Nonsmall cell lung cancer therapy: insight into multitargeted small-molecule growth factor receptor inhibitors

Comprehensive bioinformatics analysis identifies several potential diagnostic markers and potential roles of cyclin family members in lung adenocarcinoma

Purpose

The aim of this study was to identify critical genes in lung cancer progression.

Methods

We downloaded and reanalyzed gene expression profiles from different public data-sets using comprehensive bioinformatics analysis. Differentially expressed genes (DEGs) were identified in lung adenocarcinoma tissues compared with adjacent nonmalignant lung tissues. The overlapping DEGs identified from different datasets were used for functional and pathway enrichment analyses and protein–protein interaction (PPI) analysis. Moreover, transcription factors (TFs) and miRNAs that regulated the overlapping DEGs were predicted, followed by a TF–miRNA–target network construction. Furthermore, survival analysis of genes was performed. Several genes were further validated by quantitative real-time PCR (qRT-PCR).

Results

A total of 647 overlapping upregulated genes and 979 overlapping downregulated genes were identified. The overlapping upregulated genes and downregulated genes were involved in different functions, such as cell cycle, p53 signaling pathway, immune response, and cell adhesion molecules (CAMs). Several genes belonging to the cyclin family, including CCNB1, CCNB2, and CCNA2, were hubs of the PPI network and TF–miRNA–target network. Additionally, genes, including NPAS2, GNG7, CHIA, and SLC2A1, were predicted to be prognosis-related DEGs. Gene expression profiles determined by bioinformatics analysis and qRT-PCR were highly comparable.

Conclusion

CCNB1, CCNB2, CCNA2, NPAS2, GNG7, CHIA, and SLC2A1 are promising targets for the clinical diagnosis and therapy of lung adenocarcinoma.

Cullin7 is required for lung cancer cell proliferation and is overexpressed in lung cancer

Ubiquitin ligase Cullin7 has been identified as an oncogene in some malignant diseases such as choriocarcinoma and neuroblastoma. However, the role of Cullin7 in lung cancer carcinogenesis remains unclear. In this study, we explored the functional role of Cullin7 in lung cancer cell proliferation and tumorigenesis and determined its expression profile in lung cancer. Knocking down Cullin7 expression by small interfering RNA (siRNA) in lung cancer cells inhibited cell proliferation and elevated the expression of p53, p27, and p21 proteins. The enhanced p53 expression resulted from activation of the DNA damage response pathway. Cullin7 knockdown markedly suppressed xenograft tumor growth in vivo in mice. Moreover, Cullin7 expression was increased in primary lung cancer tissues of humans. Thus, Cullin7 is required for sustained proliferation and survival of tumor cells in vitro and in vivo, and its aberrant expression may contribute to the pathogenesis of lung cancer. Thus, our study provided evidence that Cullin7 functions as a novel oncogene in lung cancer and may be a potential therapeutic target for lung cancer management.

Targeting of growth factors in the treatment of hepatocellular carcinoma: The potentials of polysaccharides

Hepatocellular carcinoma (HCC) has become a leading cause of cancer-associated mortality worldwide and is thus of great concern. Although various chemotherapeutic drugs are currently used for the treatment of HCC, severe side effects associated with these treatments have prompted interest in novel therapies, including the use of certain biological macromolecules such as polysaccharides. Several studies have shown that polysaccharides have anticancer and antiproliferative effects on HCC. Vascular endothelial growth factor, transforming growth factor β, epidermal growth factor and fibroblast growth factor may be effective targets for polysaccharides and may modulate tumor growth and immunity through increasing the expression levels of cytokines. The present review focuses on the ways in which growth factors contribute to the development of HCC, and on the anti-growth factor activities of natural and synthetic polysaccharides, as well as their effect on proinflammatory cytokines.

The antitumor effects of oncolytic adenovirus H101 against lung cancer

Lung cancer is the leading cause of cancer mortality in both men and women, with dismal survival rates due to late-stage diagnoses and a lack of efficacious therapies. The new treatment options with completely novel mechanism of therapeutic activity are needed for lung cancer to improve patient outcome. The present study was aimed at testing the efficacy of recombinant adenovirus H101 as an oncolytic agent for killing human lung cancer cell lines in vitro and in vivo. We assessed the coxsackievirus adenovirus receptor (CAR) expression on human lung cancer cell lines by RT-PCR and immunocytochemistry staining. Viral infectivity and viral replication in lung cancer cells was assayed by flow cytometry and real-time fluorescent quantitative PCR. After H101 treatment, cytotoxic effect, cell cycle progression and apoptosis were further examined by lactate dehydrogenase release assay and flow cytometry in vitro, respectively. In vivo, antitumor effects of H101 were assessed on SCID Beige mice xenografted with human lung cancer cells. Receptor characterization confirmed that human lung cancer cell lines expressed CAR receptor for adenovirus type 5. Lung cancer cells were sensitive to infection by the H101 virus. H101 infection and replication resulted in very potent cytotoxicity, G2/M phase arrest and cell lysis. In vivo, we also showed that H101 significantly inhibited tumor growth following intratumoral injection, with virus replication, cell degeneration and necrosis in the tumor tissue. These results have important implications for the treatment of human lung cancer.

MiR-133a is downregulated in non-small cell lung cancer: a study of clinical significance

Background

Despite present studies which suggested miR-133a as a promising biomarker for several cancers, there still exist no articles concerning the validated clinical significance of miR-133a in non-small cell lung cancer (NSCLC). Therefore, in this study, we targeted the correlation between miR-133a expression and clinicopathological significance in NSCLC patients.

Methods

The expression of miR-133a in 125 cases of NSCLC and their paired adjacent non-cancerous tissues was evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Meanwhile, the relationship between miR-133a expression and several clinicopathological parameters and patient survival was analyzed.

Results

The relative level of miR-133a was 2.0108 ± 1.3334 in NSCLC tissues, significantly lower than that of the adjacent non-cancerous lung tissues (3.6430 ± 2.2625, P = 0.019). The area under curve (AUC) of low expression of miR-133a to diagnose NSCLC was 0.760 (95% CI: 0.702 ~ 0.819, P < 0.001). MiR-133a expression was negatively correlated to lymphatic metastasis (r = −0.182, P = 0.042), tumor size (r = −0.253, P = 0.04), clinical TNM stages (r = −0.154, P = 0.087), and EGFR protein expression (r = −0.612, P < 0.001).

Conclusions

MiR-133a serves as a tumor-suppressive miRNA in human NSCLC, and its downregulation suggests deterioration in NSCLC patients.

RNAi-mediated A disintegrin and metalloproteinase 9 gene silencing inhibits the tumor growth of non-small lung cancer in vitro and in vivo

A disintegrin and metalloproteinase 9 (ADAM9) is a type I transmembrane protein that has been associated with cancer development and metastasis in various types of cancer. However, little is known about its role in non-small cell lung cancer (NSCLC). The aim of the present study was to evaluate whether downregulation of ADAM9 affects cell proliferation, apoptosis, migration and invasion in NSCLC. Thus, a recombinant lentiviral small hairpin RNA expression vector carrying ADAM9 was constructed and infected into the human NSCLC cell line A549. Cell proliferation, apoptosis, migration and invasion in vitro and tumor growth in vivo were determined following downregulation of ADAM9 by RNA interference-mediated ADAM9 gene silencing. It was found that downregulation of ADAM9 expression using an RNA silencing approach in A549 tumor cells significantly inhibited cell proliferation, migration and invasion, induced cell apoptosis in vitro, as well as suppressed in vivo tumor growth in an experimental mouse model of lung metastasis. These data indicate that ADAM9 is potentially an important new therapeutic target for the prevention of tumor growth in NSCLC.

Expression of IRAK1 in lung cancer tissues and its clinicopathological significance: a microarray study

The interleukin-1 receptor associated kinases 1 (IRAK1) is a down stream effector molecule of the toll like receptor (TLR) signaling pathway, which is involved in inflammation, autoimmunity and cancer. However, the role of IRAK1 in lung cancer remains unclarified. Herein, we investigated the protein expression and the clinicopathological significance of IRAK1 in 3 formalin-fixed paraffin-embedded lung cancer tissue microarrays by using immunohistochemistry, which included 365 tumor and 30 normal lung tissues. We found that the expression of IRAK1 in lung cancer was significantly higher compared with that in normal lung tissues (P=0.002). Receiver operating characteristic (ROC) curves were generated to evaluate the power of IRAK1 to distinguish lung cancer from non-cancerous lung tissue. The area under curve (AUC) of ROC of IRAK1 was 0.643 (95% CI 0.550~0.735, P=0.009). Additionally, IRAK1 expression was related to clinical TNM stage (r=0.241, P < 0.001), lymph node metastasis (r=0.279, P < 0.001) and tumor size (r=0.299, P < 0.001) in lung cancer. In the subgroup of non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), the positive rates of IRAK1 were both higher than that in the normal lung tissues (P=0.003, P=0.002, respectively). Further spearman analysis showed that IRAK1 protein in NSCLC was positive correlated with clinical TNM stage (r=0.222, P < 0.001), lymph node metastasis (r=0.277, P < 0.001), tumor size (r=0.292, P < 0.001) and distal metastasis (r=0.110, P=0.043). In conclusion, the expression of IRAK1 protein might be valuable in identifying patients with increased risks of lung cancer and might act as a target for diagnosis and gene therapy for lung cancer.

Genistein enhances the effect of cisplatin on the inhibition of non-small cell lung cancer A549 cell growth in vitro and in vivo

Although cisplatin (DDP) has been reported to be a promising antitumor therapy for non-small cell lung cancer (NSCLC), the effectiveness of the treatment remains limited due to an inherent tumor resistance to DDP. Genistein (GEN) is an abundant, naturally occurring isoflavonoid found in soy products that has been demonstrated to increase the anti-neoplastic activity of certain chemotherapy drugs in multiple tumor types. In the present study, DDP in combination with GEN was selected as a potential treatment to suppress tumor growth and simultaneously reduce the doses of the two drugs required for the treatment of NSCLC. Cell growth inhibition, apoptosis, cell cycle distribution and receptor signaling assays were conducted. In the in vivo study, DDP and GEN, either alone or in combination, were used to treat a xenograft model of the A549 cells. It was found that the combination of low concentrations of DDP and GEN induced significantly greater growth inhibition (P<0.01) and increased apoptosis in the A549 cells compared with either agent alone. In addition, DDP in combination with GEN could significantly suppress tumor growth in vivo compared with either agent alone. Combination treatment significantly suppresses constitutive phosphorylation of AKT and phosphoinositide-3 kinase, which may contribute to the inhibition of tumor growth. Overall, the present data suggested that GEN can increase the anti-neoplastic activity of DDP and that a combination of GEN and DDP is a potential drug candidate for the treatment of NSCLC.

Knockout of ADAM10 enhances sorafenib antitumor activity of hepatocellular carcinoma in vitro and in vivo

Sorafenib (SOR), a vascular endothelial growth factor receptor (VEGFR) inhibitor, is in wide clinical use for the treatment and prevention of liver cancer. However, extended SOR administration for hepatocellular carcinoma (HCC) induces drug resistance thereby limiting its efficacy and highlighting the need for improved therapeutic strategies. It has previously been demonstrated that knockout of a disintegrin and metalloproteinase 10 (ADAM10) via siRNA induced cancer apoptosis and decreased chemotherapy drug resistance. However, whether knockout of ADAM10 is able to decrease SOR resistance remains to be determined. Therefore, in the present study, the effect of siRNA-ADAM10 in combination with SOR was analyzed in HCC cell lines (HepG2) by inhibiting tumor growth and simultaneously reducing doses of SOR. Cell proliferation, apoptosis, migration, invasion and involvement in receptor signaling were determined after siRNA-ADAM10 was applied in combination with SOR treatment. Tumor growth ability in nude mice was also detected. The results showed that siRNA-ADAM10 in combination with SOR treatment in HCC cancer cells significantly suppressed proliferation, migration and invasion, and induced tumor apoptosis in vitro, and suppressed tumor growth in vivo. In addition, the results showed that knockout of ADAM10 by siRNA inhibited the constitutive phosphorylation of PI3K and AKT, which may contribute to the reduction of SOR resistance. Collectively, our experimental results indicate that knockout of ADAM10 by siRNA increased the SOR antitumor activity of liver cancer in vitro and in vivo, and that this additive combination is a promising drug candidate for treatment of HCC.

miR‑222 regulates sorafenib resistance and enhance tumorigenicity in hepatocellular carcinoma

The miR‑222 cluster has been demonstrated to function as oncomiR in human hepatocellular carcinoma (HCC). miR‑222 confers chemotherapy drug resistance in various cancers, including HCC. However, the effects and mechanisms by which miR‑222 regulates liver tumorigenicity and confers sorafenib (SOR) resistance remain unclear. Here we first investigated the miR‑222 effect on proliferation, cell cycle, apoptosis, migration and invasion of HCC. Our results demonstrated that miRNA inhibitors specially targeting miR‑222 significantly suppressed cellular proliferation, migration, invasion and G1/S transition of the cell cycle, and induced cell apoptosis in HepG2 cells. In addition, we investigated whether miR‑222 confers SOR resistance in HepG2 cells to explore it roles in acquisition of drug resistance. The results showed that miR‑222 inhibitors induced sensitivity to the antitumor effect of sorafenib in human HepG2 cells. Importantly, our study also showed that miR‑222 could regulate the expression of phosphorylation PI3K and AKT, which might contribute to miR‑222 conferred SOR resistance in HepG2 cells. In conclusion, this study demonstrates that miR‑222 can promote cell proliferation, migration and invasion, and decrease cell apoptosis, as well as enhance the resistance of HCC cells to sorafenib miR‑222 through activating the PI3K/AKT signaling pathway.

Knockdown of toll-like receptor 4 inhibits human NSCLC cancer cell growth and inflammatory cytokine secretion in vitro and in vivo

Toll-like receptor 4 (TLR4)-mediated signaling has been implicated in tumor cell invasion, survival and metastasis in several types of cancers. However, the expression of TLR4 in patients with non-small cell lung cancer (NSCLC) and its biological function in the development and progression of NSCLC have not been elucidated to date. Here, we sought to characterize the expression of TLR4 in patients with NSCLC and to investigate the biological roles of TLR4 in lung metastasis, cell invasion and survival. In this study, we found that TLR4 expression was elevated in most patients with NSCLC, and its expression levels correlated with key pathological characteristics, including tumor differentiation, stage and metastasis. Our data also showed that downregulation of TLR4 expression using an RNA silencing approach in A549 tumor cells significantly suppressed cell proliferation, cell migration and cell invasion, and induced tumor apoptosis in vitro, and suppressed tumor growth in vivo. In addition, we also found that downregulation of TLR4 expression significantly decreased cell TNF-α and IL-6 levels. Furthermore, we found that knockdown of TLR4 was able to significantly suppress constitutive phosphorylation of Akt and PI3K, which may contribute to the inhibition of tumor growth. These data suggest that TLR4 plays an important role in tumorigenic properties of human NSCLC, and that RNA interference-directed targeting of TLR4 could be used as a potential anticancer therapeutic target in NSCLC.

Current status of oncothermia therapy for lung cancer

Lung cancer is one of the most common malignant tumors, and it has the highest death rate. Oncothermia is a feasible and successful treatment for lung cancer. Results show a remarkable survival benefit for patients, with a good quality of life. The treatment has no, or in some cases mild, side-effects and could decrease the adverse effects of the complementary treatment. Applying oncothermia together with other treatment methods could increase the effects and result in better performance. A comparison of studies demonstrates a good correspondence in the data, which strengthens the reliability of the studies, and clearly shows the feasibility of the application of oncothermia to treating all kinds of pulmonary malignancies including non-small-cell and small-cell primary tumors, and all of the metastatic diseases of the pulmonary system.