Aberrant expression of Beclin-1 and LC3 correlates with poor prognosis of human hypopharyngeal squamous cell carcinoma

The dual role of autophagy in HPV-positive head and neck squamous cell carcinoma: a systematic review

PURPOSE

Human papilloma virus (HPV)-positive head and neck squamous cell carcinoma (HNSCC) displays distinct epidemiological, clinical, and molecular characteristics compared to the negative counterpart. Alterations in autophagy play an important role in cancer, and emerging evidence indicates an interplay of autophagy in HNSCC carcinogenesis and tumor promotion. However, the influence of HPV infection on autophagy in HNSCC has received less attention and has not been previously reviewed. Therefore, we here aimed to systematically review the role of autophagy explicitly in HPV+ HNSCC.

METHODS

Studies accessible in PubMed, Embase, Scopus, and Web of Science investigating HNSCC, highlighting the molecular biological differences between HPV- and HPV+ HNSCC and its influences on autophagy in HNSCC were analyzed according to the PRISMA statement. A total of 10 articles were identified, included, and summarized.

RESULTS

The HPV16 E7 oncoprotein was reported to be involved in the degradation of AMBRA1 and STING, and to enhance chemotherapy-induced cell death via lethal mitophagy in HNSCC cells. Autophagy-associated gene signatures correlated with HPV-subtype and overall survival. Additionally, immunohistochemical (IHC) analyses indicate that high LC3B expression correlates with poor overall survival in oropharyngeal HNSCC patients.

CONCLUSION

HPV may dampen general bulk autophagic flux via degradation of AMBRA1 but may promote selective autophagic degradation of STING and mitochondria. Interpretations of correlations between autophagy-associated gene expressions or IHC analyses of autophagy-related (ATG) proteins in paraffin embedded tissue with clinicopathological features without biological validation need to be taken with caution.

CPT1A mediates chemoresistance in human hypopharyngeal squamous cell carcinoma via ATG16L1-dependent cellular autophagy

Hypopharyngeal squamous cell carcinoma (HSCC) is a highly aggressive malignancy that constitutes approximately 95% of all hypopharyngeal carcinomas, and it carries a poor prognosis. The primary factor influencing the efficacy of anti-cancer drugs for this type of carcinoma is chemoresistance. Carnitine palmitoyltransferase 1A (CPT1A) has been associated with tumor progression in various cancers, including breast, gastric, lung, and prostate cancer. The inhibition or depletion of CPT1A can lead to apoptosis, curbing cancer cell proliferation and chemoresistance. However, the role of CPT1A in HSCC is not yet fully understood. In this study, we discovered that CPT1A is highly expressed in HSCC and is associated with an advanced T-stage and a poor 5-year survival rate among patients. Furthermore, the overexpression of CPT1A contributes to HSCC chemoresistance. Mechanistically, CPT1A can interact with the autophagy-related protein ATG16L1 and stimulate the succinylation of ATG16L1, which in turn drives autophagosome formation and autophagy. We also found that treatment with 3-methyladenine (3-MA) can reduce cisplatin resistance in HSCC cells that overexpress CPT1A. Our findings also showed that a CPT1A inhibitor significantly enhances cisplatin sensitivity both in vitro and in vivo. This study is the first to suggest that CPT1A has a regulatory role in autophagy and is linked to poor prognosis in HSCC patients. It presents novel insights into the roles of CPT1A in tumorigenesis and proposes that CPT1A could be a potential therapeutic target for HSCC treatment.

Role of PPARG in Chemosensitivity-Regulating Network for Hypopharyngeal Squamous Cell Carcinoma

PPARG has been reported to promote chemosensitivity in hypopharyngeal squamous cell carcinoma (HSCC). However, few studies tested its significance in the texture of a complex molecular network regulating chemosensitivity in HSCC. Here, we first employed RNA expression data analysis and literature data mining to uncover candidate genes related to HSCC chemosensitivity. Then, we constructed the molecular network regulating chemosensitivity in HSCC. After that, we employed degree centrality (DC) and weighted centrality (WC) to test the significance of PPARG within the regulating network. Pathway enrichment was done to study the cofunctions of PPARG and the rest of the genes within the network. The findings of our study contribute to the construction of a comprehensive network that regulates HSCC chemosensitivity, consisting of 57 genes, including PPARG. Notably, within this network, PPARG demonstrates a ranking of #5 and #13 based on DC and WC, respectively. Moreover, PPARG is connected to 29 out of the 57 genes and plays roles in multiple functional groups. These top related genes include AKT1, TP53, PTEN, MAPK1, NOTCH1, BECN1, PTGS2, SPP1, and RAC1. PPARG gets enriched in several key functional groups that have been implicated in the regulation of chemosensitivity, including those associated with the response to nutrients, vitamins, and peptides, the cellular response to chemical stress, and the regulation of hormone secretion and growth. Our results emphasize the involvement of PPARG and its interconnectedness with other genes in the regulation of HSCC chemosensitivity.

LSD1 silencing inhibits the proliferation, migration, invasion, and epithelial-to-mesenchymal transition of hypopharyngeal cancer cells by inducing autophagy and pyroptosis

Hypopharyngeal cancer is a subtype of the head and neck malignancies. We aimed to explore the role of lysine-specific demethylase 1 (LSD1/KDM1A) in the progression of hypopharyngeal cancer and to identify the potential mechanisms. First, LSD1 expression in head and neck squamous cell carcinoma (HNSCC) tissues and the correlation between LSD1 and the stage of HNSC were analyzed by the University of ALabama at Birmingham CANcer data analysis Portal (UALCAN). Following LSD1 silencing, proliferation of pharyngeal cancer cell line FaDu cells was evaluated by cell counting kit-8 and colony formation assays. Wounding healing and transwell assays were used to measure the capacities of migration and invasion. In addition, expression of proteins related to epithelial-to-mesenchymal transition (EMT), autophagy, and pyroptosis was tested by Western blot analysis or immunofluorescence. After treatment with autophagy inhibitor 3-methyladenine (3-MA) or NLR family pyrin domain containing 3 (NLRP3) inhibitor MCC950, the malignant biological properties were measured again. High LSD1 expression was observed in HNSC tissues, which was correlated with stage. LSD1 knockdown significantly suppressed the proliferation, migration, invasion, and EMT of hypopharyngeal cancer cells. Moreover, autophagy and pyroptosis were induced by LSD1 depletion, observed by the enhanced fluorescence intensity of LC3, gasdermin-D (GSDMD)-N, and apoptosis-associated speck-like protein containing a CARD (ASC), accompanied by upregulated expression of LC3II/LC3I, Beclin-1, NLRP3, cleaved-caspase 1, ASC, interleukin (IL)-1β, and IL-18 and downregulated expression of p62. Importantly, 3-MA or MCC950 addition obviously reversed the inhibitory effects of LSD1 silencing on the proliferation, migration, invasion, and EMT of hypopharyngeal cancer cells. To sum up, LSD1 silencing could restrain the progression of hypopharyngeal cancer cells by inducing autophagy and pyroptosis.

The potential effect of Schisandrin-B combination with panitumumab in wild-type and mutant colorectal cancer cell lines: Role of apoptosis and autophagy

Panitumumab is an approved monoclonal antibody for the treatment of colorectal cancer (CRC); however, mutations in EGFR signaling pathway resulted in poor response. Schisandrin-B (Sch-B) is a phytochemical that was suggested to protect against inflammation, oxidative stress, and cell proliferation. The present study aimed to investigate the potential effect of Sch-B on panitumumab-induced cytotoxicity in wild-type Caco-2, and mutant HCT-116 and HT-29 CRC cell lines, and the possible underlying mechanisms. CRC cell lines were treated with panitumumab, Sch-B, and their combination. The cytotoxic effect of drugs was determined by MTT assay. The apoptotic potential was assessed in-vitro by DNA fragmentation and caspase-3 activity. Additionally, autophagy was investigated via microscopic detection of autophagosomes and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) measurement of Beclin-1, Rubicon, LC3-II, and Bcl-2 expression. The drug pair enhanced panitumumab cytotoxicity in all CRC cell lines where IC50 of panitumumab was decreased in Caco-2 cell line. Apoptosis was induced through caspase-3 activation, DNA fragmentation, and Bcl-2 downregulation. Caco-2 cell line treated with panitumumab showed stained acidic vesicular organelles, contrariwise, all cell lines treated with Sch-B or the drug pair displayed green fluorescence indicating the lack of autophagosomes. qRT-PCR revealed the downregulation of LC3-II in all CRC cell lines, Rubicon in mutant cell lines, and Beclin-1 in HT-29 cell line only. Sch-B at 6.5 µM promoted panitumumab-induced apoptotic cell death, in-vitro, via caspase-3 activation and Bcl-2 downregulation, rather than autophagic cell death. This novel combination therapy against CRC, allows the reduction of panitumumab dose to guard against its adverse effects.

Evaluation of the expression of LC3-II and BECLIN1 genes of autophagy pathway in patients with hematological malignancies

Background

Autophagy is a pathway for the degradation of cytoplasmic components, which plays an essential role in various cellular and physiological processes, including cell renewal and survival, and immune responses. While recent studies have shown that they can play a role in cancer treatment, the precise mechanisms of autophagy in leukemogenesis are not fully understood. We have assessed the expression levels of LC3 and BECLIN1 as two crucial autophagy mediators in patients with leukemia.

Methods

This cross-sectional study was performed on bone marrow or peripheral blood samples of 61 leukemia patients (24 AML, 20 ALL, and 17 CML) and compared to 18 healthy controls. Real-time PCR was used to quantitate gene expression. SPSS statistics 16.0 and Graph Pad Prism 8.4.2 software were applied for statistical analysis.

Results

While BECLIN1 expression was significantly lower in AML, ALL, and CML patients as compared to the control group (p < 0.05), LC3 showed significantly different expression only in the AML patients (P= 0.03). There was no significant correlation between the expression levels of BECLIN1 with LC3 (p> 0.05). Whilst the AML LC3high group had a significantly lower lymphocyte count (P= 0.023), the AML BECLIN1low group had a significantly higher MPV levels (P= 0.044). Furthermore, ALL LC3high group indicated a significantly lower HCT count (P= 0.017).

Conclusion

Significant changes in the expression levels of BECLINI and LC3 in hematologic malignancies may indicate a possible role for autophagy in their pathogenesis. However, further studies are warranted to confirm these findings.

Investigation of chemoresistance to first-line chemotherapy and its possible association with autophagy in high-risk neuroblastoma

High-risk neuroblastoma (NB) is sensitive to chemotherapy but susceptible to chemoresistance. In this study, we aimed to analyze the incidence of chemoresistance in high-risk NB patients and to explore the role of autophagy in NB chemoresistance. We retrospectively analyzed the incidence of changing the chemotherapy regimen due to disease stabilization or disease progression during induction chemotherapy in high-risk NB patients, which was expressed as the chemoresistance rate. The autophagy levels were probed in tumor cells exposed to first-line chemotherapy agents. The sensitivity of tumor cells to chemotherapy agents and apoptosis rate were observed after inhibiting autophagy by transfection of shRNA or chloroquine (CQ). This study included 247 patients with high-risk NB. The chemoresistance rates of patients treated with cyclophosphamide + adriamycin + vincristine (CAV) alternating with etoposide + cisplatin (EP) (Group 1) and CAV alternating with etoposide + ifosfamide + cisplatin (VIP) (Group 2) was 61.5% and 39.9% (P = 0.0009), respectively. Group 2 had better survival rates than group 1. After exposure to cisplatin, cyclophosphamide, and etoposide, the autophagy-related proteins LC3-I, LC3-II, and Beclin-1 were upregulated, and the incidence of autophagy vesicle formation and the expression of P62 were increased. Chemotherapeutic agents combined with CQ significantly increased the chemotherapeutic sensitivity of tumor cells and increased the cell apoptosis. The downregulated expression of Beclin-1 increased the sensitivity of tumor cells to chemotherapeutics. Our results suggest that increasing the chemotherapy intensity can overcome resistance to NB. Inhibition of autophagy is beneficial to increase the sensitivity of NB to chemotherapy agents.

Glycyrrhizic acid ameliorates submandibular gland oxidative stress, autophagy and vascular dysfunction in rat model of type 1 diabetes

The burden of diabetes mellitus (DM) and associated complications is increasing worldwide, affecting many organ functionalities including submandibular glands (SMG). The present study aims to investigate the potential ameliorative effect of glycyrrhizic acid (GA) on diabetes-induced SMG damage. Experimental evaluation of GA treatment was conducted on a rat model of type I diabetes. Animals were assigned to three groups; control, diabetic and GA treated diabetic groups. After 8 weeks, the SMG was processed for assessment of oxidative stress markers, autophagy related proteins; LC3, Beclin-1 and P62, vascular regulator ET-1, aquaporins (AQPs 1.4 and 5), SIRT1 protein expressions in addition to LC3 and AQP5 mRNA expressions. Also, parenchymal structures of the SMG were examined. GA alleviated the diabetes-induced SMG damage via restoring the SMG levels of oxidative stress markers and ET-1 almost near to the normal levels most probably via regulation of SIRT1, AQPs and accordingly LC-3, P62 and Beclin-1levels. GA could be a promising candidate for the treatment of diabetes-induced SMG damage via regulating oxidative stress, autophagy and angiogenesis.

Combined Evaluation of MAP1LC3B and SQSTM1 for Biological and Clinical Significance in Ductal Carcinoma of Breast Cancer

Breast cancer is the leading cause of cancer death in women worldwide. The microtubule-associated protein light chain 3B (MAP1LC3B) and adaptor sequestosome 1 (SQSTM1) are two major markers for autophagy. Increased protein levels of MAP1LC3B and SQSTM1 are considered to be causes of autophagy inhibition or activation in various types of cancers. However, the roles of MAP1LC3B and SQSTM1 in breast cancer are still not clear. Using a tissue microarray from 274 breast invasive ductal carcinoma (IDC) patients, we found that tumor tissues showed higher protein levels of MAP1LC3B and cytoplasmic SQSTM1 in comparison to those in adjacent normal tissues. Moreover, high levels of MAP1LC3B were associated with better survival, including disease-specific survival and disease-free survival (DFS) in IDC patients. Furthermore, high co-expression of MAP1LC3B and SQSTM1 was significantly associated with better DFS in IDC patients. Astonishingly, the autophagy inhibitor accumulated the protein levels of MAP1LC3B/SQSTM1 and enhanced the cytotoxic effects of cisplatin and paclitaxel in MCF7 and BT474 breast cancer cell lines, implying that autophagy inhibition might result in poor prognosis and chemosensitivity in IDC. Taken together, high co-expression of MAP1LC3B and SQSTM1 might serve as a potential diagnostic and prognostic biomarker for IDC patients.

LACTB and LC3 could serve as potential biomarkers of gastric cancer to neoadjuvant chemotherapy with oxaliplatin plus S-1

The present study investigated and evaluated the correlation between the expression of LACTB and LC3 and the clinical outcomes of patients with advanced gastric cancer treated with oxaliplatin plus S-1 neoadjuvant chemotherapy (NACT). A total of 51 patients with advanced gastric cancer underwent NACT treatment between June 2015 and June 2017. Pathomorphological changes in gastric cancer were analyzed by H&E staining. The expression level and subcellular localization of LACTB and LC3 in paraffin-embedded biopsies were detected by immunohistochemistry and immunofluorescence. The mRNA and protein expression of LACTB were investigated by reverse transcription quantitative polymerase chain reaction and Western blotting, respectively. Statistical analysis was performed to determine the association between the expression of LACTB and LC3 and clinical chemotherapy efficacy of NACT for gastric cancer. Among the 51 patients, 3 (5.88%), 27 (52.94%), 13 (25.49%) and 8 (15.69%) displayed complete remission, partial remission, stable disease and progressive disease, respectively. The rate of decreased LACTB expression was 68.6%, while the rate of increased LC3 expression was 60.8%. Furthermore, there was a significant negative correlation between the expression of LACTB and that of LC3 following NACT (P<0.001). High expression of LC3 (P<0.01) and low expression of LACTB (P<0.01) were associated with a poor response of patients with advanced gastric cancer to NACT. In conclusion, the expression of LACTB and LC3 may serve as a promising novel biomarker for determining the prognosis of patients with advanced gastric cancer receiving NACT, while its potential clinical significance requires further elucidation.

Hypoxia enhances basal autophagy of epithelial-derived ameloblastoma cells

Ameloblastoma is a locally aggressive odontogenic tumor. Etiopathogenesis and locally aggressive growth properties of ameloblastoma can be attributed to a hypoxic microenvironment conducive to tumor cell survival. Epithelial-derived follicular ameloblastoma cells (EP-AMCs) display enhanced basal autophagy, but the interplay of hypoxia and autophagy in EP-AMCs survival and ameloblastoma recurrence is unclear. We evaluated differential expression of autophagic markers in primary and recurrent ameloblastomas and hypothesized that hypoxia-induced autophagy supports EP-AMC survival. Primary and recurrent ameloblastomas were comparatively assessed for expression levels of pan-cytokeratin, Vimentin, and autophagic markers SQSTM1/p62, LC3, and pS6. EP-AMCs compared with human odontoma-derived cells (HODCs) were subjected to severe hypoxia to determine the interplay of hypoxia and autophagic process in posthypoxia survival. Pan-cytokeratin and SQSTM1/p62 were expressed by both primary and recurrent ameloblastoma epithelial cells while the ameloblastoma connective tissues displayed weak reactivity to vimentin. Under hypoxia, EP-AMC expression levels of hypoxia-inducible factor (HIF)-1α, p62, and LC3 were increased while pS6 was decreased posthypoxia. The combined decrease in pS6 and enhanced LC3 in EP-AMCs under hypoxia indicate that EP-AMCs re-establish basal autophagy under hypoxia. Taken together, these suggest a possible role of LC3-associated phagocytosis (LAP) in ameloblastoma cell survival.

Chloroform fraction of Chaetomorpha brachygona, a marine green alga from Indian Sundarbans inducing autophagy in cervical cancer cells in vitro

Sundarbans Mangrove Ecosystem (SME) is a rich repository of bioactive natural compounds, with immense nutraceutical and therapeutic potential. Till date, the algal population of SME was not explored fully for their anticancer activities. Our aim is to explore the potential of these algal phytochemicals against the proliferation of cervical cancer cells (in vitro) and identify the mode of cell death induced in them. In the present work, the chloroform fraction of marine green alga, Chaetomorpha brachygona was used on SiHa cell line. The algal phytochemicals were identified by GCMS, LCMS and column chromatography and some of the identified compounds, known for significant anticancer activities, have shown strong Bcl-2 binding capacity, as analyzed through molecular docking study. The extract showed cytostatic and cytotoxic activity on SiHa cells. Absence of fragmented DNA, and presence of increased number of acidic vacuoles in the treated cells indicate nonapoptotic cell death. The mode of cell death was likely to be autophagic, as indicated by the enhanced expression of Beclin 1 and LC3BII (considered as autophagic markers) observed by Western blotting. The study indicates that, C. brachygona can successfully inhibit the proliferation of cervical cancer cells in vitro.

LC3B in Malignant Cells Correlates With Immune Infiltrate in Hypopharyngeal Squamous Cell Carcinoma

The objective of this study was to investigate the between autophagy activity and local immune response in hypopharyngeal squamous cell carcinoma (HSCC). Herein, we observed the expression of autophagy marker microtubule-associated protein light chain 3B (MAP1LC3B), CD8 cytotoxic T lymphocytes (CTLs), CD39 (regulatory T cells Tregs) and CD163 (tumor-associated macrophages TAMs) in HSCC, and determined the prognostic roles of CD8⁺/CD39⁺ and CD8⁺/CD163⁺ in patients with HSCC. The expression of light chain 3B (LC3B) and CD8⁺/CD39⁺ was found to be significantly lower in HSCC tissues than in adjacent non-tumor mucosa tissue samples; LC3B expression was positively correlated with the infiltration rate of CD8⁺/CD39⁺ in HSCC. Further studies revealed that the ratio of CD8⁺/CD39⁺ immune cells was negatively correlated with tumor lymph node metastasis and TNM classification, while the ratio of CD8⁺/CD163⁺ immune cells was negatively correlated with TNM classification. Moreover, the expression of LC3B was analyzed and the patients were grouped according to their immune infiltration characteristics. The 5-year cumulative survival rates of LC3B⁺, CD8⁺/CD39⁺, and CD8⁺/CD163⁺ patients were significantly higher than those of other group patients. Collectively, our studies indicated that the expression of LC3B in HSCC was correlated with the infiltration ratio of immune cells, and a change in autophagy activity may affect the cellular immunity in HSCC. The ratios of tCD8⁺/CD39⁺ and tCD8⁺/CD163⁺ may serve as prognostic factors for HSCC.

Inhibiting autophagy to prevent drug resistance and improve anti-tumor therapy

Cytotoxic drugs remain the first-line option for cancer therapy but the development of drug-resistance by tumor cells represents a primary obstacle for successful chemotherapy. Autophagy is a physiological mechanism of cell survival efficiently used by tumor cells to avoid cell death and to induce drug-resistance. It is a macromolecular process, in which cells degrade and recycle intracellular substrates and damaged organelles to alleviate cell stress caused by nutritional deprivation, hypoxia, irradiation, and cytotoxic agents, as well. There is evidence that autophagy prevents cancer during the early steps of carcinogenesis, but once transformed, these cells show enhanced autophagy capacity and use it to survive, grow, and facilitate metastasis. Current basic studies and clinical trials show the feasibility of using pharmacological or molecular blockage of autophagy to improve the anticancer therapy efficiency. In this review, we overviewed the pathways and molecular aspects of autophagy, its role in carcinogenesis, and the evidence for its role in cancer adaptation and drug-resistance. Finally, we reviewed the clinical findings on how the autophagy interference helps to improve conventional anticancer therapy.

Autophagy-Related Beclin 1 and Head and Neck Cancers

Beclin 1, a positive regulator of autophagy, behaves as a double-edged sword in tumorigenesis. Beclin 1 contributes to tumor suppression by removing defective or damaged organelles and other cellular components; however, its activity can also stimulate cancer initiation and progression. In head and neck cancer, Beclin 1 overexpression promotes autophagy, which limits DNA damage and chromosomal instability and increases necrosis and inflammation by impacting apoptotic and autophagic pathways. This paper reviews the relationship between Beclin 1, carcinogenesis and head and neck cancer prognosis.

Overexpression of S100A4 Predicts Migration, Invasion, and Poor Prognosis of Hypopharyngeal Squamous Cell Carcinoma

INTRODUCTION

Hypopharyngeal squamous cell carcinoma (HSCC) is among the most lethal tumors encountered in the head and neck and frequently involves regional metastasis. However, the mechanism underlying the aggressiveness of HSCC remains elusive. S100A4 is a well-established metastasis-promoting regulator in a variety of malignancies, but its role in HSCC has not yet been identified.

OBJECTIVES

Our objectives were to explore the expression levels of S100A4 in HSCC tumors and its association with clinicopathological parameters and the clinical prognosis of HSCC and to confirm its role in the metastatic process of the HSCC FaDu cell line in vitro.

METHODS

We assessed the expression levels of S100A4 with immunohistochemistry (IHC) in HSCC tumors (n = 71) and adjacent normal tissues (n = 44). In vitro experiments were performed to explore the impact of S100A4 knockdown on biological phenotypes of human HSCC FaDu cell line, including migration, invasion, proliferation, apoptosis, and cell cycle.

RESULTS

The expression of S100A4 was elevated in HSCC tumors compared with adjacent normal tissues and positively correlated with cervical lymph node metastasis in this HSCC patient cohort. In vitro experiments showed that S100A4 knockdown significantly impaired migration and invasion and increased the proportion of cells in G0/G1 phase with no change in proliferation or apoptosis in FaDu cells. Additionally, nuclear S100A4 expression proved to be an independent prognostic indicator in patients with HSCC.

CONCLUSION

This study demonstrated for the first time that S100A4 expression is upregulated in HSCC tumors and that this upregulation is positively correlated with cervical lymph node metastasis of this malignancy. The metastasis-promoting role of S100A4 was further validated in the HSCC FaDu cell line, indicating that S100A4 is a potential therapeutic target for HSCC. Furthermore, this study suggests that nuclear S100A4 expression could be considered a prognostic biomarker for HSCC.

Delayed effects of sulfur mustard on autophagy suppression in chemically-injured lung tissue

BACKGROUND

Autophagy is an intracellular hemostasis mechanism, responding to extracellular or intracellular stresses. Sulfur mustard (SM) induces cellular stress. Iranian soldiers exposed to SM gas, during the Iraq-Iran war, suffer from delayed complications even 30 years after exposure. In this study, for exploring the SM effect on autophagy pathway, gene and protein expression of autophagy markers are evaluated in the lung of SM-exposed people.

METHODS

52 FFPE lung tissues of SM-exposed people and 33 lung paraffin blocks of non-exposed patients to SM were selected. LC3 and Beclin-1 mRNA expressions were evaluated by QRT-PCR. LC3-B protein and LC3II/LC3I proteins ratio were detected by Immunohistochemistry and immunoblotting method. The collected data were analyzed in SPSS, and P value ≤ 0.05 was considered significant.

RESULTS

LC3 gene expression in SM-exposed subjects (median CT value = 4.97) increased about 4 fold compared with the control group (median CT value = 0.46, P = 0.025). Beclin-1 mRNA expression had not significant difference between two groups. After adjusting the confounding variables such as drug usage, LC3-B protein (P = 0.041) and LC3II/LC3I ratio (P = 0.044) were found significantly lower in the lung cells of SM-exposed group.

CONCLUSION

Upon exposure to SM gas, the lung cells are affected by acute cellular stress such as oxidative stress. The study results show that LC3 mRNA level increases in these patients, but, surprisingly, LC3-B protein via unknown mechanism has been down-regulated. N-acetyl cysteine and salbutamol drugs could induce the autophagy, and help to reduce the SM effects and improve the clinical condition of SM-injured patients.

Mode of action of granulocyte-colony stimulating factor (G-CSF) as a novel therapy for stroke in a mouse model

BACKGROUND

The FDA approved drug granulocyte-colony stimulating factor (G-CSF) displays anti-apoptotic and immunomodulatory properties with neurogenesis and angiogenic functions. It is known to demonstrate neuroprotective mechanisms against ischemic global stroke. Autophagy is a method for the degradation of intracellular components and in particular, unrestrained autophagy may lead to uncontrolled digestion of affected neurons as well as neuronal death in cerebral ischemia. Mitochondrial dynamics is vital for the regulation of cell survival and death after cerebral ischemia and an early upstream event in neuronal death is mitochondrial fission. We examined the pro-survival mechanisms of G-CSF against apoptosis resulting from autophagy, mitochondrial stress and endoplasmic reticulum (ER) stress.

METHODS

Male Swiss Webster mice (20 weeks of age) were subjected to bilateral common carotid artery occlusion (BCAO) for 30 min. After occlusion, mice were injected with G-CSF (50 μg/kg) subcutaneously for 4 days. Behavioral analysis was carried out using the corner test and locomotor activity test before animals were sacrificed on day 4 or day 7. Key proteins in ER stress, autophagy and mitochondrial stress induced apoptosis were analyzed by immunoblotting.

RESULTS

G-CSF improved neurological deficits and improved behavioral performance on corner and locomotor test. G-CSF binds to G-CSF receptors and its activation leads to upregulation of Akt phosphorylation (P-Akt) which in turn decreases levels of the ER stress sensor, GRP 78 and expression of proteins involved in ER stress apoptosis pathway; ATF6, ATF4, eIF2α, XBP1, Caspase 12 and CHOP. G-CSF treatment significantly decreased Beclin-1, an autophagy marker, and decreased mitochondrial stress biomarkers DRP1 and P53. G-CSF also up-regulated the mitochondrial fusion protein, OPA1 and anti-apoptotic protein Bcl-2 while down-regulating the pro-apoptotic proteins Bax, Bak and PUMA.

CONCLUSIONS

G-CSF is an endogenous ligand in the CNS that has a dual activity that is beneficial both in reducing acute neuronal degeneration and adding to long-term plasticity after cerebral ischemia. G-CSF treatment exerts neuroprotective effects on damaged neurons through the suppression of the ER stress and mitochondrial stress and maintains cellular homeostasis by decreasing pro-apoptotic proteins and increasing of anti-apoptotic proteins.

CCND1 silencing suppresses liver cancer stem cell differentiation through inhibiting autophagy

Liver cancer stem cells (LCSCs) are responsible for the carcinogenesis, recurrence, metastasis and chemoresistance of hepatocellular carcinoma (HCC). This study aimed to explore the role of CCND1 (Cyclin D1), an oncogene in HCC, in regulating LCSC differentiation and to elucidate whether autophagy was involved in this process. The CCND1 mRNA level was examined by qRT-PCR. The protein levels of autophagy markers (Becin-1 and LC3II) were examined by western blot to evaluate autophagy level. CD133 was used as a LCSC marker and CD133 + cell percentage in HCC cells was detected by flow cytometry. Immunohistochemistry staining was performed to detect CD133 expression in SMMC-7721 cell-implanted tumor sections. The results showed that CCND1 expression was higher in HCC cell lines than that in normal hepatocyte L02 cells. Furthermore, CCND1 overexpression increased CD133 + cell percentage and protein levels of Becin-1 and LC3II in HepG2 and SMMC-7721 HCC cells. In contrast, CCND1 silencing exerted the opposite effect. Moreover, treatment with the autophagy activator rapamycin effectively abrogated the CCND1 silencing-reduced CD133 + cell percentage. Further in vivo assays demonstrated that CCND1 silencing decreased expression of CD133, Becin-1 and LC3II in xenograft tumors of SMMC-7721 cells. Taken together, CCND1 silencing suppresses LCSC differentiation through inhibiting autophagy.

Intracarotid cold saline infusion contributes to neuroprotection in MCAO‑induced ischemic stroke in rats via serum and glucocorticoid‑regulated kinase 1

Intracarotid cold saline infusion (ICSI) brings about neuroprotective effects in ischemic stroke. However, the involvement of serum and glucocorticoid‑regulated kinase 1 (SGK1) in the underlying mechanism of ICSI is not fully understood; therefore, we used the rat middle cerebral artery occlusion (MCAO) model to investigate the neuroprotective effects of ICSI on ischemic stroke in rats, as well as the involvement of SGK1 in these effects. ICSI decreased infarct size and brain swelling, as determined by 2,3,5‑triphenyltetrazolium chloride staining and the dry‑wet weight method, respectively. The results of terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL) and Nissl staining showed that ICSI also suppressed apoptosis and increased the relative integral optical density (IOD) values of Nissl bodies in the rat MCAO model. Regarding the mechanism, the results of immunohistochemistry and western blotting revealed that ICSI upregulated SGK1 expression and downregulated beclin‑1 and LC‑3 expression in the rat MCAO model. In addition, SGK1 knockdown increased ICSI‑mediated infarct size and brain swelling, promoted apoptosis, and reduced the IOD values of Nissl bodies in the rat MCAO model. In addition, we found that SGK1 knockdown upregulated beclin‑1 and LC‑3 expression mediated by ICSI. Overall, ICSI had a neuroprotective effect on ischemic stroke after reperfusion by upregulating SGK1 and inhibiting autophagy.

The autophagy-related genes Beclin1 and LC3 in the prognosis of pancreatic cancer

PURPOSE

To investigate the role of the autophagy-related genes Beclin1 and LC3 in the prognosis of pancreatic cancer.

METHODS

A total of 86 pancreatic cancer tissues and 84 paired, adjacent normal pancreatic tissues were collected from 86 patients who underwent pancreatic resection surgery in our hospital from January 2009 to August 2011. Demographic data including age, gender, family cancer history, and clinic-pathological characteristics, including tumor diameter, differential, TNM staging and lymphatic metastasis were collected. The expressions of Beclin1 and LC3 were determined using both immunohistochemistry (IHC) and RT-qPCR.

RESULTS

The expression levels of both Beclin1 and LC3 mRNA and proteins were significantly up-regulated in the tumor tissues compared with the normal tissues. Higher expressions of Beclin1 and LC3 were found in the tumor tissues of patients with TNM stages III~IV, patients with lymphatic metastasis, and patients who died. Meanwhile Beclin1 and LC3 correlated with TNM stage, differential condition, and the patients' lymphatic metastasis rates. A survival analysis showed that patients with low expressions of Beclin1 and LC3 had longer survival times, and both the Beclin1 and LC3 genes were independent risk factors for 5-year mortality in pancreatic cancer patients.

CONCLUSION

The Beclin1 and LC3 genes correlate with the tumor stage, metastasis conditions, and pancreatic cancer patients' mortality.

CS-PEI/Beclin-siRNA Downregulate Multidrug Resistance Proteins and Increase Paclitaxel Therapeutic Efficacy against NSCLC

Paclitaxel (PTX) is a widely used chemotherapy drug; however, frequent use causes multidrug resistance (MDR), which limits the utility of PTX against advanced non-small-cell lung cancer (NSCLC). PTX-resistant subline (NCI-H23-TXR) was established in vitro by exposing NCI-H23 cells to gradually increased concentrations of PTX in culture medium. Distinct Beclin expression of autophagy level was observed between resistant NCI-H23-TXR and parental NCI-H23 cells. Beclin-small interfering RNA (siRNA) was selected to restore sensitivity of PTX against NCI-H23-TXR. Chondroitin sulfate-polyethylenimine (CS-PEI) was constructed for delivery and protection of Beclin-siRNA. To delineate the underlying molecular mechanism of Beclin knockdown, we analyzed different MDR expression proteins of two cells using western blot, and the corresponding genes were confirmed by real-time PCR. Compared with NCI-H23, NCI-H23-TXR had higher expression levels in P-glycoprotein (P-gp) and multidrug resistance protein 7 (ABCC10). Knockdown of Beclin simultaneously inhibited P-gp and ABCC10, and renewed the sensitivity of PTX against NCI-H23-TXR. Research on zebrafish embryos revealed that tumor sizes decreased in NCI-H23 tumor xenografts but remained intact in NCI-H23-TXR tumor xenografts as zebrafish were treated with 1 μg/mL PTX. In contrast, the tumor sizes decreased in NCI-H23-TXR tumor xenografts with zebrafish pre-transfected with CS-PEI/Beclin-siRNA followed by the same treatment of PTX. The role of autophagy was associated with MDR development. This study paves the way for a new avenue of PTX in MDR-related lung cancer therapy using CS-PEI as a gene delivery carrier.

Beclin1 inhibition enhances paclitaxel‑mediated cytotoxicity in breast cancer in vitro and in vivo

Beclin1, a key regulator of autophagy, has been demonstrated to be associated with cancer cell resistance to chemotherapy. Paclitaxel is a conventional chemotherapeutic drug used in the clinical treatment of breast cancer. However, the function and mechanism of Beclin1 in paclitaxel‑mediated cytotoxicity in breast cancer are not well defined. The present study demonstrated that paclitaxel suppressed cell viability and Beclin1 expression levels in BT‑474 breast cancer cells in a dose‑ and time‑dependent fashion. Compared with the control, the knockdown of Beclin1 significantly enhanced breast cancer cell death via the induction of caspase‑dependent apoptosis following paclitaxel treatment in vitro (P<0.05). In a BT‑474 xenograft model, paclitaxel achieved substantial inhibition of tumor growth in the Beclin1 knockdown group compared with the control group. Furthermore, analysis of the publicly available Gene Expression Omnibus datasets revealed a clinical correlation between Beclin1 levels and the response to paclitaxel therapy in patients with breast cancer. Collectively, the present results suggest that Beclin1 protects breast cancer cells from apoptotic death. Thus, the inhibition of Beclin1 may be a novel way to improve the effect of paclitaxel. Additionally, Beclin1 may function as a favorable prognostic biomarker for paclitaxel treatment in patients with breast cancer.

Targeting AR-Beclin 1 complex-modulated growth factor signaling increases the antiandrogen Enzalutamide sensitivity to better suppress the castration-resistant prostate cancer growth

While the recently developed antiandrogen Enzalutamide (Enz) can extend survival for 4.8 months in castration-resistant prostate cancer (CRPC) patients, eventually most of these CRPC patients may develop resistance to the Enz without a clear mechanism. Here we found the expression of Beclin 1 was decreased in both Enz-resistant (EnzR) cell lines (EnzR1-C4-2 and EnzR2-C4-2B) as compared to their parental Enz-sensitive (EnzS) (EnzS1-C4-2 and EnzS2-C4-2B) cells, and targeting the Beclin 1 could lead to increase the Enz-sensitivity in these two CRPC cell lines. Mechanism dissection revealed that Enz might function via altering the interaction between Beclin 1 and the androgen receptor (AR) to decrease the activity of Beclin 1/Vps15/Vps34 complex thus increasing the ERK-mediated growth factor signaling to alter the Enz sensitivity. Interrupting the AR-Beclin 1/ERK signaling with ectopic BECN1 or ERK inhibitor led to alter the Enz sensitivity in both EnzR1-C4-2 and EnzR2-C4-2B cells compared to EnzS1-C4-2 and EnzS2-C4-2B cells, respectively. Together, these results suggest that targeting this newly identified AR-Beclin 1 complex-mediated ERK growth factor signaling with small molecule ERK inhibitor may help potentially develop new therapies to better suppress the EnzR CRPC.

Autophagy Induction by HIV-Tat and Methamphetamine in Primary Midbrain Neuronal Cells of Tree Shrews via the mTOR Signaling and ATG5/ATG7 Pathway

Background: Addictive stimulant drugs, such as methamphetamine (METH), increase the risk of exposure to the human immunodeficiency virus-1 (HIV-1) infection and thus predispose individuals to the development of HIV-associated neurocognitive disorders (HANDs). Previous studies have indicated that HIV-Tat (the transactivator of transcription) and METH can synergistically induce autophagy in SH-SY5Y neuroblastoma cells and that autophagy plays a pivotal role in the neuronal dysfunction in HANDs. However, the underlying mechanism of METH-and HIV-Tat-induced neuronal autophagy remains unclear. Methods: We cultured primary midbrain neuronal cells of tree shrews and treated them with METH and HIV-Tat to study the role of METH and HIV-Tat in inducing autophagy. We evaluated the effects of the single or combined treatment of METH and HIV-Tat on the protein expressions of the autophagy-related genes, including Beclin-1 and LC3B, ATG5, and ATG7 in METH and HIV-Tat-induced autophagy. In addition, the presence of autophagosomes in the METH and/or HIV-Tat treatment was revealed using transmission electron microscopy. Results: The results indicated that METH increased the protein levels of LC3B and Beclin-1, and these effects were significantly enhanced by HIV-Tat. Moreover, the results suggested that ATG5 and ATG7 were involved in the METH and HIV-Tat-induced autophagy. In addition, it was found that mTOR inhibition via pharmacological intervention could trigger autophagy and promote METH and HIV-Tat-induced autophagy. Discussion: Overall, this study contributes to the knowledge of the molecular underpinnings of METH and HIV-Tat-induced autophagy in primary midbrain neuronal cells. Our findings may facilitate the development of therapeutic strategies for METH-and HIV-Tat-induced autophagy in HANDs.

Distinct subgroup of the Ras family member 3 (DIRAS3) expression impairs metastasis and induces autophagy of gastric cancer cells in mice

Purpose

Distinct subgroup of the Ras family member 3 (DIRAS3), also called Aplasia Ras homolog member I, is a tumor suppressor gene that induces autophagy in several cancer cell lines.

Methods

This study analyzed DIRAS3, and markers of autophagy (p62, and LC3B-II) in surgically resected GC samples from 420 patients. The promotion of autophagy by DIRAS3 in gastric cancer (GC) cells was explored, which might explain its inhibitory role in gastric cancer cells.

Results

DIRAS3 expression in GC was positively correlated with LC3B-II amount, and negatively with metastasis; DIRAS3 and p62 levels were independent prognostic factors in GC. Overexpression of DIRAS3 in BGC-823 cells induced autophagy, led to decreased proliferation, cell cycle arrest in G0/G1 phase, increased apoptosis, and impaired migration and invasion. While knockdown of DIRAS3 promoted proliferation and migration in MKN-45 cells. Overexpression of DIRAS3 in BGC-823 cells elevated autophagy levels in subcutaneous xenograft and inhibited tumor growth in mice; the hematogenous liver and lung metastasis of cancer cells were also suppressed.

Conclusions

In conclusion, the results suggest DIRAS3 may play a role in affecting proliferation and metastatic potential of GC cells, which may be associated with its involvement in autophagy regulation.

Prognostic and clinicopathological significance of Beclin-1 in non-small-cell lung cancer: a meta-analysis

Background

Autophagy plays a key role in the development of non-small-cell lung cancer (NSCLC). Beclin-1 is essential for the initiation and regulation of autophagy. Accumulated studies have investigated the prognostic role of Beclin-1 in NSCLC, but conclusions remain controversial. Therefore, we conducted this meta-analysis to assess the potential significance of Beclin-1 in NSCLC.

Materials and methods

PubMed and Embase databases were searched for eligible studies published before December 31, 2017. Odds ratio (OR) was pooled to evaluate the clinicopathological significance of Beclin-1 in NSCLC. Hazard ratio (HR) was adopted to assess the association of Beclin-1 with overall survival (OS).

Results

Eight studies involving 1,159 patients were included in this meta-analysis. The pooled results showed that high Beclin-1 expression was significantly correlated with earlier tumor grade (OR=0.54, 95% CI: 0.36-0.81, P=0.003), less nodal involvement (OR=0.56, 95% CI: 0.37-0.86, P=0.007), earlier TNM stage (OR=0.62, 95% CI: 0.43-0.89, P=0.010), smaller tumor size (OR=0.54, 95% CI: 0.36-0.81, P=0.003), better differentiation (OR=0.48, 95% CI: 0.36-0.64, P<0.001), and less recurrence (OR=0.24, 95% CI: 0.14-0.41, P<0.001). Moreover, high level of Beclin-1 was significantly associated with better OS in NSCLC (HR=0.41, 95% CI: 0.26-0.64, P<0.001).

Conclusion

Our meta-analysis suggests that high Beclin-1 expression predicts a better clinicopathological status and a better prognosis in NSCLC. Beclin-1 might act as a promising prognostic biomarker for NSCLC.

Expression of glucose transporter-1, hypoxia inducible factor-1α and beclin-1 in head and neck cancer and their implication

Previous studies have demonstrated that oncogenes, tumor suppressor genes, and hypoxic factors are involved in the pathogenesis, development, and progression of head and neck cancer. In this study, we investigated the expression of HIF-1α, GLUT-1, and beclin-1 in head and neck cancers and analyzed the relationship between these markers and clinicopathologic factors. 44 paraffin-embedded samples of head and neck cancer specimens were collected. The expression of HIF-1α, GLUT-1, Ki 67, and beclin-1 was detected by immunohistochemical technique. The expression of HIF-1α, GLUT-1, Ki 67, and beclin-1 in head and neck cancers were higher than those for the corresponding paracancerous tissues. Stratification analysis revealed a significant difference between GLUT-1 expression in older patients with laryngeal/hypopharyngeal SCC and younger patients with laryngeal/hypopharyngeal SCC. No significant differences in GLUT-1 or beclin-1 or HIF-1α or Ki 67 expression were found between clinicopathologic characteristics, including lymph node metastasis, T stage, clinical stage, and location, for any of the cancer types studied. Pearson analysis revealed that there was a negative correlation between beclin-1 and HIF-1α (r=0.482, P=0.001), and between beclin-1 and Ki-67 (r=-0.366, P=0.0151). Whether beclin-1 plays a role in carcinogenesis in head and neck cancers should be further studied.

Ligand activated progesterone receptor B drives autophagy-senescence transition through a Beclin-1/Bcl-2 dependent mechanism in human breast cancer cells

Loss of progesterone-receptors (PR) expression is associated with breast cancer progression. Herein we provide evidence that OHPg/PR-B through Beclin-1 evoke autophagy-senescence transition, in breast cancer cells. Specifically, OHPg increases Beclin-1 expression through a transcriptional mechanism due to the occupancy of Beclin-1 promoter by PR-B, together with the transcriptional coactivator SRC-2. This complex binds at a canonical half progesterone responsive element, which is fundamental for OHPg effects, as shown by site-directed mutagenesis. Beside, OHPg via non-genomic action rapidly activates JNK, which phosphorylates Bcl-2, producing the functional release from Beclin-1 interaction. This is not linked to an efficient autophagic flux, since p62 levels, marker of degradation via lysosomes, were not reduced after sustained OHPg stimulus. Instead, the cell cycle inhibitor p27 was induced, together with an irreversible G1 arrest, hallmark of cellular senescence. Specifically the increase of senescence-associated β-galactosidase activity was blocked by Bcl-2 siRNA but also by Beclin-1 siRNA. Collectively these findings support the importance of PR-B expression in breast cancer cells, thus targeting PR-B may be a useful strategy to provide additional approaches to existing therapies for breast cancer patients.

AB209630, a long non-coding RNA decreased expression in hypopharyngeal squamous cell carcinoma, influences proliferation, invasion, metastasis, and survival

Long noncoding RNAs (lncRNAs) are associated with the development, progression, and prognosis of human cancers. However, the clinical significance and biological function of lncRNAs in hypopharyngeal squamous cell carcinoma (HSCC) remain largely unknown. We characterized the novel lncRNA AB209630 in vivo and in vitro. First, using qRT-PCR, we evaluated whether AB209630 levels differ between HSCC tissues/cell lines and adjacent normal tissues/cell lines. We then assessed whether AB209630 expression levels stimulate or inhibit proliferation, invasion, apoptosis, and metastasis in vitro. Finally, we investigated whether AB209630 levels in tumor tissues were associated with survival outcomes. Our results demonstrated that AB209630 levels were markedly lower in HSCC tissues and cells than in normal tissues and cells, and increased expression of AB209630 level significantly inhibited growth, metastasis, and invasion and stimulated apoptosis in vitro. In addition, patients with decreased expression of AB209630 had a significantly poorer prognosis than those with high AB209630 expression. These data suggest that increased expression of AB209630 might either stimulate or inhibit biological activities involved in HSCC development, indicating a potential application of AB209630 in future treatment for this disease. This study suggest that AB209630 functions as a tumor suppressor in HSCC, and its decreased expression may help predict a poor prognostic outcome of HSCC. Our future work will focus on the mechanisms of whether and how AB209630 as a tumor suppressor gene is involved in HSCC development.

Autophagy analysis in oral carcinogenesis

OBJECTIVE

The aim of this study was to evaluate the levels of autophagy in oral leukoplakia and squamous cell carcinoma and to correlate with clinical pathological features, as well as, the evolution of these lesions.

METHODOLOGY

7 Normal oral mucosa, 51 oral leukoplakias, and 120 oral squamous cell carcinomas (OSCC) were included in the study. Histological sections of the mucosa and leukoplakias were evaluated throughout their length, while the carcinomas were evaluated using Tissue Microarray. After the immunohistochemical technique, LC3-II positive cells were quantified in the different epithelial layers of the mucosa and leukoplakias and in the microarrays of the squamous cell carcinomas. The correlation between positive cells with the different clinical-pathological variables and with the evolution of the lesions was tested using the t test, ANOVA, and Kaplan-Meier survival analysis.

RESULTS

We observed increased levels of autophagy in the oral squamous cell carcinomas (p<0.001) in relation to the other groups, but without any association with poorer evolution or survival of these patients. Among the leukoplakias, we observed a higher percentage of positive cells in the intermediate layer of the dysplastic leukoplakias (p=0.0319) and in the basal layer of lesions with poorer evolution (p=0.0133).

CONCLUSION

The levels of autophagy increased during the process of oral carcinogenesis and are correlated with poorer behavior of the leukoplakias.

Kinase-driven metabolic signalling as a predictor of response to carboplatin-paclitaxel adjuvant treatment in advanced ovarian cancers

BACKGROUND

The biological mechanisms underlying early- and advanced-stage epithelial ovarian cancers (EOCs) are still poorly understood. This study explored kinase-driven metabolic signalling in early and advanced EOCs, and its role in tumour progression and response to carboplatin-paclitaxel treatment.

METHODS

Tumour epithelia were isolated from two independent sets of primary EOC (n=72 and 30 for the discovery and the validation sets, respectively) via laser capture microdissection. Reverse phase protein microarrays were used to broadly profile the kinase-driven metabolic signalling of EOC with particular emphasis on the LBK1-AMPK and AKT-mTOR axes. Signalling activation was compared between early and advanced lesions, and carboplatin-paclitaxel-sensitive and -resistant tumours.

RESULTS

Advanced EOCs were characterised by a heterogeneous kinase-driven metabolic signature and decreased phosphorylation of the AMPK-AKT-mTOR axis compared to early EOC (P<0.05 for AMPKα T172, AMPKα1 S485, AMPKβ1 S108, AKT S473 and T308, mTOR S2448, p70S6 S371, 4EBP1 S65, GSK-3 α/β S21/9, FOXO1 T24/FOXO3 T32, and FOXO1 S256). Advanced tumours with low relative activation of the metabolic signature and increased FOXO1 T24/FOXO3 T32 phosphorylation (P=0.041) were associated with carboplatin-paclitaxel resistance.

CONCLUSIONS

If validated in a larger cohort of patients, the decreased AMPK-AKT-mTOR activation and phosphorylation of FOXO1 T24/FOXO3 T32 may help identify carboplatin-paclitaxel-resistant EOC patients.

Molecular mechanisms of anticancer activity of deoxyelephantopin in cancer cells

Background

Deoxyelephantopin (DOE) is a natural bioactive sesquiterpene lactone from Elephantopus scaber, a traditionally relevant herb in Chinese and Indian medicine. It has shown promising anticancer effects against a broad spectrum of cancers.

Methods

We examined the effect of DOE on growth, autophagy, apoptosis, cell cycle progression, metastasis, and various molecular signaling pathways in cancer cells, and endeavored to decipher the molecular mechanisms underlying its effect. The cytotoxicity of DOE was examined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) and colony formation assays. The antimetastatic potential of DOE was identified by wound closure, as well as invasion and migration assays. The expression of mRNAs and proteins related to cytotoxicity in cancer cells induced by DOE was investigated using reverse transcription-polymerase chain reaction, flow cytometry, and Western blot analysis.

Results

DOE showed significant cytotoxicity and induced apoptosis in cancer cells. DOE promoted the autophagy of HCT 116 and K562 cells. DOE arrested cell cycle progression in the G2/M phase. DOE treatment caused activation of caspase-8, -9, -3 and -7, reactive oxygen species production, and cleavage of cleavage of poly-ADP-ribose polymerase (PARP), the markers of apoptosis. Moreover, apoptosis induction was associated with mitochondrial permeability and endoplasmic reticulum stress. Treatment of cancer cells with DOE inhibited mitogen-activated protein kinases, nuclear factor-kappa B, phosphatidylinositol 3-kinase (PI3K/Akt), and β-catenin signaling. Furthermore, treatment of DOE increased the expression of p53, phospho-Jun amino-terminal kinases (p-JNK), and p-p38 and decreased the expression of phospho-signal transducer and activator of transcription 3 (p-STAT3) and phospho-mammalian target of rapamycin (p-mTOR) in cancer cells. DOE downregulated matrix metalloproteinase (MMP-2) and MMP-9, urokinase-type plasminogen activator (uPA), and urokinase-type plasminogen activator receptor (uPAR) mRNA levels in cancer cells.

Conclusion

These findings concluded that DOE may be useful as a chemotherapeutic agent against cancer.

Antitumor agent 25-epi Ritterostatin GN1N induces endoplasmic reticulum stress and autophagy mediated cell death in melanoma cells

Metastatic melanoma is the most aggressive of all skin cancers and is associated with poor prognosis owing to lack of effective treatments. 25-epi Ritterostatin G_N1_N is a novel antitumor agent with yet undefined mechanisms of action. We sought to delineate the antitumor mechanisms of 25-epi Ritterostatin G_N1_N in melanoma cells to determine the potential of this compound as a treatment for melanoma. Activation of the endoplasmic reticulum (ER) stress protein glucose-regulated protein 78 (GRP78) has been associated with increased melanoma progression, oncogenic signaling, drug resistance, and suppression of cell death. We found that 25-epi Ritterostatin G_N1_N induced cell death in melanoma cells at nanomolar concentrations, and this cell death was characterized by inhibition of GRP78 expression, increased expression of the ER stress marker CHOP, loss of mitochondrial membrane potential, and lipidation of the autophagy marker protein LC3B. Importantly, normal melanocytes exhibited limited sensitivity to 25-epi Ritterostatin G_N1_N. Subsequent in vivo results demonstrated that 25-epi Ritterostatin G_N1_N reduced melanoma growth in mouse tumor xenografts and did not affect body weight, suggesting minimal toxicity. In summary, our findings indicate that 25-epi Ritterostatin G_N1_N causes ER stress and massive autophagy, leading to collapse of mitochondrial membrane potential and cell death in melanoma cells, with minimal effects in normal melanocytes. Thus, 25-epi Ritterostatin G_N1_N is a promising anticancer agent that warrants further investigation.

Autophagy is associated with chemoresistance in neuroblastoma

Background

Neuroblastoma (NB) is a frequent pediatric tumor characterized by a poor prognosis where a majority of tumors progress despite intensive multimodality treatments. Autophagy, a self-degradative process in cells, could be induced by chemotherapy and be associated with chemoresistance. The aim of this study was to determine whether: 1) autophagy is present in NB, 2) chemotherapy modified its levels, and 3) its inhibition decreased chemoresistance.

Methods

Immunohistochemical stainings were performed on samples from 184 NB patients in order to verify the expression of LC3B, a specific marker for autophagy, and Beclin 1, a positive regulator of autophagy. In addition, we performed an in vitro study with six NB cell lines and six drugs (vincristine, doxorubicin, cisplatin temozolomide, LY294002 and syrolimus). Inhibition of autophagy was performed using ATG5 knockdown cells or hydroxychloroquine (HCQ). Cell survival was measured using the MTT cell proliferation assay. Autophagy was detected by monodansylcadaverine, confocal microscopy and Western blot. In vivo study with tumor xenografts in NSG mice was performed.

Results

Our results have indicated that autophagy was present at low levels in NB and was not a prognostic factor, while Beclin 1 was highly expressed in children with poor NB prognosis. However, autophagy levels increased after chemotherapy in vitro and in vivo. Tumor progression was significantly decreased in mice treated with a combination of HCQ and vincristine.

Conclusions

Taken together, autophagy is present in NB, induced by chemotherapy and associated with chemoresistance, which is significantly reduced by its inhibition. Therefore, targeting autophagy represents a very attractive approach to develop new therapeutic strategies in NB.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2906-9) contains supplementary material, which is available to authorized users.

Inflammation modulates LC3 expression in human preterm delivery

OBJECTIVE

Autophagy is an inducible intracellular process acting under stressor conditions, such as infections, inflammation and hypoxia. The aim of the present study was to analyze autophagy expression in preterm delivered human placenta.

METHODS

Autophagy marker LC3 was analyzed in 25 consecutive human placentas delivered before 34 weeks of gestation, analyzed by immunohistochemistry, immunofluorescence and quantitative real-time PCR, according to the histologic classification of preterm delivery (PTD) (cases with or without placental inflammatory lesions).

RESULTS

LC3 expression was observed both in cases with and without inflammatory lesions. In cases with histological inflammation, strong immunoreactivity for LC3 autophagic marker was observed in the inflammatory cell infiltration composed by neutrophils. In all PTD cases, trophoblastic cells in chorion laeve express LC3, with variable staining intensity: a significant reduction of LC3 expression was observed in chorion laeve of PTD with histological inflammation compared to PTD without inflammatory lesions. Moreover, the decrement of LC3 staining was observed to be associated to the increasing severity of the histological signs of fetal inflammatory response.

CONCLUSIONS

Our data show that the expression of LC3 varies depending on different histological features, indicating an interesting and possibly clinically relevant relation between autophagy expression levels and the inflammatory status.

Specific c-Jun target genes in malignant melanoma

A fundamental event in the development and progression of malignant melanoma is the de-regulation of cancer-relevant transcription factors. We recently showed that c-Jun is a main regulator of melanoma progression and, thus, is the most important member of the AP-1 transcription factor family in this disease. Surprisingly, no cancer-related specific c-Jun target genes in melanoma were described in the literature, so far. Therefore, we focused on pre-existing ChIP-Seq data (Encyclopedia of DNA Elements) of 3 different non-melanoma cell lines to screen direct c-Jun target genes. Here, a specific c-Jun antibody to immunoprecipitate the associated promoter DNA was used. Consequently, we identified 44 direct c-Jun targets and a detailed analysis of 6 selected genes confirmed their deregulation in malignant melanoma. The identified genes were differentially regulated comparing 4 melanoma cell lines and normal human melanocytes and we confirmed their c-Jun dependency. Direct interaction between c-Jun and the promoter/enhancer regions of the identified genes was confirmed by us via ChIP experiments. Interestingly, we revealed that the direct regulation of target gene expression via c-Jun can be independent of the existence of the classical AP-1 (5´-TGA(C/G)TCA-3´) consensus sequence allowing for the subsequent down- or up-regulation of the expression of these cancer-relevant genes. In summary, the results of this study indicate that c-Jun plays a crucial role in the development and progression of malignant melanoma via direct regulation of cancer-relevant target genes and that inhibition of direct c-Jun targets through inhibition of c-Jun is a potential novel therapeutic option for treatment of malignant melanoma.

Chloroquine enhances the efficacy of cisplatin by suppressing autophagy in human adrenocortical carcinoma treatment

BACKGROUND

It has been demonstrated that chloroquine (CQ) enhances the efficacy of chemotherapy. However, little is known about whether CQ could enhance the efficacy of cisplatin (DDP) in the treatment of adrenocortical carcinoma (ACC). In this study, we explore the efficacy and mechanism by which CQ affects DDP sensitivity in human ACC in vitro and in vivo.

METHODS

The autophagic gene Beclin-1 expression was detected by immunohistochemistry, and the protein levels were analyzed using immunoblotting assays of ACC tissues and normal adrenal cortex tissues. The ACC SW13 cells were treated with DDP and/or CQ. The cell viability assay was performed using the MTT method. Qualitative autophagy detection was performed by monodansylcadaverine staining of autophagic vacuoles. Annexin V-fluorescein isothiocyanate/propidium iodide double staining was used to count cell apoptosis by flow cytometry. The autophagy-related protein (Beclin-1, LC3, and p62) and apoptosis relative protein (Bax and Bcl-2) levels were evaluated with Western blot analysis. Furthermore, a murine model of nude BALB/c mice bearing SW13 cell xenografts was established to evaluate the efficacy of concomitant therapy.

RESULTS

The expression of the autophagic gene Beclin-1 was significantly downregulated in ACC tissues compared to normal adrenal cortex tissues. The Beclin-1 protein level in ACC tissues was lower than that in normal adrenal cortex tissues (P<0.05). In vitro concomitant therapy (DDP and CQ) was more effective in restraining SW13 cell proliferation. DDP could promote cell apoptosis and induce autophagy in SW13 cells. Concomitant therapy further promoted cell apoptosis by inhibiting autophagy. In vivo, we found that concomitant therapy was more potent than DDP monotherapy in inhibiting the growth of xenografted tumors and prolonging the survival of tumor-bearing mice.

CONCLUSION

The antitumor ability of DDP was related to autophagy activity, and the concomitant therapy (DDP and CQ) could be an optimal strategy for treating ACC.

The role of autophagy in squamous cell carcinoma of the head and neck

Half a million new head and neck cancers are diagnosed each year worldwide. Although traditionally thought to be triggered by alcohol and smoking abuse, there is a growing subset of oropharyngeal cancers driven by the oncogenic human papilloma virus (HPV). Despite advances in both surgical and non-surgical treatment strategies, survival rates have remained relatively static emphasising the need for novel therapeutic approaches. Autophagy, the principal catabolic process for the lysosomal--mediated breakdown of cellular products is a hot topic in cancer medicine. Increasing evidence points towards the prognostic significance of autophagy biomarkers in solid tumours as well as strategies through which to harness autophagy modulation to promote tumour cell death. However, the role of autophagy in head and neck cancers is less well defined. In the present review, we summarise the current understanding of autophagy in head and neck cancers, revealing key areas for future translational research.

The synthetic progesterone Norgestrel is neuroprotective in stressed photoreceptor-like cells and retinal explants, mediating its effects via basic fibroblast growth factor, protein kinase A and glycogen synthase kinase 3β signalling

The synthetic progesterone Norgestrel has been shown to have proven neuroprotective efficacy in two distinct models of retinitis pigmentosa: the rd10/rd10 (B6.CXBI-Pde6b(rd10)/J) mouse model and the Balb/c light-damage model. However, the cellular mechanism underlying this neuroprotection is still largely unknown. Therefore, this study aimed to examine the downstream signalling pathways associated with Norgestrel both in vitro and ex vivo. In this work, we identify the potential of Norgestrel to rescue stressed 661W photoreceptor-like cells and ex vivo retinal explants from cell death over 24 h. Norgestel is thought to work through an upregulation of neuroprotective basic fibroblast growth factor (bFGF). Analysis of 661W cells in vitro by real-time polymerase chain reaction (rt-PCR), enzyme-linked immunosorbent assay (ELISA) and Western blotting revealed an upregulation of bFGF in response to Norgestrel over 6 h. Specific siRNA knockdown of bFGF abrogated the protective properties of Norgestrel on damaged photoreceptors, thus highlighting the crucial importance of bFGF in Norgestrel-mediated protection. Furthermore, Norgestrel initiated a bFGF-dependent inactivation of glycogen synthase kinase 3β (GSK3β) through phosphorylation at serine 9. The effects of Norgestrel on GSK3β were dependent on protein kinase A (PKA) pathway activation. Specific inhibition of both the PKA and GSK3β pathways prevented Norgestrel-mediated neuroprotection of stressed photoreceptor cells in vitro. Involvement of the PKA pathway following Norgestrel treatment was also confirmed ex vivo. Therefore, these results indicate that the protective efficacy of Norgestrel is, at least in part, due to the bFGF-mediated activation of the PKA pathway, with subsequent inactivation of GSK3β.

Expression and clinical significance of Beclin-1 in gastric cancer tissues of various clinical stages

Autophagy is a common phenomenon in cancer metabolism. However the mechanism and guiding significance of autophagy in the development of gastric cancer has remained to be elucidated. In the present study, 75 gastric cancer tissue specimens were collected at The China Japan Union Hospital of Jilin University (Changchun, China). Of these samples, 16 cases were stage 1, 40 stage 2 and 19 stage 3. Polymerase chain reaction and western blotting were used to detect the messenger RNA and protein expression of Beclin-1, a significant protein associated with cellular autophagy. It was found that expression of Beclin-1 in cancer tissues from stages 1 and 2 was higher, while in stage 3 cases levels were significantly lower than that of adjacent normal tissues. In addition, the infiltration of inflammatory cytokines was also increased in stage 1 and 2 cases. In vitro studies revealed that following stimulation with interferon-γ (IFN-γ), autophagy-associated proteins Beclin-1 and microtubule-associated protein light chain 3 were activated. Furthermore, activation of autophagy inhibited xenograft growth in nude mice. The results of these in vivo and in vitro experiments indicated that in gastric cancer tissues, autophagy was downregulated following the development of cancer tissue and that inflammation may be a significant factor in this process. IFN-γ may be involved in the mediation of this process and thus present a novel target for the treatment of gastric cancer.

The Protective Role of Autophagy in Human Vocal Fold Fibroblasts under Cigarette Smoke Extract Exposure: A New Insight into the Study of Reinke's Edema

BACKGROUND/AIMS

Reinke's edema (RE), one of the most common benign lesions of the human vocal folds, has been associated with cigarette smoking. We have observed an abundant number of autophagosomes in the cytoplasm of fibroblasts in the lamina propria of human vocal folds under transmission electron microscopy in RE tissue. Thus, we conducted a study about autophagy induced by cigarette smoke extract (CSE) exposure in cultured human vocal fold fibroblasts (hVFFs).

METHODS

Sampled tissues were cultured and exposed to varying levels of CSE. Immunochemistry staining and Western blot analyses were then performed on the cultures.

RESULTS

We demonstrated that CSE significantly promoted intracellular reactive oxygen species accumulation and reduced the viability of hVFFs in a concentration-dependent manner. Both immunocytochemistry and Western blot analysis showed increased expression of the autophagy marker type II-membrane-associated light chain 3 in fibroblasts following 24 h of CSE exposure, indicating the upregulation of autophagy activity. Furthermore, the results demonstrate that the induction of autophagy played a protective role in hVFFs exposed to CSE.

CONCLUSION

Autophagy can be induced by CSE in hVFFs, and it is a protective response of hVFFs to the exposure of CSE. This study provides a new insight into the process involved in the development of RE.

Expression of Beclin Family Proteins Is Associated with Tumor Progression in Oral Cancer

Background

Beclin 1 and Beclin 2 are autophagy-related proteins that show similar amino acid sequences and domain structures. Beclin 1 established the first connection between autophagy and cancer. However, the role of Beclin 2 in cancer is unclear. The aims of this study were to analyze Beclin 1 and Beclin 2 expressions in oral cancer tissues and in cell lines, and to evaluate their possible roles in cancer progression.

Methods

We investigated Beclin 1 and Beclin 2 expressions by immunohistochemistry in 195 cases of oral cancer. The prognostic roles of Beclin 1 and Beclin 2 were analyzed statistically. In vitro, overexpression and knockdown of Beclin proteins were performed on an oral cancer cell line, SAS. The immunofluorescence and autophagy flux assays confirmed that Beclin proteins were involved in autophagy. The impacts of Beclin 1 and Beclin 2 on autophagy and tumor growth were evaluated by conversion of LC3-I to LC3-II and by clonogenic assays, respectively.

Results

Oral cancer tissues exhibited aberrant expressions of Beclin 1 and Beclin 2. The cytoplasmic Beclin 1 and Beclin 2 expressions were unrelated in oral cancer tissues. In survival analyses, high cytoplasmic Beclin 1 expression was associated with low disease specific survival, and negative nuclear Beclin 1 expression was associated with high recurrent free survival. Patients with either high or low cytoplasmic Beclin 2 expression had significantly lower overall survival and disease specific survival rates than those with moderate expression. In oral cancer cells, overexpression of either Beclin 1 or Beclin 2 led to autophagy activation and increased clonogenic survival; knockdown of Beclin 2 impaired autophagy and increased clonogenic survival.

Conclusions

Our results indicated that distinct patterns of Beclin 1 and Beclin 2 were associated with aggressive clinical outcomes. Beclin 1 overexpression, as well as Beclin 2 overexpression and depletion, contributed to tumor growth. These findings suggest Beclin proteins are associated with tumorigenesis.

Proteomic identification of alpha-2-HS-glycoprotein as a plasma biomarker of hypopharyngeal squamous cell carcinoma

Hypopharyngeal squamous cell carcinoma (HSCC) has very poor prognosis compared with other head and neck squamous cell carcinomas. Late-stage diagnosis of HSCC increases mortality. Therefore, more effective biomarkers for early diagnosis of HSCC are necessary. Unfortunately, appropriate biomarkers for clinical diagnosis and prognosis have not been identified yet. However, recent progresses in quantitative proteomics have offered opportunities to identify plasma proteins as biomarkers for HSCC. In the present study, plasma samples were analyzed by two-dimensional differential gel electrophoresis (2D-DIGE), and differentially expressed proteins were identified by matrix assisted laser desorption ionization-time of flight/time of flight mass spectrometry (MALDI-TOF/TOF MS). A total of 26 proteins representing 12 unique gene products were identified. The up-regulation proteins were alpha-2-HS-glycoprotein (AHSG), complement C4-B, haptoglobin, C-reactive protein, and ceruloplasmin, whereas the down-regulation proteins were serum albumin, angiotensinogen, alpha-1-antichymotrypsin, Ig gamma-3 chain C region, fibrinogen gamma chain, apolipoprotein A-I, and Ig kappa chain C region. Among all the differentially expressed proteins, AHSG was validated by western blot and ELISA. The results were consistent with the data from 2D-DIGE, further suggesting that AHSG may be employed as a potential biomarker for the early diagnosis of HSCC. In summary, this study was the first to use 2D-DIGE and MALDI-TOF/TOF platform to identify the potential plasma biomarkers for HSCC. The plasma AHSG showed great potential for HSCC screening.

HMGB1 overexpression correlates with poor prognosis in early-stage squamous cervical cancer

High mobility group box 1 (HMGB1) is associated with tumor progression and a poor prognosis; microtubule-associated protein 1 light chain 3 (LC3) plays a critical role in autophagy. However, the roles of HMGB1 and LC3 in squamous cervical cancer (SCC) remain unclear. An array of 166 early-stage SCC, 62 cervical intraepithelial neoplasia (CIN), and 50 normal cervical tissue samples was assessed. HMGB1 and LC3 protein levels were examined by immunohistochemistry, and the associations of HMGB1 and LC3 levels with clinicopathological characteristics evaluated, to assess their prognosis significance. High nuclear HMGB1 levels were detected in 72.9% SCC cases; 16% cases showed cytoplasmic expression of HMGB1 in cancer cells with low nuclear expression. Interestingly, HMGB1 levels in SCC samples were significantly higher than CIN and control specimens, while lower LC3 expression was found in SCC samples (P < 0.001). Nuclear HMGB1 expression was weakly negatively correlated to LC3 amounts (r = -0.254, P = 0.001). High nuclear HMGB1 levels were associated with vascular metastasis (P < 0.05). In addition, cytoplasmic HMGB1 expression was associated with lymph node metastasis (P < 0.05). Furthermore, high nuclear HMGB1 levels and cytoplasmic HMGB1 expression predicted poor overall survival (OS) and disease-free survival (DFS). Meanwhile, high LC3 expression was associated with favorable prognosis. Multivariate analysis showed that both nuclear and cytoplasmic HMGB1 expressions were independent prognostic factors for overall- and disease-free survival, along with nodule metastasis. HMGB1 overexpression plays a significant role in SCC progression. Both nuclear and cytoplasmic HMGB1 are independent factors for poor prognosis in early-stage SCC.

Chloroquine-enhanced efficacy of cisplatin in the treatment of hypopharyngeal carcinoma in xenograft mice

Hypopharyngeal squamous cell carcinoma (HSCC) has the worst prognosis among head and neck cancers. Cisplatin (DDP)-based chemotherapy is an important part of multimodal treatments. However, resistance to DDP severely impairs the effectiveness of chemotherapy for HSCC. Chloroquine (CQ) has been reported to enhance the effectiveness of chemotherapy and radiotherapy in liver, pancreas, breast, prostate and colon tumors, but it is unclear whether CQ could increase the efficacy of DDP for treating HSCC. We inoculated BALB/c nude mice with a subcutaneous injection of human hypopharyngeal FaDu cells to generate our animal model. Mice were randomly divided into 4 groups and treated with vehicle control, CQ (60 mg/kg/day), DDP (5 mg/kg/6 days), or a combination of DDP and CQ. Tumor growth and survival of the mice were monitored. We found that CQ inhibited autophagy and increased DDP-induced apoptosis in the xenograft mouse model. CQ enhanced the efficacy of DDP, resulting in decreased tumor growth and prolonged survival of the mice. To test whether blocking autophagy enhanced the efficacy of DDP, FaDu cells were infected with lentiviral shRNA to Beclin-1 and inoculated into the flanks of nude mice. Inhibition of autophagy markedly enhanced the DDP-induced antitumor effect. Our study suggests that the addition of CQ to DDP-based chemotherapy could be a potential therapeutic strategy for treating HSCC, and the inhibition of autophagy may contribute to chemotherapy sensitization in HSCC.

Gene microarray analysis of lncRNA and mRNA expression profiles in patients with hypopharyngeal squamous cell carcinoma

BACKGROUND

Studies have shown that long noncoding RNAs (lncRNAs) are involved in the development and progression of many types of cancer. However, the mechanisms by which lncRNAs influence development and progression of hypopharyngeal squamous cell carcinoma (HSCC) are unclear.

METHOD

We investigated differences in lncRNA and mRNA expression profiles between 3 pairs of HSCC tissues and adjacent nontumor tissues by microarray analysis.

RESULTS

In HSCC tissues, 1299 lncRNAs were significantly upregulated (n=669) or downregulated (n=630) compared to levels in adjacent nontumor tissues. Moreover, 1432 mRNAs were significantly upregulated (n=684) or downregulated (n=748) in HSCC tissues. We randomly selected 2 differentially expressed lncRNAs (AB209630, AB019562) and 2 differentially expressed mRNAs (SPP1, TJP2) for confirmation of microarray results using qRT-PCR. The qRT-PCR results matched well with the microarray data. The differentially expressed lncRNAs and mRNAs were distributed on each of the chromosomes, including the X and Y chromosomes. Pathway analysis indicated that the biological functions of differentially expressed mRNAs were related to 48 cellular pathways that may be associated with HSCC development. GO analysis revealed that 593 mRNAs involved in biological processes, 50 mRNAs involved in cellular components, and 46 mRNAs involved in molecular functions were upregulated in the carcinomas; 280 mRNAs involved in biological processes, 58 mRNAs involved in cellular components, and 71 mRNAs involved in molecular functions were downregulated in the carcinomas. In addition, 8 enhancer-like lncRNAs and 21 intergenic lncRNAs with their adjacent mRNA pairs were identified as coregulated transcripts.

CONCLUSION

These findings provide insight into the mechanisms underlying HSCC tumorigenesis and will facilitate identification of new therapeutic targets and diagnostic biomarkers for this disease.

An autophagy-independent function for Beclin 1 in cancer

The involvement of Beclin 1 in cancer has been attributed primarily to its role in autophagy initiation. Our recent findings identify a novel, alternative mechanism by which Beclin 1 can impact tumor progression, through the regulation of growth factor receptor signaling.

Aberrant expression of PHLPP1 and PHLPP2 correlates with poor prognosis in patients with hypopharyngeal squamous cell carcinoma

The PHLPP (pleckstrin homology [PH] domain leucine rich repeat protein phosphatase) family, which represents a family of novel Ser/Thr protein phosphatases, is composed of 2 members: PHLPP1 and PHLPP2. PHLPPs partake in diverse cellular activities to exhibit their antitumor and metastasis suppressor functions. It is necessary to investigate the expression patterns of PHLPP1 and PHLPP2 in hypopharyngeal squamous cell carcinomas (HSCCs) and clarify their clinical significance. A total of 138 patients with primary HSCC who underwent curative surgical treatment as an initial treatment were enrolled in this study. A total of 138 HSCC specimens and 64 adjacent noncancerous mucosal epithelial tissues were collected. The expression levels of PHLPP1 and PHLPP2 were examined by quantitative reverse transcription polymerase chain reaction and immunohistochemistry assays. Correlations between clinicopathological parameters of the patients were further evaluated. PHLPP1 and PHLPP2 mRNA transcript levels were significantly lower in tumor samples than in paired adjacent nontumor mucosae (P<0.0001, both). Positive correlations were observed between the mRNA levels of PHLPP1 and PHLPP2 in HSCC tissues (correlation coefficient r = 0.678, P<0.001) and in adjacent nontumor mucosae (r = 0.460, P<0.001). The majority of the noncancerous tissues showed high expression levels of PHLPP1 (87.5%, 56/64) and PHLPP2 (85.9%, 55/64). However, the expressions of PHLPP1 and PHLPP2 were significantly decreased in 83.3% (115/138) and 82.6% (114/138) of tumor tissues, respectively (P<0.0001, both). The expressions of both PHLPP isoforms were significantly related to the tumor clinical stage, differentiation, and cervical lymph node metastasis (P<0.05, all). It was PHLPP1 but not PHLPP2 that was significantly related to the tumor T stage. Low PHLPP1 and PHLPP2 expressions were associated with poor overall survival (OS) in HSCC patients (P = 0.004, P = 0.008, respectively). Multivariate analysis revealed that PHLPP1 was an independent prognostic factor for OS. This study indicates that, in HSCC, aberrant expressions of PHLPP1 and PHLPP2 are common events, and loss of PHLPPs might identify patients with poor prognostic outcomes.