Expressions and clinical significance of autophagy-related markers Beclin1, LC3, and EGFR in human cervical squamous cell carcinoma

Potential Therapeutic Action of Autophagy in Gastric Cancer Managements: Novel Treatment Strategies and Pharmacological Interventions

Gastric cancer (GC), second most leading cause of cancer-associated mortality globally, is the cancer of gastrointestinal tract in which malignant cells form in lining of the stomach, resulting in indigestion, pain, and stomach discomfort. Autophagy is an intracellular system in which misfolded, aggregated, and damaged proteins, as well as organelles, are degraded by the lysosomal pathway, and avoiding abnormal accumulation of huge quantities of harmful cellular constituents. However, the exact molecular mechanism of autophagy-mediated GC management has not been clearly elucidated. Here, we emphasized the role of autophagy in the modulation and development of GC transformation in addition to underlying the molecular mechanisms of autophagy-mediated regulation of GC. Accumulating evidences have revealed that targeting autophagy by small molecule activators or inhibitors has become one of the greatest auspicious approaches for GC managements. Particularly, it has been verified that phytochemicals play an important role in treatment as well as prevention of GC. However, use of combination therapies of autophagy modulators in order to overcome the drug resistance through GC treatment will provide novel opportunities to develop promising GC therapeutic approaches. In addition, investigations of the pathophysiological mechanism of GC with potential challenges are urgently needed, as well as limitations of the modulation of autophagy-mediated therapeutic strategies. Therefore, in this review, we would like to deliver an existing standard molecular treatment strategy focusing on the relationship between chemotherapeutic drugs and autophagy, which will help to improve the current treatments of GC patients.

Identification of autophagy-related risk signatures for the prognosis, diagnosis, and targeted therapy in cervical cancer

Background

To rummage autophagy-related prognostic, diagnostic, and therapeutic biomarkers in cervical cancer (CC).

Methods

The RNA-sequence and clinical information were from the TCGA and GTEx databases. We operated Cox regression to determine signatures related to overall survival (OS) and recurrence-free survival (RFS) respectively. The diagnostic and therapeutic effectiveness of prognostic biomarkers were further explored.

Results

We identified nine (VAMP7, MTMR14, ATG4D, KLHL24, TP73, NAMPT, CD46, HGS, ATG4C) and three risk signatures (SERPINA1, HSPB8, SUPT20H) with prognostic values for OS and RFS respectively. Six risk signatures (ATG4C, ATG4D, CD46, TP73, SERPINA1, HSPB8) were selected for qPCR. We screened five prognostic signatures(ATG4C, CD46, HSPB8, MTMR14, NAMPT) with diagnostic function through the GEO database. Correlation between our models and treatment targets certificated the prognostic score provided a reference for precision medicine.

Conclusions

We constructed OS and RFS prognostic models in CC. Autophagy-related risk signatures might serve as diagnostic and therapeutic biomarkers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02073-w.

Facing Cell Autophagy in Gastric Cancer - What Do We Know so Far?

Autophagy is a process by which misfolded proteins and damaged organelles in the lysosomes of tumor cells were degraded reusing decomposed substances and avoiding accumulation of large amounts of harmful substances. Here, the role of autophagy in the development of malignant transformation of gastric tumors, and the underlying mechanisms involved in autophagy formation, and the application of targeted autophagy in the treatment of gastric cancer were summarized.

Effects of Induced Exosomes from Endometrial Cancer Cells on Tumor Activity in the Presence of Aurea helianthus Extract

Endometrial cancer (EC) cells metastasize to various regions, including the ovaries, fallopian tubes, cervix, blood, liver, bone, and brain. Various carcinogens are known to cause EC. Exosomes are released from several types of cells and contain various cellular components. In this study, flow cytometry and quantitative PCR were used to evaluate marker levels, cell migration, cell invasion, and mitochondrial membrane potential, and cellular senescence tests were used to estimate cancer activity. The microRNAs were profiled using next-generation sequencing. Although tocopherol-α and rutin content in Aurea helianthus is high, A. helianthus extract was more useful in modulating tumor activity compared to the two aforementioned substances. Notably, we established that the extract induced bioactive exosomes in EC cells, and profiling of miRNAs in the extract-inducing exosomes (EIE) indicated their potency to be developed as a biological drug. The extract and EIE contributed to the following five biological process categories for EC cells: (1) cell migration and invasion suppression, (2) cellular senescence activation by attenuating mitochondrial membrane potential and enhancing autophagy, (3) reproductive cancer activity attenuation, (4) drug susceptibility activation, and (5) EIE containing miRNAs associated with decreasing inflammation.

The functions of Atg8-family proteins in autophagy and cancer: linked or unrelated?

The Atg8-family proteins are subdivided into two subfamilies: the GABARAP and LC3 subfamilies. These proteins, which are major players of the autophagy pathway, present a conserved glycine in their C-terminus necessary for their association to the autophagosome membrane. This family of proteins present multiple roles from autophagy induction to autophagosome-lysosome fusion and have been described to play a role during cancer progression. Indeed, GABARAPs are described to be downregulated in cancers, and high expression has been linked to a good prognosis. Regarding LC3 s, their expression does not correlate to a particular tumor type or stage. The involvement of Atg8-family proteins during cancer, therefore, remains unclear, and it appears that their anti-tumor role may be associated with their implication in selective protein degradation by autophagy but might also be independent, in some cases, of their conjugation to autophagosomes. In this review, we will then focus on the involvement of GABARAP and LC3 subfamilies during autophagy and cancer and highlight the similarities but also the differences of action of each subfamily member.Abbreviations: AIM: Atg8-interacting motif; AMPK: adenosine monophosphate-associated protein kinase; ATG: autophagy-related; BECN1: beclin 1; BIRC6/BRUCE: baculoviral IAP repeat containing 6; BNIP3L/NIX: BCL2 interacting protein 3 like; GABARAP: GABA type A receptor-associated protein; GABARAPL1/2: GABA type A receptor associated protein like 1/2; GABRA/GABAA: gamma-aminobutyric acid type A receptor subunit; LAP: LC3-associated phagocytosis; LMNB1: lamin B1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; PI4K2A/PI4KIIα: phosphatidylinositol 4-kinase type 2 alpha; PLEKHM1: plecktrin homology and RUN domain containing M1; PtdIns3K-C1: class III phosphatidylinositol 3-kinase complex 1; SQSTM1: sequestosome 1; ULK1: unc51-like autophagy activating kinase 1.

Anti-apoptotic proteins in the autophagic world: an update on functions of XIAP, Survivin, and BRUCE

X-linked inhibitor of apoptosis protein (XIAP), survivin, and BRUCE are members of the inhibitor-of-apoptosis protein (IAP) family known for their inhibitory effects on caspase activity and dysregulation of these molecules has widely been shown to cause embryonic defects and to promote tumorigenesis in human. Besides the anti-apoptotic functions, recent discoveries have revealed that XIAP, survivin, and BRUCE also exhibit regulatory functions for autophagy in cells. As the role of autophagy in human diseases has already been discussed extensively in different reviews; in this review, we will discuss the emerging autophagic role of XIAP, survivin, and BRUCE in cancer cells. We also provide an update on the anti-apoptotic functions and the roles in maintaining DNA integrity of these molecules. Second mitochondria-derived activator of caspases (Smac) is a pro-apoptotic protein and IAPs are the molecular targets of various Smac mimetics currently under clinical trials. Better understanding on the functions of XIAP, survivin, and BRUCE can enable us to predict possible side effects of these drugs and to design a more “patient-specific” clinical trial for Smac mimetics in the future.

Tension induces intervertebral disc degeneration via endoplasmic reticulum stress-mediated autophagy

Background: Intervertebral disc degeneration is a common degenerative disease. The present study aimed to explore the role and mechanism of tension-induced endoplasmic reticulum stress in intervertebral disc degeneration.

Methods: Intervertebral disc degeneration models of SD rat were analyzed for apoptosis, the expression of Poly(ADP-ribose) polymerase (PARP), Caspase-12, Caspase-3, LC3, Beclin-1 and CHOP using immunohistochemistry, qPCR and Western blot analysis. Annulus fibrosus cells of intervertebral disc were isolated, subjected to cyclic deformation stress and analyzed for ROS and apoptosis, lysosome activity and expression of genes. The cells were knockdown with siRNA or treated with endoplasmic reticulum stress inhibitor 4-PBA and assayed for ROS, apoptosis, lysosome activity and gene expression.

Results: Compared with the controls, intervertebral disc degeneration was observed through X-rays examinations and HS staining. Apoptosis and expression of PARP, Caspase-12, Caspase-3, LC3, Beclin-1 and CHOP were significantly increased in the intervertebral disc tissue of the models. In mechanic mimic experiments, the primary annulus fibrosus cells were subjected to 18% cyclic deformation, ROS and apoptosis as well as the activity of lysosome were increased. Similarly, the expression of PARP, Caspase-12, Caspase-3, LC3, Beclin-1 and CHOP was also increased significantly after deformation treatment. On other hand, when the cells were treated with 9 mM 4-PBA and/or CHOP-siRNA4, the apoptosis rate, ROS level, lysosome activity and expression of PARP, Caspase-12, Caspase-3, LC3, Beclin-1 and CHOP were significantly reduced.

Conclusions: Autophagy reaction mediated by endoplasmic reticulum stress plays important rale in tension-induced intervertebral disc degeneration. Intervertebral disc degeneration likely results from interactions between autophagy, apoptosis and reticulum stress, and is ROS-dependent.

Beclin1 overexpression suppresses tumor cell proliferation and survival via an autophagy‑dependent pathway in human synovial sarcoma cells

Beclin1 is an important autophagy‑related prot-ein, which is involved in both autophagy and apoptosis. In recent years, the antitumor effect of Beclin1 has received increased attention. In the present study, we established a stable Beclin1‑overexpressing cell line with SW982 human synovial sarcoma cells. We found that Beclin1 overexpression decreased the cell viability, inhibited proliferation and induced apoptosis in SW982 cells. The expression levels of Bcl‑2 and PCNA were decreased, while the levels of cleaved‑caspase‑3 and cleaved‑PARP were increased. Beclin1 is closely related with autophagy, thus the autophagy‑related markers LC3 and p62 were detected by western blot analysis, and transmission electron microscopy was used to observe autophagosomes. The results showed that the expression level of LC3II was increased and that of p62 was decreased. Moreover, many double membrane‑enclosed autophagosomes were found in cells with Beclin1 overexpression, which indicated that the autophagic activity was enhanced. To explore the effect of autophagy on the viability of SW982 cells, Atg5 was knocked down using siRNA to inhibit the autophagic activity. We found that autophagy contributed to the decrease in cell viability. Knockdown of Atg5 increased the viability and decreased the apoptotic rate of SW982 cells with Beclin1 overexpression. The expression level of Bcl‑2 was increased, while the expression levels of cleaved‑caspase‑3 and cleaved‑PARP were decreased. We also found that the Akt/Bcl‑2/caspase‑9 pathway was involved. The phosphorylation of AKT was positively correlated with cell viability. The cleavage of caspase‑9 was increased by Beclin1 overexpression and decreased by inhibition of autophagy. Altogether, our results suggested that both autophagy and apoptosis contributed to the antitumor effect of Beclin1 in SW982 cells.

Low expression of MAP1LC3B, associated with low Beclin-1, predicts lymph node metastasis and poor prognosis of gastric cancer

Since the roles of autophagy in gastric cancer remain unclear, we aim to investigate the expression of autophagy-related proteins MAP1LC3B and Beclin-1 in human gastric cancer and discuss their clinical significance and correlation with prognosis of patients with gastric cancer. A total of 160 consecutive patients with gastric cancer who had undergone gastrectomy were enrolled in this study. The expressions of MAP1LC3B and Beclin-1 were assessed by immunohistochemistry. The protein expression rates were analyzed with χ ² and Fisher's exact tests. Survival analysis (overall survival (OS) and relapse-free survival (RFS)) was determined using the Kaplan-Meier method and Cox's proportional hazard regression model. Both the expressions of MAP1LC3B and Beclin-1 were lower in gastric cancer tissues than adjacent normal tissues (57 vs. 82 %, p = 0.007; 72 vs. 88 %, p = 0.046, respectively). Relativity analysis indicated MAP1LC3B expression was positively correlated with Beclin-1 expression (r = 0.424, p < 0.001). Both the MAP1LC3B-high-expression patients and Beclin-1-high-expression patients have longer OS time and RFS time than MAP1LC3B-low-expression patients and Beclin-1-low-expression patients (MAP1LC3B: both p < 0.001; Beclin-1: p = 0.014, p = 0.015, respectively). High simultaneous MAP1LC3B and Beclin-1 expressions were associated with longer OS and RFS compared with low simultaneous MAP1LC3B and Beclin-1 expressions (56.77 vs. 24.42 months, p < 0.001; 53.56 vs. 22.33 months, p < 0.001, respectively). Multivariate survival analysis showed both MAP1LC3B and Beclin-1 were independent prognostic factors for OS time (p = 0.016, p = 0.041, respectively). However, MAP1LC3B (p = 0.022) was an independent prognostic factor for RFS. Moreover, low expressions of MAP1LC3B and Beclin-1 were significantly associated with lymph node metastasis (p = 0.007, p = 0.030, respectively). The loss of MAP1LC3B, correlated with loss of Beclin-1, was observed in gastric cancer and correlated with poor prognosis and lymph node metastasis of gastric cancer patients.