Regulatory role of the miR-142-3p/CDC25C axis in modulating autophagy in non-small cell lung cancer.

Background: With its diverse genetic foundation and heterogeneous nature, non-small cell lung cancer (NSCLC) needs a better comprehension of prognostic evaluation and efficient treatment targeting. Methods: Bioinformatics analysis was performed of The Cancer Genome Atlas (TCGA)-NSCLC and GSE68571 dataset. Overlapping differentially expressed genes (DEGs) were used for functional enrichment analysis and constructing the protein-protein interaction (PPI) network. In addition, key prognostic genes were identified through prognostic risk models, and their expression levels were verified. The phenotypic effects of cell division cycle 25C (CDC25C) regulation on NSCLC cell lines were assessed by in vitro experiments using various techniques such as flow cytometry, Transwell, and colony formation. Protein levels related to autophagy and apoptosis were assessed, specifically examining the impact of autophagy inhibition [3-methyladenine (3-MA)] and the miR-142-3p/CDC25C axis on this regulatory system. Results: CDC25C was identified as a key prognostic marker in NSCLC, showing high expression in tumor samples. In vitro experiments showed that CDC25C knockdown markedly reduced the capacity of cells to proliferate, migrate, invade, trigger apoptosis, and initiate cell cycle arrest. CDC25C and miR-142-3p displayed a reciprocal regulatory relationship. CDC25C reversed the inhibitory impacts of miR-142-3p on NSCLC cell cycle proliferation and progression. The synergy of miR-142-3p inhibition, CDC25C silencing, and 3-MA treatment was shown to regulate NSCLC cell processes including proliferation, apoptosis, and autophagy. Conclusions: MiR-142-3p emerged as a key player in governing autophagy and apoptosis by directly targeting CDC25C expression. This emphasizes the pivotal role of the miR-142-3p/CDC25C axis as a critical regulatory pathway in NSCLC.

Ghost cell odontogenic carcinoma: A rare case report and review of literature.

RATIONALE: Ghost cell odontogenic carcinoma is a rare malignant odontogenic carcinoma characterized by the presence of ghost cells. It has a nonspecific clinical and radiographic presentation and can be locally destructive and invasive, sometimes with distant metastases. However, no effective systemic therapy is currently recommended for such patients. PATIENT CONCERNS: The patient has been unable to undergo surgery or radiotherapy again. Therefore, he was referred to our department for a more aggressive, multimodal systematic treatment program. DIAGNOSES: The histopathological examination was morphologically suggestive of ghost cell odontogenic carcinomas. INTERVENTIONS: We report a case of locally invasive primary inoperable odontogenic shadow cell carcinoma in a 31-year-old Chinese man who achieved treatment with Toripalimab and chemotherapy, followed by Toripalimab maintenance therapy after 6 cycles. OUTCOMES: He achieved partial remission after treatment. The quality of life significantly improved after treatment. There were no grade 3/4 treatment-related adverse events during treatment. LESSONS: This case presented that Toripalimab and chemotherapy may be a safe and effective systemic therapy for ghost cell odontogenic carcinoma.

A nomogram prediction of citrate reaction during mononuclear cell collection in solid tumor patients.

PURPOSE: Citrate reaction is one of the main adverse events in peripheral blood mononuclear cell (MNC) collection. The aim of this study was to elucidate the risk factors for citrate reaction in patients with advanced solid tumor collection and to construct a nomogram to predict the risk. METHODS: One hundred forty-eight patients with advanced solid tumor who underwent peripheral blood MNC collection in our hospital between January 2021 to December 2021 were selected. The general data, creatinine level before collection, Ca2+ concentration before collection, absolute value of monocyte lymphocytes before collection, circulating blood volume, anticoagulant dosage, and blood collection duration were included in Logistic regression analysis to identify the risk factors of citrate reaction. According to the results of the multivariate logistic model, nomogram was established and receiver operating characteristic (ROC) curve was drawn to evaluate the predictive value of the model. RESULTS: Among the 148 solid tumor patients, 35 patients (23.6%) of the 148 patients developed citrate reaction. Multivariate analysis showed that the risk factors for citrate reaction in the process of collection included sex (odds ratio [OR] = 6.718; 95% confidence interval [95% CI]: 2.191-20.594, P = .001), age (OR = 0.957; 95% CI: 0.921-0.996, P = .03), and processed circulating blood volume (OR = 1.001; 95% CI: 1.000-1.002, P = .01). Logistic regression can analyze independent risk factors and establish risk prediction model. The predictive performance of the model is good, and the area under ROC curve is 0.799. CONCLUSIONS: The MNC collection process is safe. The incidence of citrate reaction in the collection of peripheral blood MNCs from patients with advanced solid tumor is related to the age, gender, and processed circulating blood volume of patients. The nomogram can be used to assess a patient's risk of citrate reaction.

Machine learning based tissue analysis reveals Brachyury has a diagnosis value in breast cancer.

BACKGROUND: The aim of the present study was to confirm the role of Brachyury in breast cancer and to verify whether four types of machine learning models can use Brachyury expression to predict the survival of patients. METHODS: We conducted a retrospective review of the medical records to obtain patient information, and made the patient's paraffin tissue into tissue chips for staining analysis. We selected 303 patients for research and implemented four machine learning algorithms, including multivariate logistic regression model, decision tree, artificial neural network and random forest, and compared the results of these models with each other. Area under the receiver operating characteristic (ROC) curve (AUC) was used to compare the results. RESULTS: The chi-square test results of relevant data suggested that the expression of Brachyury protein in cancer tissues was significantly higher than that in paracancerous tissues (P=0.0335); patients with breast cancer with high Brachyury expression had a worse overall survival (OS) compared with patients with low Brachyury expression. We also found that Brachyury expression was associated with ER expression (P=0.0489). Subsequently, we used four machine learning models to verify the relationship between Brachyury expression and the survival of patients with breast cancer. The results showed that the decision tree model had the best performance (AUC = 0.781). CONCLUSIONS: Brachyury is highly expressed in breast cancer and indicates that patients had a poor prognosis. Compared with conventional statistical methods, decision tree model shows superior performance in predicting the survival status of patients with breast cancer.

Patients with radiation enteritis present regulatory T cell impairment associated with CTLA-4.

Radiation enteritis is one of the most common side effects of ionizing radiation in patients with pelvic cancers. Increasing amounts of evidence indicate that pro-inflammatory responses significantly contribute to the development of radiation enteritis. In this study, we investigated the association between T regulatory (Treg) cells and the risk of developing radiation enteritis in cervical cancer patients. The following observations were made. First, the frequencies of CD25hiFoxp3+ Treg cells were significantly lower in patients with radiation enteritis than in both healthy subjects and cervical cancer patients without radiation enteritis. Also, patients with the more severe grade 3 enteritis presented significantly lower Treg levels than patients with the more common grade 1 enteritis. Second, the expression of several molecules associated with Treg function, including CTLA-4, IL-10, TGF-ß, and perforin, was significantly lower in patients with radiation enteritis than in healthy subjects. In patients without radiation enteritis, however, only CTLA-4, but not other Treg-associated suppressive molecules, was reduced in Treg cells. Third, Treg cells can markedly suppress CD8 T cell proliferation, but in patients with radiation enteritis, this function of Treg cells was significantly impaired, in a manner that was associated with lower CTLA-4 expression. Overall, these data suggest that the frequency and function of Treg cells is negatively associated with the risk of developing enteritis following radiation. In clinical practice, the characteristics of Treg cells may be considered to evaluate the risk of developing enteritis if the cancer patient is receiving ionizing radiation.

Characterization of intratumoral and circulating IL-10-producing B cells in gastric cancer.

The tumor microenvironment harbors multiple immunosuppressive mechanisms, many of which involve suppressive immune cells. B regulatory (Breg) cells, as critical regulators of immune responses, were investigated in patients with gastric carcinoma. In the present study, the B cells that expressed IL-10 were highly enriched in tumor-infiltrating B cells, and could also be found at reduced frequencies in circulating B cells. These cells expressed high CD19 and CD20, and were almost exclusively CD27+CD10-. The IL-10 expression was significantly higher in CD27+CD10--sorted B cells than in CD27-CD10--sorted B cells. In an in vitro coculture of B cells and autologous T cells, CD27+CD10- B cells were capable of reducing the levels of CD4 T cell-mediated IFNγ, TNF, and IL-17 expression and the levels of CD8 T cell-mediated IFNγ and TNF expression. These regulatory effects were dependent on IL-10 as well as CD80/CD86. Interestingly, CD27+CD10- B cells also significantly elevated IL-10 production from CD4 and CD8 T cells in an IL-10-dependent manner. Overall, we here report enrichment of IL-10-expressing CD27+CD10- B cells in the intratumoral environment, which could significantly alter the cytokine production profile by CD4 and CD8 T cells.

Gastric cancer patients display a distinctive population of IFNg+IL10+ double positive CD8 T cells, which persists longer during prolonged activation.

IL10 is generally regarded as a broad-spectrum regulatory cytokine. However, the role of IL10 in CD8 T cells remains controversial. In this study, we investigated the characteristics of endogenous IL10 by CD8 T cells in gastric cancer (GC) patients. Using intracellular staining, we found that in both GC patients and healthy controls, the majority of IL10-expressing CD8 T cells also presented concurrent IFNg expression. Interestingly, the frequency of IFNg+IL10+ CD8 T cells was significantly higher in GC patients than in healthy controls, while the frequency of IFNg+IL10- CD8 T cells was significantly lower in GC patients than in healthy controls. Compared to the IFNg-IL10- CD8 T cells, both IFNg+IL10- and IFNg+IL10+ CD8 T cells presented significantly higher expression of activation/inhibitory markers. Interestingly, the IFNg+IL10+ cells presented lower PD1 and TIM3 and higher KLRG1 than the IFNg+IL10- CD8 T cells. Remarkably, the IFNg+IL10+ CD8 T cells, but not the IFNg+IL10- CD8 T cells, were highly enriched in the CD45RO+CXCR5+ subset. Prolonged activation resulted in significant enrichment of IFNg+IL10+ CD8 T cells over time. Interestingly, compared to the CD45RO+CXCR5- CD8 T cells, the CD45RO+CXCR5+ CD8 T cells presented stronger proliferation capacity at later stages of stimulation, and higher viability throughout the stimulation process. Overall, our investigation demonstrated that GC patients were enriched with a distinctive population of IFNg+IL10+ double positive CD8 T cells, which resembled T follicular cytotoxic cells and could persist longer during prolonged activation.

Proline-Rich Protein 11 Regulates Self-Renewal and Tumorigenicity of Gastric Cancer Stem Cells.

BACKGROUND/AIMS: Gastric cancer is a highly aggressive tumor containing cancer stem cells (CSCs), which participate in tumor initiation, therapeutic resistance, and tumor relapse. Proline-rich protein 11 (PRR11) has been shown to be up-regulated in human cancers; however, its role in gastric CSCs is unknown. We hypothesize that PRR11 may affect tumorigenicity of gastric CSCs. In this study, we explored the biological function and regulation of PRR11 in gastric CSCs. METHODS: Expression of PRR11 was evaluated in gastric CSC cell line by real-time quantitative PCR and western blot. The effect of PRR11 on tumorigenicity was examined by interference with gene expression using lentiviral vector-loaded shRNA. A xenograft tumor model using NOD/SCID mice was established to examine the role of PRR11 in tumor development. RESULTS: Data showed that PRR11 was highly expressed in gastric CSCs. PRR11 was responsible for the maintenance of self-renewal and tumorigenicity of gastric CSCs, and overexpression of exogenous PRR11 could restore the self-renewal of gastric non-CSCs. Furthermore, interference with PRR11 altered the expression of stemness transcription factors. Interestingly, MAPK signaling controlled PRR11 expression by increasing PRR11 protein stability, and maintained gastric CSCs self-renewal in a PRR11 dependent manner. CONCLUSIONS: PRR11 regulated self-renewal and tumorigenicity of gastric CSCs through MAPK signaling, and could be used as a therapeutic target for gastric cancer.

Tr1 responses are elevated in asymptomatic H. pylori-infected individuals and are functionally impaired in H. pylori-gastric cancer patients.

Gastric cancer is one of the most lethal malignancies worldwide. Chronic Helicobacter pylori (H. pylori) infection can induce an inflammatory response that promotes atrophic gastritis, a preceding event to cancer development. The type 1 regulatory T (Tr1) cells have recently emerged as a critical participant in maintaining self-tolerance. In this study, we examined Tr1 cells in H. pylori infection and gastric cancer development. While H. pylori-uninfected (uninfected) subjects presented low Tr1 frequency in the peripheral blood, H. pylori-infected asymptomatic (infected) individuals and H. pylori-infected gastric cancer (cancer) individuals both presented elevated Tr1 frequency. Although the Tr1 cells from infected asymptomatic subjects were functionally more potent than those from uninfected healthy subjects, the Tr1 cells in cancer individuals demonstrated several functional impairments, such as reduced interleukin 10 (IL-10) expression, lower secretion of cytolytic factors including granzyme B and perforin, and lower capacity to suppress CD4+CD25- T cell and CD8+ T cell proliferation. In addition, the frequency and function of Tr1 cells were positively correlated with the disease-free survival of the gastric cancer patients. These results suggest that Tr1 cells might be involved in the regulating immune responses in H. pylori infection and gastric cancer development. The fact that Tr1 cells could suppress inflammation and produce cytotoxic molecules at the same time has made them attractive potential candidates for future immunotherapies.

Circulating regulatory Tfh cells are enriched in patients with chronic hepatitis B infection and induce the differentiation of regulatory B cells.

Chronic hepatitis B virus (HBV) infection is a complex disease with dysregulations in the immune system. Follicular helper T (Tfh) cells are professional B helper cells that are crucial to the development of antibody responses and are involved in a variety of diseases. In this study, we examined the circulating Tfh cells in patients with chronic HBV infection. We observed that CD3+CD4+CXCR5+ circulating Tfh cells contained a CD25+Foxp3+ Treg-like subset that was significantly enriched in patients with chronic HBV infections. The CD25+ Tfh subset presented distinctive cytokine secretion profile, such as lower interferon (IFN)-γ and interleukin (IL)-17, and higher transforming growth factor (TGF)-ß secretion, compared to the CD25- Tfh subset. When incubated with autologous naive CD10-CD27-CD19+ B cells, the CD25+ Tfh subset was less capable of mediating CD20-/loCD38+ plasmablast differentiation than the CD25- Tfh subset. In terms of Ig production, CD25+ Tfh cells were more potent at inducing IgM but less potent at inducing IgG and IgA than CD25- Tfh cells. Interestingly, B cells following incubation with CD25+ Tfh cells presented elevated regulatory function, with higher production of IL-10 and enhanced capacity of suppressing autologous CD8+ T cell inflammation. In the chronic HBV-infected patients, the frequency of IL-10+ B cells and the HBV viral load were positively correlated with the frequency of CD25+Foxp3+ CD4+CXCR5+ Tfh cells. Together, this study presented that CD25+Foxp3+ Treg-like Tfh cells were enriched in chronic HBV-infected patients and could promote regulatory B cell functions.

Proinflammatory follicular helper T cells promote immunoglobulin G secretion, suppress regulatory B cell development, and correlate with worse clinical outcomes in gastric cancer.

Gastric cancer is one of the most common and aggressive malignancies. Both bacterial virulence factors and host chronic inflammation are thought to promote gastric cancer development. In this study, we investigated the potential involvement of follicular helper T cells in gastric cancer. Functions of follicular helper T subsets were examined in Helicobacter pylori-infected gastric cancer patients and H. pylori-infected but asymptomatic individuals. We found that the follicular helper T cells in gastric cancer individuals were skewed toward the Th1 and Th17 subsets compared to those in H. pylori-infected but asymptomatic individuals. In a naive B cell-follicular helper T cell coculture, the Th1-follicular helper T cells by themselves were ineffective at stimulating a robust antibody response, unlike the Th2-follicular helper T and Th17-follicular helper T cells. However, Th1-follicular helper T cells significantly promoted the immunoglobulin G response in collaboration with other follicular helper T subsets, through the secretion of interferon gamma. We also found that Th1-follicular helper T cells suppressed the development of interleukin-10+ regulatory B cells, a cell type previously thought to protect H. pylori-infected individuals from tissue damage. In addition, the frequency of Th1-follicular helper T cells in gastric cancer patients was negatively correlated with the disease-free survival of gastric cancer patients after tumor resection. These results suggested that dysregulation of follicular helper T subsets in gastric cancer patients, characterized by increased Th1-follicular helper T cells, contributed to inflammation and tumor development.

Stimulatory role of interleukin 10 in CD8+ T cells through STATs in gastric cancer.

CD8+ T cells are considered to be critical in tumor surveillance and elimination. Increased CD8+ T cell frequency and function is associated with better prognosis in cancer patients. Interleukin 10 is a cytokine with controversial roles in CD8+ T cell-mediated anti-tumor immunity. We therefore examined the interleukin 10 expression and consumption in CD8+ T cells harvested from the peripheral blood and resected tumors of gastric cancer patients of stages II-IV. We found that the gastric cancer patients presented significantly elevated frequencies of interleukin 10-expressing cells in both CD4+ and CD8+ T cells compared to healthy controls. But distinctive from the interleukin 10-expressing CD4+ T cells, which increased in frequency in advanced cancer, the interleukin 10-expressing CD8+ T cells did not increase with cancer stage in the peripheral blood and actually decreased with cancer stage in resected tumor. Interleukin 10 and interleukin 10 receptor expression was also enriched in interferon gamma-expressing activated CD8+ T cells. Compared to interleukin 10-nonexpressing CD8+ T cells, interleukin 10 receptor-expressing CD8+ T cells secreted significantly elevated interferon gamma levels. Treatment of anti-CD3/CD28-stimulated, purified CD8+ T cells with interleukin 10 alone could significantly enhance CD8+ T cell survival, an effect dependent on interleukin 10 receptor expression. Interleukin 10 also increased CD8+ T cell proliferation synergistically with interferon gamma but not alone. Analysis of downstream signal transducer and activator of transcription molecules showed that interleukin 10 treatment significantly increased the phosphorylation of signal transducer and activator of transcription 3 and signal transducer and activator of transcription 1 to lesser extent. Together, these results demonstrate that interleukin 10 possessed stimulatory roles in activated CD8+ T cells from gastric cancer patients.

Cytotoxic CD4+ T cells are correlated with better prognosis in Han Chinese grade II and grade III glioma subjects and are suppressed by PD-1 signaling.

PURPOSE: Malignant gliomas are the most common tumors in the central nervous system with a poor prognosis. Recently, CD4+ cytotoxic T cells (CTLs) are being increasingly recognized as possessing antitumor capacity. However, their presence, activity and regulation in glioma have not been investigated in detail. METHODS: To examine this, 72 grade II and grade III Han Chinese glioma patients and 30 Han Chinese healthy controls were investigated. RESULTS: We found that compared to healthy controls, glioma patients had significantly upregulated frequencies of circulating CD4+ CTLs, identified by the expression of granzyme A (GzmA), granzyme B (GzmB) and/or perforin. The stimulated CD4+ CTLs in grade II and grade III glioma patients also had less proliferative ability than those in healthy controls, a feature of suppression that progressed with tumor grade. The frequencies of GzmB-expressing circulating CD4+ CTLs were directly associated with prognosis. We hypothesized that the programed death 1 (PD-1)/PD-ligand 1 (L1) interaction possibly contributed to the suppression of CD4+ CTLs in grade II and grade III glioma, since an upregulation of PD-1 was observed on CD4+ CTLs in glioma compared to those in the healthy individuals. Blockade of the PD-1/PD-L1 interaction with neutralizing antibodies significantly increased the proliferation and granzyme or perforin production by CD4+ CTLs in grade II and grade III glioma patients. CONCLUSIONS: These data suggest that the CD4+ CTLs in grade II and grade III glioma patients contribute to antitumor immunity and could be suppressed by PD-1 signal transduction.

Preferential Tim-3 expression on Treg and CD8(+) T cells, supported by tumor-associated macrophages, is associated with worse prognosis in gastric cancer.

While infection with H. pylori is a strong risk factor for gastric cancer, most H. pylori-colonized individuals, even those with the high-risk CagA(+)VacA(+) strain, remain asymptomatic over their lifetime. We hypothesized that the discordant outcomes were due to differences in the host immune responses. Previously, Tim-3-mediated immune modulation was observed in H. pylori-challenged mice. In this study, we compared Tim-3-related responses in CagA(+)VacA(+) H. pylori-infected asymptomatic individuals and H. pylori-associated gastric adenocarcinoma patients. We showed that compared to H. pylori-uninfected individuals, both H. pylori-infected asymptomatic and gastric cancer patients upregulated Tim-3 overall. However, the Tim-3 upregulation was enriched on Th1 cells in asymptomatic patients and on Treg and CD8(+) T cells in gastric cancer patients, with respective differences in T cell subset functions. In gastric cancer patients, high Tim-3 expression on Treg and CD8(+) T cells, but not on Th1 cells, was associated with worse prognosis. H. pylori-antigen presentation by tumor-associated macrophages upregulated Tim-3 expression more effectively than by blood monocyte-derived macrophages in vitro. The upregulation of Tim-3 in vitro depended on the concentration of H. pylori antigen but not on whether the cells were from asymptomatic or cancer patients. These data suggest that the discrepancy in Tim-3 upregulation in asymptomatic and cancer subjects is induced by cancer but not the other way around. Once gastric cancer is developed, Tim-3 expression is associated with worse prognosis.

PRR11 Is a Prognostic Marker and Potential Oncogene in Patients with Gastric Cancer.

PRR11 is a potential candidate oncogene that has been implicated in the pathogenesis of lung cancer, however the role of PRR11 in gastric cancer is currently unclear. In the present study, we investigated the role of PRR11 in gastric cancer by evaluating its expression status in samples from a cohort of 216 patients with gastric cancer. PRR11 was found to be overexpressed in 107 (49.5%) patients by immunohistochemistry of tissue microarrays generated using the patient samples. Furthermore, PRR11 overexpression was found to correlate significantly with clinicopathologic features such as tumor invasion, tumor differentiation, and disease stage. Survival analysis of the cohort revealed that PRR11 is an independent prognostic factor for gastric cancer patients. PRR11 was stably silenced in a gastric carcinoma cell line using an shRNA-based approach, and treated cells showed decreased cellular proliferation and colony formation in vitro and cell growth in vivo, companied by decreased expression of CTHRC1 and increased expression of LXN, proteins involved in tumor progression. Evaluation of human gastric cancer samples demonstrated that PRR11 expression was also associated with increased CTHRC1 and decreased LXN expression. These data indicate that PRR11 may be widely activated in human gastric cancer and are consistent with the hypothesis that PRR11 functions as an oncogene in the development and progression of gastric cancer.

Regulatory B Cell Function Is Suppressed by Smoking and Obesity in H. pylori-Infected Subjects and Is Correlated with Elevated Risk of Gastric Cancer.

Helicobacter pylori infection occurs in more than half of the world's population and is the main cause for gastric cancer. A series of lifestyle and nutritional factors, such as tobacco smoking and obesity, have been found to elevate the risk for cancer development. In this study, we sought to determine the immunological aspects during H. pylori infection and gastric cancer development. We found that B cells from H. pylori-infected patients presented altered composition and function compared to uninfected patients. IL-10-expressing CD24+CD38+ B cells were upregulated in H. pylori-infected patients, contained potent regulatory activity in inhibiting T cell pro-inflammatory cytokine secretion, and responded directly to H. pylori antigen stimulation. Interestingly, in H. pylori-infected smoking subjects and obese subjects, the number of IL-10+ B cells and CD24+CD38+ B cells were reduced compared to H. pylori-infected asymptomatic subjects. Regulatory functions mediated by CD24+CD38+ B cells were also impaired. In addition, gastric cancer positive patients had reduced IL-10-producing B cell frequencies after H. pylori-stimulation. Altogether, these data suggest that in H. pylori-infection, CD24+CD38+ B cell is upregulated and plays a role in suppressing pro-inflammatory responses, possibly through IL-10 production, a feature that was not observed in smoking and obese patients.

Elevated expression of immunity-related GTPase family M in gastric cancer.

Recent researches have suggested that autophagy may play critical roles in tumorigenesis. Immunity-related GTPase family M (IRGM) is a human protein highlighted for its contribution to autophagy upon inflammation and infections. Studies have shown that IRGM is involved in the development of several cancers. In the current study, we investigated expression of IRGM and gastric cancer. Levels of messenger RNA (mRNA) and protein were examined by real-time reverse transcription PCR (RT-PCR) and Western blot, respectively. Data showed that mRNA level of IRGM was significantly increased in peripheral blood mononuclear cells (PBMCs) of gastric cancer patients than in PBMCs from healthy controls (p > 0.05). Moreover, both mRNA and protein levels were significantly higher in cancer tissues compared to adjacent noncancerous stomach tissues (1.28-fold, p < 0.001; 1.19-fold, p < 0.01, respectively). However, the level of IRGM seemed not to be affected by Helicobacter pylori infection. In addition, we investigated the correlation between IRGM expression and cancer stages and identified that stage IV patients had upregulated mRNA level and protein level of IRGM in cancer tissues than those stage I patients. Our findings suggest that expression of IRGM is dysregulated in gastric cancer and that the molecule may affect progression of the disease.

ABCG2 regulates the pattern of self-renewing divisions in cisplatin-resistant non-small cell lung cancer cell lines.

Overexpression of ABCG2 is considered a major mechanism of cancer drug resistance. Recent studies have shown that ABCG2 can regulate the switch between symmetric and asymmetric cell division in adult stem cells; however, the relationship between ABCG2 and cell division in drug-resistant cancer cells remains to be determined. In the present study, we demonstrated that ABCG2 is involved in the cell division of drug-resistant cancer cells. We first established drug-resistant H460 and A549 cell lines by repeated exposure to cisplatin and found that the expression of ABCG2 in these cell lines was significantly increased. As evidenced by PKH-26 staining, these drug-resistant cell lines favored symmetric division, which differed from the asymmetric division of the parental cells. Furthermore, we established stable ABCG2­overexpressing and stable shRNA-ABCG2­knockdown cell lines to evaluate the potential role of ABCG2 in cancer cell division. The results showed that overexpression of ABCG2 in A549 parental cells significantly increased the proportion of symmetric division, whereas knockdown of ABCG2 in drug-resistant A549 cells significantly increased the proportion of asymmetric division. Taken together, our findings suggest that ABCG2 is involved in the modulation of cancer drug resistance by regulating the pattern of cell division. The present study provides novel insight into the role of ABCG2 in cancer treatment resistance.

EtBr-induced selective degradation of mitochondria occurs via autophagy.

Recent studies have implicated autophagy in numerous cellular responses to stress. During the establishment of human lung cancer cell lines without mitochondrial DNA, a significant depopulation of mitochondria occurred that was accompanied by the loss of the mitochondrial membrane potential. Notably, we observed autophagy in ethidium bromide (EtBr)-induced mitochondrial degradation. In the present study, we confirmed the involvement of autophagy in mitochondrial degradation after exposure to a low concentration of EtBr. Lung cancer cells undergoing mitochondrial autophagy exhibited a slower growth rate in vitro and in vivo. Furthermore, the degradation was mediated by the class III phosphatidylinositol 3-kinase (PI3K)-Beclin-1 complex. These findings indicate that autophagy is responsible for EtBr­induced mitochondrial degradation via the PI3K­Beclin-1 signaling pathway.

Human mesenchymal stem cells enhance autophagy of lung carcinoma cells against apoptosis during serum deprivation.

Currently, some evidence suggests that human multipotential mesenchymal stems cells (hMSCs) aid tumor growth and metastasis. Nutrient deprivation and oxygen deficiency are representative characteristics of solid tumor microenvironment during the cancer development. Because the effects of hMSCs on tumors under stressful conditions have not been determined, we investigated the survival mechanisms used by stressed stromal cells on A549 and SPC-1 lung carcinoma cell lines in vitro and in vivo. An indirect culture system was used to investigate the effects of hMSCs on viability and apoptosis in starved carcinoma cells and focused on the role of autophagy in regulating the survival of carcinoma cells. The results showed that A549 and SPC-1 cells had higher viability when co-cultured with hMSCs and that this was mainly attributed to decreased apoptosis. Autophagosomes were analyzed using GFP-LC3 and electron microscopy, which showed that autophagy was significantly activated in the starved co-culture groups. However, the inhibition of autophagy by the autophagic inhibitor 3-MA significantly abrogated the apoptosis reduction in either single groups or co-culture groups under serum deprivation, which implied that the hMSCs protected against apoptosis by enhancing autophagy in lung carcinoma cells in vitro. We also observed that hMSCs promoted tumor initiation and growth in vivo. In conclusion, our study demonstrates that hMSCs can protect carcinoma cells from nutrient deprivation-induced apoptosis and promote tumor initiation and growth, and, interestingly, autophagy plays an important role in the survival of cancer cells.