Dying cells interact with living cells and release molecules that can signal to immune system. Based on the morphology of the dying cells, there are three types of cell death, which are apoptotic cell death (Type I), autophagic cell death (Type II) and necrotic cell death (Type III). The immune response is different according to the pathway of cell death as apoptosis or necrosis regulates immune response via caspase activation or cytokine secretion, respectively. Here, we discuss the different modes of cell death and the nature of the immune response elicited by the released molecules from the cell death.
Apoptosis ; Autophagy ; Cell Death ; Immune System ; Necrosis

Chemotherapy has long been considered as one of useful strategies for cancer treatment. It is primarily based on the apoptosis that can selectively kill cancer cells. However, cancer cells can progressively develop an acquired resistance to apoptotic cell death, rendering refractory to chemo- and radiotherapies. Although the mechanism by which cells attained resistance to drug remains to be clarified, it might be caused by either pumping out of them or interfering with apoptotic signal cascades in response to cancer drugs. In case that cancer cells are defective in some part of apoptotic machinery by repeated exposure to anticancer drugs, alternative cell death mechanistically distinct from apoptosis could be adopted to remove cancer cells refractory to apoptosis-inducing agents. This review will mainly deal with harnessing of necrotic cell death, specifically, programmed necrosis and practical uses. Here, we begin with various defects of apoptotic death machinery in cancer cells, and then provide new perspective on programmed necrosis as an alternative anticancer approach.
Apoptosis ; Autophagy ; Cell Death ; Drug Therapy ; Necrosis* ; Radiotherapy

Cell death is a major physiological or pathological phenomenon in life activities. The classic forms of cell death include apoptosis, necrosis, and autophagy. Recently, a novel type of cell death has been observed and termed as methuosis, in which excessive stimuli can induce cytoplasmic uptake and accumulation of small bubbles that gradually merge into giant vacuoles, eventually leading to decreased cellular metabolic activity, cell membrane rupture and cell death. In this article, we describe the nomenclature, morphological characteristics and underlying mechanisms of methuosis, compare methuosis with autophagy, oncosis and paraptosis, and review the related researches.
Apoptosis ; Autophagy ; Cell Death ; Cytoplasm ; Humans ; Necrosis ; Vacuoles

There is mounting evidence that autophagy is involved in diverse physiological and pathological processes that have immense relevance in human development, diseases and aging. Immunity and inflammation are not exceptions. Here, the role of autophagy in the control of immune processes particularly that related to cell death and inflammation is discussed.
Aging ; Apoptosis ; Autophagy ; Cell Death ; Human Development ; Inflammation ; Necrosis ; Pathologic Processes

There is mounting evidence that autophagy is involved in diverse physiological and pathological processes that have immense relevance in human development, diseases and aging. Immunity and inflammation are not exceptions. Here, the role of autophagy in the control of immune processes particularly that related to cell death and inflammation is discussed.
Aging ; Apoptosis ; Autophagy ; Cell Death ; Human Development ; Inflammation ; Necrosis ; Pathologic Processes

Animals ; Apoptosis ; Cell Death ; Humans ; Necrosis

Quercetin is a natural flavonoid phytochemical that is extracted from various plants. Having an advantages due to its varied biological properties, such as anti-inflammatory, anti-viral, anti-oxidant, and anti-cancer effects, quercetin is used to treat many diseases. Recently, it has been reported that autophagy inhibition may play a key role in anti-cancer therapy. Therefore, in this study, we investigated the molecular mechanisms and anti-cancer effects of quercetin in human osteosarcoma cells via autophagy inhibition. We ascertained that quercetin inhibited cell proliferation and induced cell death, these process is demonstrated that apoptosis via the mitochondrial pathway and the caspase cascade. Quercetin also induced autophagy which was inhibited by 3-MA, autophagy inhibitor and the blockade of autophagy promoted the quercetin-induced apoptosis, confirming that autophagy is a pro-survival process. Thus, these findings demonstrate that quercetin is an effective anti-cancer agent, and the combination of quercetin and an autophagy inhibitor should enhance the effect of anti-cancer therapy.
Apoptosis* ; Autophagy* ; Cell Death ; Cell Proliferation ; Humans ; Osteosarcoma* ; Quercetin*

Autophagy, a cellular process of "self-eating" by which intracellular components are degraded within the lysosome, is an evolutionarily conserved response to various stresses. Autophagy is associated with numerous patho-physiological conditions, and dysregulation of autophagy contributes to the pathogenesis of a variety of human diseases including cancer. Depending on context, activation of autophagy may promote either cell survival or death, two major events that determine pathological process of many illnesses. Importantly, the activity of autophagy is often associated with apoptosis, another critical cellular process determining cellular fate. A better understanding of biology of autophagy and its implication in human health and disorder, as well as the relationship between autophagy and apoptosis, has the potential of facilitating the development of autophagy-based therapeutic interventions for human diseases such as cancer.
Apoptosis ; Autophagy ; Cell Death ; Cell Survival ; Humans ; Neoplasms ; pathology

The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor family of cytokines. TRAIL selectively induces apoptotic cell death in various tumors and cancer cells, but it has little or no toxicity in normal cells. Agonism of TRAIL receptors has been considered to be a valuable cancer-therapeutic strategy. However, more than 85% of primary tumors are resistant to TRAIL, emphasizing the importance of investigating how to overcome TRAIL resistance. In this report, we have found that nemadipine-A, a cell-permeable L-type calcium channel inhibitor, sensitizes TRAIL-resistant cancer cells to this ligand. Combination treatments using TRAIL with nemadipine-A synergistically induced both the caspase cascade and apoptotic cell death, which were blocked by a pan caspase inhibitor (zVAD) but not by autophagy or a necrosis inhibitor. We further found that nemadipine-A, either alone or in combination with TRAIL, notably reduced the expression of survivin, an inhibitor of the apoptosis protein (IAP) family of proteins. Depletion of survivin by small RNA interference (siRNA) resulted in increased cell death and caspase activation by TRAIL treatment. These results suggest that nemadipine-A potentiates TRAIL-induced apoptosis by down-regulation of survivin expression in TRAIL resistant cells. Thus, combination of TRAIL with nemadipine-A may serve a new therapeutic scheme for the treatment of TRAIL resistant cancer cells, suggesting that a detailed study of this combination would be useful.
Apoptosis* ; Autophagy ; Calcium Channels, L-Type ; Cell Death ; Cytokines ; Down-Regulation* ; Felodipine ; Humans ; Necrosis ; Receptors, TNF-Related Apoptosis-Inducing Ligand ; RNA Interference ; Tumor Necrosis Factor-alpha

Ferroptosis is defined as an iron-dependent, non-apoptotic cell death pathway, with specific morphological phenotypes and biochemical changes. There is a growing realization that ferroptosis has significant implications for several neurodegenerative diseases. Even though ferroptosis is different from other forms of programmed death such as apoptosis and autophagic death, they involve a number of common protein molecules. This review focuses on current research on ferroptosis and summarizes the cross-talk among ferroptosis, apoptosis, and autophagy that are implicated in neurodegenerative diseases. We hope that this information provides new ideas for understanding the mechanisms and searching for potential therapeutic approaches and prevention of neurodegenerative diseases.
Apoptosis ; Autophagy ; Cell Death ; Ferroptosis ; Humans ; Neurodegenerative Diseases