The Role of Phosphatidylinositol 3-Kinase Catalytic Subunit Type 3 in the Pathogenesis of Human Cancer

Recent advances of vacuolar protein-sorting 34 inhibitors targeting autophagy

Autophagy is a ubiquitous pathological/physiological antioxidant cellular reaction in eukaryotic cells. Vacuolar protein sorting 34 (Vps34 or PIK3C3), which plays a crucial role in autophagy, has received much attention. As the only Class III phosphatidylinositol-3 kinase in mammals, Vps34 participates in vesicular transport, nutrient signaling and autophagy. Dysfunctionality of Vps34 induces carcinogenesis, and abnormal autophagy mediated by dysfunction of Vps34 is closely related to the pathological progression of various human diseases, which makes Vps34 a novel target for tumor immunotherapy. In this review, we summarize the molecular mechanisms underlying macroautophagy, and further discuss the structure-activity relationship of Vps34 inhibitors that have been reported in the past decade as well as their potential roles in anticancer immunotherapy to better understand the antitumor mechanism underlying the effects of these inhibitors.

Autoimmune Thyroid Disease and Differentiated Thyroid Carcinoma: A Review of the Mechanisms That Explain an Intriguing and Exciting Relationship

Autoimmune thyroid disease is a complex and highly frequent disease, where a wide variety of genetic, epigenetic and environmental factors (among others) come together and interact, and is characterized by the presence of two clinical outcomes: hypothyroidism (in Hashimoto's thyroiditis) and hyperthyroidism (in Graves-Basedow disease). For its part, differentiated thyroid carcinoma (mainly papillary carcinoma) is the most common type of cancer affecting the thyroid (and one of the most prevalent worldwide). An important co-occurrence between autoimmune thyroid disease and differentiated thyroid carcinoma has been documented. In this article, studies that have evaluated possible associations and relationships between autoimmune thyroid disease and differentiated thyroid cancer are systematically described and summarized. To date, the underlying mechanism that explains this association is inflammation; however, the characteristics and designs of the studies evaluated do not yet allow a causal relationship between the two entities to be established. These aspects have made it difficult to establish "causality" in the continuum of the pathogenesis between both conditions.

Tight Junction Protein 1 Suppresses Kidney Renal Clear Cell Carcinoma Cells Proliferation by Inducing Autophagy

TJP1, an adaptor protein of the adhesive barrier, has been found to exhibit distinct oncogenic or tumor suppressor functions in a cell-type dependent manner. However, the role of TJP1 in kidney renal clear cell carcinoma (KIRC) remains to be explored. The results showed a marked down-regulation of TJP1 in KIRC tissues compared to normal tissues. Low expression of TJP1 was significantly associated with high grade and poor prognosis in KIRC. Autophagosome aggregation and LC3 II conversion demonstrated that TJP1 may induce autophagy signaling in 786-O and OS-RC-2 cells. Knockdown of TJP1 led to a decrease in the expression of autophagy-related genes, such as BECN1, ATG3, and ATG7. Consistently, TJP1 expression showed a significant positive correlation with these autophagy-related genes in KIRC patients. Furthermore, the overall survival analysis of KIRC patients based on the expression of autophagy-related genes revealed that most of these genes were associated with a good prognosis. TJP1 overexpression significantly suppressed cell proliferation and tumor growth in 786-O cells, whereas the addition of an autophagy inhibitor diminished its inhibitory function. Taken together, these results suggest that TJP1 serves as a favorable prognostic marker and induces autophagy to suppress cell proliferation and tumor growth in KIRC.

Relating aging and autophagy: a new perspective towards the welfare of human health

The most common factor that contributes to aging is the loss of proteostasis, resulting in an excess amount of non-functional/damaged proteins. These proteins lead to various age-associated phenotypes such as cellular senescence and dysfunction in the nutrient-sensing pathways. Despite the various factors that can contribute to aging, it is still a process that can be changed. According to recent advances in the field of biology, the ability to alter the pathways that are involved in aging can improve the lifespan of a person. Autophagy is a process that helps in preserving survival during stressful situations, such as starvation. It is a common component of various anti-aging interventions, including those that target the insulin/IGF-1 and rapamycin signaling pathways. It has been shown that altered autophagy is a common feature of old age and its impaired regulation could have significant effects on the aging process. This review aims to look into the role of autophagy in aging and how it can be used to improve one's health.

Targeting VPS34 in autophagy: An update on pharmacological small-molecule compounds

VPS34 is well-known to be the unique member of the class III phosphoinositide 3-kinase (PI3K) family, forming VPS34 complex 1 and complex 2, which are involved in several key physiological processes. Of note, VPS34 complex 1 is an important node of autophagosome generation, which controls T cell metabolism and maintains cellular homeostasis through the autophagic pathway. And, VPS34 complex 2 is involved in endocytosis as well as vesicular transport, and is closely related to neurotransmission, antigen presentation and brain development. Due to the two important biological functions of VPS34, its dysregulation can lead to the development of cardiovascular disease, cancer, neurological disorders, and many types of human diseases by altering normal human physiology. Thus, in this review, we not only summarize the molecular structure and function of VPS34, but demonstrate the relationships between VPS34 and human diseases. Moreover, we further discuss the current small molecule inhibitors targeting VPS34 based upon the structure and function of VPS34, which may provide an insight into the future targeted drug development.

PI3K/AKT/mTOR-Targeted Therapy for Breast Cancer

Phosphatidylinositol 3-kinase (PI3K), protein kinase B (PKB/AKT) and mechanistic target of rapamycin (mTOR) (PAM) pathways play important roles in breast tumorigenesis and confer worse prognosis in breast cancer patients. The inhibitors targeting three key nodes of these pathways, PI3K, AKT and mTOR, are continuously developed. For breast cancer patients to truly benefit from PAM pathway inhibitors, it is necessary to clarify the frequency and mechanism of abnormal alterations in the PAM pathway in different breast cancer subtypes, and further explore reliable biomarkers to identify the appropriate population for precision therapy. Some PI3K and mTOR inhibitors have been approved by regulatory authorities for the treatment of specific breast cancer patient populations, and many new-generation PI3K/mTOR inhibitors and AKT isoform inhibitors have also been shown to have good prospects for cancer therapy. This review summarizes the changes in the PAM signaling pathway in different subtypes of breast cancer, and the latest research progress about the biomarkers and clinical application of PAM-targeted inhibitors.