An orally administered DNA vaccine targeting vascular endothelial growth factor receptor-3 inhibits lung carcinoma growth.

Lung cancer is the leading cause of mortality and 5-year survival rate is very low worldwide. Recent studies show that vascular endothelial growth factor receptor-3 (VEGFR-3) signaling pathway contributes to lung cancer progression. So we hypothesize that an oral DNA vaccine that targets VEGFR-3 carried by attenuated Salmonella enterica serovar typhimurium strain SL3261 has impacts on lung cancer progression. In this study, the oral VEGFR-3-based vaccine-immunized mice showed appreciable inhibition of tumor growth and tumor lymphatic microvessels in lung cancer mice model. Moreover, the oral VEGFR-3-based vaccine-immunized mice showed remarkable increases in both VEGFR-3-specific antibody levels and cytotoxic activity. Furthermore, the oral VEGFR-3-based vaccine-immunized mice showed a significant increase in the levels of T helper type 1 (Th1) cell intracellular cytokine expression (IL-2, IFN-γ, and TNF-α). After inoculation with murine Lewis lung carcinoma (LLC) cells, CD4(+) or CD8(+) T cell numbers obviously declined in control groups whereas high levels were maintained in the oral VEGFR-3-based vaccine group. These results demonstrated that the oral VEGFR-3-based vaccine could induce specific humoral and cellular immune responses and then significantly inhibit lung carcinoma growth via suppressing lymphangiogenesis.

[Expression of transcription factor SOX4 and its clinical significance in female lung cancer patients in Xuanwei area, Yunnan Province].

OBJECTIVE: To investigate the expression of transcription factor SOX4 in lung cancer tissues of female patients in Xuanwei area, Yunnan Province, and explore its correlation with clinicopathological characteristics and prognosis of the female patients. METHODS: Real-time PCR was applied on lung cancer specimens and their corresponding normal lung tissues from 96 female cases of Xuanwei area to assess the expression of SOX4 mRNA. Immunohistochemical staining was performed to investigate the SOX4 protein expression, and further to elucidate its correlation with clinicopathological characteristics and prognosis. RESULTS: The expression level of SOX4 mRNA in the cancer tissues (2.53 ± 1.65) was significantly higher than that of matched normal tissues (1.43 ± 1.14, P = 0.003). Immunohistochemical staining showed that there were 53.1% (51/96) positive expression of SOX4 protein in the cancer tissue and only 26.0% (25/96) in matched normal tissue (P < 0.001). The expression of SOX4 protein had a significant correlation with clinical stage, lymph node metastasis and differentiation of tumor (P < 0.05). The survival analysis by Kaplan-Meier method showed that patients with positive expression of SOX4 protein, lymph node metastasis and advanced tumor stage had a significantly shorter median survival time (P < 0.05). Cox regression survival analysis showed that pathological grade was a significant independent factor affecting prognosis. CONCLUSIONS: The expressions of SOX4 mRNA and protein are significantly up-regulated in Xuanwei female lung cancer patients. Patients with positive SOX4 expression have a shorter median survival time. SOX4 protein expression level combined with pathological grade can be used as a prognostic indicator of female lung cancer patients in Xuanwei area, Yunnan Province.

Orally administered DNA vaccine delivery by attenuated Salmonella typhimurium targeting fetal liver kinase 1 inhibits murine Lewis lung carcinoma growth and metastasis.

The vascular endothelial growth factor (VEGF) receptor 2 (VEGFR-2), also called fetal liver kinase 1 (FLK1) in mice and kinase insert domain receptor (KDR) in humans, is an endothelial cell specific receptor tyrosine kinase that mediates lung cancer angiogenesis. We hypothesized that an active immunotherapy approach targeting FLK1 may inhibit lung cancer growth and metastasis. To test this hypothesis, we evaluated whether immune responses to FLK1 could be elicited in mice by immunization with an orally administered DNA vaccine encoding the extracellular domain (ECD) of FLK1 (pcDNA3.1-FLK1(ECD)) carried by attenuated Salmonella typhimurium. We found that the vaccine was effective at protective antitumor immunity in Lewis lung carcinoma models in mice by breaking immune tolerance to FLK1 self-antigen. Both FLK1-specific humoral and cellular immune responses against endothelial cells can be induced in mice by immunization with pcDNA3.1-FLK1(ECD). Immunization with pcDNA3.1-FLK1(ECD) resulted in tumor suppression and prolonged survival in mice challenged with Lewis lung carcinomas cells. Experimental pulmonary metastases were strongly inhibited in pcDNA3.1-FLK1(ECD) immunized mice challenged with Lewis lung carcinoma cells. Thus, we conclude that the plasmid DNA vaccine encoding the extracellular domain of FLK1 could be an important component of FLK1 DNA vaccine to prevent lung carcinoma recurrence and metastasis after surgery.

MicroRNA-370 inhibits the growth and metastasis of lung cancer by down-regulating epidermal growth factor receptor expression.

Abnormal microRNA-370 (miR-370) expression has been frequently reported in several types of cancers, including lung cancer. However, the role and molecular mechanisms of miR-370 in regulating the growth and metastasis of lung cancer have not been clarified. Here, we show higher levels of epidermal growth factor receptor (EGFR), but lower levels of miR-370 expression in most human lung cancer cells and non-tumor cells. Induction of miR-370 over-expression significantly reduced the levels of EGFR expression and the EGFR 3'untranslated region (UTR)-regulated luciferase activity in XWLC-05 and H157 cells, suggesting that miR-370 may bind to the 3'UTR of EGFR mRNA. Compared with the control cells, induction of miR370 overexpression significantly inhibited the proliferation, clone formation capacity, migration and invasion of XWLC-05 and H157 cells while miR-370 inhibitor over-expression enhanced their tumor behaviors in vitro. Furthermore, miR-370 over-expression down-regulated the EGFR and hypoxia-inducible factor (HIF)-1α expression, and attenuated the extracellular single-regulated kinase (ERK)1/2 and AKT phosphorylation in XWLC-05 and H157 cells. In contrast, miR370 inhibitor over-expression increased the EGFR and HIF-1α expression as well as the ERK1/2 and AKT phosphorylation in XWLC-05 and H157 cells. Moreover, miR-370 over-expression significantly reduced the levels of EGFR and CD31 expression and inhibited the growth and lung metastasis of xenograft NSCLC tumors in mice. Our study indicates that miR-370 may bind to the 3'UTR of EGFR to inhibit EGFR expression and the growth, angiogenesis and metastasis of non-small cell lung cancer by down-regulating the ERK1/2 and AKT signaling.

Moderating effects and maintenance of lung cancer cellular immune functions by CIK cell therapy.

AIMS: To study the CIK cell treatment effects on regulation of cellular immune function disorders in patients with lung cancer, and to analyze the time characteristics. METHODS: Cellular immune function was assessed by FCM, and patients with functional disorders were randomly divided into two groups, one given CIK cell therapy within 18 months (5 courses) and the other the controls, which were followed up for 1 year with cellular immune functions tested once a month. RESULTS: There were 5 types of cellular immunity, 4 of which are disorders; after CIK treatment, the improvement rate of the 4 groups were 79.1%, 70.8%, 76.0% and 70.0%, intergroup differences not being statistically significant (P=0.675), all significantly higher than in the control group (P=0.000). The median maintenance times for the 4 groups were 10.4 months (9.76-11.04), 8.4 months (7.86-8.94), 9.8 months (9.20-10.4) and 7.9 months (6.25-9.55), respectively. CONCLUSIONS: CIK cells were able to improve the immune functions of patients with lung cancer, the rate of improvement and maintenance time being related to the immune function before the treatment and CIK-cell-therapy courses.