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.

shRNA targeting Bmi1 impedes the self-renewal of cisplatin-enriched stem-like cells in human A549 cells.

It has been hypothesized that cancer stem-like cells are responsible for tumor recurrence following chemotherapy. Evidence on the mechanisms through which drug-resistant stem-like cells recapitulate the tumor mass has not been definitively reported. Based on this information, we investigated the enrichment ability of a population of stem-like cells following treatment with cisplatin in human A549 cells and focused on the molecular mechanisms regulating the self-renewal of stem-like cells. A population of stem-like cells was enriched following cisplatin treatment and was defined phenotypically and functionally based on the expression of certain stem cell markers, sphere-forming ability, multipotent differentiation and induction of xenograft tumors in vivo. For various types of differentiated cells, Bmi1 has been reported to be important for cell proliferation and for the self-renewal of stem cells. The high expression of Bmi1 in cisplatin-enriched stem-like cells was shown using Q-PCR and western blotting; therefore, the role of Bmi1 was investigated in cisplatin-enriched stem-like cells by infecting cisplatin-enriched stem-like cells with Bmi1-targeted RNAi lentiviruses. Cell proliferation, tumor sphere formation and xenograft formation was reduced following knockdown of Bmi1. Based on our results, we propose that, after cisplatin treatment, Bmi1 is required for the self-renewal of stem-like cells that are important for the expansion of the stem-like cell pool in human A549 cells and that targeting Bmi1 slows down the formation of tumors in vivo.

[Evaluation of gefitinib plus radiotherapy in non-small-cell lung cancer patients with brain metastases].

OBJECTIVE: To evaluate the efficacies of gefitinib plus radiotherapy in the treatment of brain metastases in non-small-cell lung carcinoma (NSCLC) patients. METHODS: A retrospective analysis was conducted for 161 NSCLC patients with brain metastases treated in Xinqiao Hospital from January 2001 to January 2010. And 38 patients aged 38 - 77 years old received the combined regimen of gefitinib plus radiotherapy. It consisted of synchronically practicing general or stereotactic brain radiotherapy and an oral intake of gefitinib (250 mg, QD for at least 8 consecutive weeks). The efficacies and toxicity were evaluated at Week 12 after the initial treatment. A total of 123 patients aged 37 - 76 years old undergoing whole brain or stereotactic radiotherapy were used as control. χ(2) test between two groups was carried out to evaluate the objective response rate (ORR), disease control rate (DCR), brain metastasis related symptoms and III-IV degree of toxicity. Non-parametric rank tests were performed to compare the U.S. Eastern Cooperative Oncology Group (ECOG) performance status score between two groups. RESULTS: In the combination therapy group, the levels of ORR and DCR were significantly higher than those in the conventional treatment group (31.6%, 78.9% vs 15.4%, 60.2%). The differences were statistically significant (χ(2) = 4.859, P = 0.027 and χ(2) = 4.479, P = 0.034); significant difference existed in brain metastasis-related symptoms between two groups (χ(2) = 4.612, P = 0.037); the ECOG scores were evaluated in the combination therapy group. And they were as follows: 0 - 1 (n = 18), 2 (n = 11), 3 - 4 (n = 9) at pre-treatment vs 0 - 1 (n = 27), 2 (n = 6), 3 - 4 (n = 5) at post-treatment. The ECOG score significantly improved after treatment (Z = -2.012, P = 0.044). Regarding the III-IV degree of toxicity, the combination therapy group had 4 patients with acne-like rash and it was significantly higher than that in the conventional therapy group (n = 0) (P = 0.003). But no difference existed in the occurrence of fatigue, nausea, vomiting, diarrhea and myelosuppression. CONCLUSION: The combined regimen of gefitinib plus radiotherapy can improve the therapeutic efficacies of brain metastases and enhance the quality-of-life in NSCLC patients, side effects are tolerable.

Establishing a lung cancer stem cell culture using autologous intratumoral fibroblasts as feeder cells.

Human LCSCs (lung cancer stem cells) were first isolated from lung cancer patients and cultured using serum-free culture methods. To recreate the intratumoural microenvironment to sustain LCSC growth, autologous intratumoral fibroblasts were used as feeder cells. In this study, we investigated the growth and maintenance of pluripotency in prolonged LCSCs culture on autologous intratumoural fibroblasts. LCSCs isolated from three clinical samples all showed vigorous growth on feeder cells for 16 weeks of continuous cultures with a doubling time of 41-47 h. The cells continued expressing stem cell marker CD133 and remained undifferentiated. Pluripotency was demonstrated by tumour formation in immunodeficient mice. In a feeder-free culture system, growth of LCSCs spheres was retarded and would cease when the diameter reached 100 µm if immediate passage was not performed. Moreover, spontaneous differentiation was more frequently seen in a serum-free culture system. In conclusion, we have successfully established a culture system using autologous intratumoural fibroblast cells as feeder cells for prolonged culture of undifferentiated LCSCs in vitro.

Effects of berberine against radiation-induced intestinal injury in mice.

PURPOSE: Radiation-induced intestinal injury is a significant clinical problem in patients undergoing abdominal radiotherapy (RT). Berberine has been used as an antimicrobial, anti-inflammatory, and antimotility agent. The present study investigated the protective effect of berberine against radiation-induced intestinal injury. METHODS AND MATERIALS: The mice were administrated berberine or distilled water. A total of 144 mice underwent 0, 3, 6, 12, or 16 Gy single session whole-abdominal RT and 16 mice underwent 3 Gy/fraction/d for four fractions of fractionated abdominal RT. Tumor necrosis factor-alpha, interleukin-10, diamine oxidase, intestinal fatty acid-binding protein, malonaldehyde, and apoptosis were assayed in the mice after RT. The body weight and food intake of the mice receiving fractionated RT were recorded. Another 72 mice who had undergone 12, 16, or 20 Gy abdominal RT were monitored for mortality every 12 h. RESULTS: The body weight and food intake of the mice administered with distilled water decreased significantly compared with before RT. After the same dose of abdominal RT, tumor necrosis factor-alpha, diamine oxidase, intestinal fatty acid-binding protein in plasma and malonaldehyde and apoptosis of the intestine were significantly greater in the control group than in the mice administered berberine (p < .05-.01). In contrast, interleukin-10 in the mice with berberine treatment was significantly greater than in the control group (p < .01). A similar result was found in the fractionated RT experiment and at different points after 16 Gy abdominal RT (p < .05-.01). Berberine treatment significantly delayed the point of death after 20 Gy, but not 16 Gy, abdominal RT (p < .01). CONCLUSION: Treatment with berberine can delay mortality and attenuated intestinal injury in mice undergoing whole abdominal RT. These findings could provide a useful therapeutic strategy for radiation-induced intestinal injury.

Berberine inhibits acute radiation intestinal syndrome in human with abdomen radiotherapy.

Radiation-induced acute intestinal symptoms (RIAISs) are the most relevant complication of abdominal or pelvic radiation. Considering the negative impact of RIAIS on patients' daily activities, the preventive effects of berberine on RIAIS in patients were investigated. Thirty-six patients with seminoma or lymphomas were randomized to receive berberine oral (n = 18) or not (n = 18). Forty-two patients with cervical cancer were randomized to a trial group (n = 21) and control group (n = 21). Radiotherapy used a parallel opposed anterior and posterior. 300-mg berberine was administered orally three times daily in trial groups. Eight patients with RIAIS were treated with 300-mg berberine three times daily from the third to the fifth week. Toxicities, such as fatigue, anorexia/nausea, etc., were graded weekly according to CTC version 2.0. Patients with abdominal/pelvic radiation in the control group showed grade 1 fatigue, anorexia/nausea, colitis, vomiting, proctitis, weight loss, diarrhea and grade 2 anorexia/nausea, fatigue. Only grade 1 colitis, anorexia/nausea, and fatigue were seen in patients of abdominal radiation treated with berberine. Grade 1 fatigue, colitis, anorexia/nausea, and proctitis occurred in patients of pelvic radiotherapy treated with berberine. Pretreatment with berberine significantly decreased the incidence and severity of RIAIS in patients with abdominal/pelvic radiotherapy when compared with the patients of the control group (P < 0.05). RIAIS were reduced in patients with abdominal radiotherapy/pelvic radiation after receiving berberine treatment. Berberine significantly reduced the incidence and severity of RIAIS and postponed the occurrence of RIAIS in patients with abdominal or whole pelvic radiation.

Lung cancer stem cells research. Clues from ontogeny.

Cancer stem cell (CSC) hypothesis provides us with a new approach to the understanding of carcinogenesis, therapeutics, and prevention strategies. In recent years, the origin and biological characteristics of CSC were widely studied in solid tumors; it is astonishing to find out the delicate relevancy between CSC and committed progenitors evolved from embryonic stem cells (ESC) during organ development. In this review, we propose that some key molecular signal pathways during lung development are crucial for abnormal self-renewal and differentiation of lung cancer stem cell as well as try to elaborate the lung CSCs from the point view of ontogeny.

Inhibition of tumor growth and metastasis by non-small cell lung cancer cells transfected with cyclin D1-targeted siRNA.

To observe whether cyclin D1 siRNA-mediated inhibition of cyclin D1 represents a promising antigrowth and antimetastatic strategy for cancer gene therapy, particularly for non-small cell lung cancers. To stably transfect the A549 cell line with a cyclin D1-targeted siRNA to downregulate cyclin D1 expression and observe the effects on protein expression, and tumor growth in vitro and in vivo. Expression of cyclin D1-targeted siRNA resulted in a decrease in cyclin D1, MMP-2, RhoA, and Rac1 protein levels, as detected by Western blot and immunofluorescence studies. Transfected cells also exhibited a marked decrease in the rate of cell growth, and decreased invasive capacity, compared to cells transduced with a scrambled siRNA plasmid and untransduced A549 cells. siRNA-mediated inhibition of cyclin D1 expression represents a promising antigrowth and antimetastatic strategy for cancer gene therapy, particularly for non-small cell lung cancers. It is the reason for inhibiting tumor growth so that cyclin D1 siRNA can inhibit the cell cycle progression. In addition, the mechanism of inhibiting tumor metastasis was related to the decrease in the expression of MMP-2, RhoA, and Rac1 after cyclin D1 was decreased by cyclin D1 siRNA.

Autocrine factors sustain glioblastoma stem cell self-renewal.

Glioblastoma stem cells are able to reform original glioblastoma and express the neural stem cell marker CD133 and Nestin. They can self-renew and proliferate in tumor sphere medium containing EGF, bFGF and LIF that is known to be permissive for stem cell proliferation. In this study, we found that neurosphere-like colonies appeared after the human primary glioblastoma cells had been switched into pure DMEM/F12 medium. We investigated whether tumor spheres formed in pure DMEM/F12 medium possess the characteristics of glioblastoma stem cells. We identified that the tumor sphere cells were cancer stem cells of glioblastoma and they can self-renew and proliferate in pure DMEM/F12 medium. Glioblastoma cells can secrete several factors that result in autocrine motility signaling and stimulate glioma invasion. We hypothesized that an essential autocrine signal promotes the self-renewal and proliferation of human glioblastoma stem cells in pure DMEM/F12 medium. Then, expression of EGF and bFGF in glioblastoma stem cells were analyzed. Both the mRNA and protein of EGF and bFGF were detected in three human glioblastoma stem cells. Our findings suggest that autocrine of EGF and bFGF may sustain the self-renewal of glioblastoma stem cells.

The co-transfection of p16(INK4a) and p14(ARF) genes into human lung cancer cell line A549 and the effects on cell growth and chemosensitivity.

Two functionally and structurally different proteins, p16(INK4a) and p14(ARF), encoded by the gene INK4a/ARF located at 9p21 are cyclin-dependent kinase (cdk) inhibitors and important cell cycle regulators. More and more evidences have been accumulated to show that the exogenous p16(INK4a) or p14(ARF) can inhibit the cell growth and/or induce the apoptosis. But it is still unclear if they can play positive role when combine with the conventional chemotherapy in cancer treatment. Here we show that cationic liposome-mediated gene transfection of INK4a/ARF into lung cancer cell line A549, in which the INK4a/ARF locus was lost, suppressed the growth and induced apoptosis. When treated with five different chemotherapy drugs with different mechanism after the transfection, A549 got an increased chemosensitivity for adriamycin and cisplatin and an unchanged result for topotecan, taxol or vinorelbine. The results indicated that cell cycle redistribution and increased apoptosis index after transfection might be the main explanation for the enhanced chemosensitivity. The combination of gene therapy with conventional chemotherapy is not always better than single chemotherapy. This trial will be of benefit to the treatment of lung cancer when combine the conventional chemotherapy and gene therapy in the future.

[Gene transfection of Livin isoforms into A549 cell line and its effect on cell growth and sensitivity to chemotherapy and radiotherapy].

OBJECTIVE: To express Livin alpha & beta in A549 cells by using gene transfection, and to observe its effect on cell growth and cell sensitivity to chemotherapy drugs and radiation. METHODS: Eukaryotic expression vectors of Livin alpha & beta were transfected into A549 cells and cell clones with stable expression were obtained. Livin alpha & beta expression levels in the transfected A549 cells were assessed at mRNA level and protein level, respectively. Cell growth status was assessed by biological features. MTT was performed to test effects of Livin on sensitivity of the A549 cells to chemotherapy drugs and radiation, and cell cycle analysis was performed to evaluate cell apoptosis. RESULTS: After transfection, positive cells, especially A549 cells expressing Livin, showed an increase of about 20% in colony-forming ability, a shorter doubling time (P < 0.05) and lower sensitivity to chemotherapy drugs and radiation (P < 0.01). Only 0.2% of the cells committed apoptosis with 10 Gy radiation. CONCLUSION: Livin isoforms, especially Livin alpha, are implicated in genesis and development of lung cancer, thus may be an important mechanism for drug resistance of lung cancer cells.