been recognized to be overexpressed in malignancies and chemoresistance. Since little is known about the role of α7nAchR expression in drug-resistant cells, this study was designed to investigate the effect of α7nAchR suppression in combination with Sorafenib (SOR) on SOR-resistant HCC cells. First, SOR-resistant HCC cells were generated. To suppress the expression of α7nAchR, cells were treated with SOR following siRNA transfection. qRT-PCR was used to examine the expression of α7nAchR and apoptotic genes by evaluating the IC50 of SOR and the combination of α7nAchR siRNA and SOR on the survival of resistant cells. Moreover, apoptosis, autophagy, and cell cycle analysis for resistant HCC cells were performed using flow cytometry. Cell migration and colony formation assays were also used for further confirmation. Our results suggest that inhibiting α7nAchR can lead resistant HCC cells to become sensitive. Furthermore, when siRNA and SOR were treated together, HCC-resistant cells showed a considerable reduction in α7nAchR mRNA gene expression. In addition, when α7nAchR was downregulated in combination with SOR, migration and colony formation were inhibited. Apoptosis was triggered by modulating the expression of apoptotic target genes, and cell cycle arrest was observed in the G2-M and subG1 phases. Overexpression of α7nAchR in SOR-resistant HCC cells suggests that it might be a therapeutic target for HCC cell resistance therapy.

α9-Containing Nicotinic Receptors in Cancer

Neuronal nicotinic acetylcholine receptors containing the α9 or the α9 and α10 subunits are expressed in various extra-neuronal tissues. Moreover, most cancer cells and tissues highly express α9-containing receptors, and a number of studies have shown that they are powerful regulators of responses that stimulate cancer processes such as proliferation, inhibition of apoptosis, and metastasis. It has also emerged that their modulation is a promising target for drug development. The aim of this review is to summarize recent data showing the involvement of these receptors in controlling the downstream signaling cascades involved in the promotion of cancer.