The impact of DAPK1 and mTORC1 signaling association on autophagy in cancer

BACKGROUND

The autophagy pathway is used by eukaryotic cells to maintain metabolic homeostasis. Autophagy has two functions in cancerous cells which could inhibit tumorigenesis or lead to cancer progression by increasing cell survival and proliferation.

METHODS AND RESULTS

In this review article, Web of Science, PubMed, Scopus,  and Google Scholar were searched and summarized published studies to explore the relationship between DAPK1 and mTORC1 signaling association on autophagy in cancer. Autophagy is managed through various proteins including the mTOR, which is two separated structural and functional complexes known as mTORC1 and mTORC2. MTORC1 is an important component of the regulatory pathway affecting numerous cellular functions including proliferation, migration, invasion, and survival. This protein plays a key role in human cancers. The activity level of mTORC1 is regulated by the death-associated protein kinases (DAPks) family, especially DAPK1. In many cancers, DAPK1 acts as a tumor suppressor which can be attributed to its ability to suppress cellular transformation and to inhibit metastasis.

CONCLUSIONS

A deep investigation not only will reveal more about the function of DAPK1 but also might provide insights into novel therapies aimed to modulate the autophagy pathway in cancer and to achieve better cancer therapy.

Regulation of autophagy by microRNAs in human breast cancer

Breast cancer is the most common solid cancer that affects female population globally. MicroRNAs (miRNAs) are short non-coding RNAs that can regulate post-transcriptional modification of multiple downstream genes. Autophagy is a conserved cellular catabolic activity that aims to provide nutrients and degrade un-usable macromolecules in mammalian cells. A number of in vitro, in vivo and clinical studies have reported that some miRNAs could modulate autophagy activity in human breast cancer cells, and these would influence human breast cancer progression and treatment response. Therefore, this review was aimed to discuss the roles of autophagy-regulating miRNAs in influencing breast cancer development and treatment response. The review would first introduce autophagy types and process, followed by the discussion of the roles of different miRNAs in modulating autophagy in human breast cancer, and to explore how would this miRNA-autophagy regulatory process affect the disease progression or treatment response. Lastly, the potential applications and challenges of utilizing autophagy-regulating miRNAs as breast cancer biomarkers and novel therapeutic agents would be discussed.

Angiogenesis regulation by microRNAs and long non-coding RNAs in human breast cancer

MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are capable of regulating gene expression post-transcriptionally. Since the past decade, a number of in vitro, in vivo, and clinical studies reported the roles of these non-coding RNAs (ncRNAs) in regulating angiogenesis, an important cancer hallmark that is associated with metastases and poor prognosis. The specific roles of various miRNAs and lncRNAs in regulating angiogenesis in breast cancer, with particular focus on the downstream targets and signalling pathways regulated by these ncRNAs will be discussed in this review. In light of the recent trend in exploiting ncRNAs as cancer therapeutics, the potential use of miRNAs and lncRNAs as biomarkers and novel therapeutic agent against angiogenesis was also discussed.

Dysregulation of miR-638 in the progression of cancers

MicroRNA (miRNA) is a form of short, single-stranded and non-coding RNA that is important in regulating the post-transcriptional modification of multiple downstream targets. Many miRNAs have been reported to involve in controlling the progression of human diseases, and one of them is miR-638, which play essential roles in regulating the development of human cancer. By targeting the 3'-ends of its targets, miR-638 can regulate cellular processes including proliferation, invasion, metastases, angiogenesis, apoptosis and inflammation. This review was aimed to summarize current findings on the roles of miR-638 in different human cancers based on the results from various in vitro, in vivo and clinical studies. The biogenesis process and tissue expression, followed by the roles of miR-638 in regulating the development of various human cancers by targeting different downstream targets were covered in this review. The potential applications and challenges of employing miR-638 as cancer biomarker and therapeutic agent were also discussed.