Active-specific immunotherapy for non-small cell lung cancer

Activation of the IL-4/STAT6 Signaling Pathway Promotes Lung Cancer Progression by Increasing M2 Myeloid Cells

Emerging evidence shows that signal transducer and activator of transcription 6 (STAT6) plays critical roles in tumor development. We previously found high-level expression of STAT6 in human lung adenocarcinoma and squamous cell carcinoma, specifically in infiltrated immune cells located in the lung interstitium. Nevertheless, the role of STAT6 signaling in lung carcinogenesis and lung cancer proliferation and its underlying mechanisms remain unclear. This study aimed to investigate the role of STAT6 and the interaction between STAT6 and the tumor microenvironment in pulmonary tumorigenesis. We established a murine model of primary lung carcinogenesis in STAT6-deficient (STAT6^−/−) and STAT6 wild-type (WT) BALB/c mice using the carcinogen urethane. Two-month-old male mice were intraperitoneally injected with urethane (1 g/kg) dissolved in phosphate buffered saline (PBS). Primary tumors were monitored in vivo by positron emission tomography scanning. At 4, 6, and 9 months after urethane injection, lung tumors were harvested from the STAT6^−/− and WT mice for analysis. Small interfering RNA was used to downregulate the expression of STAT6 in tumor cells. Fluorescence activated cell sorting analysis was used to analyze fluorescence-conjugated cell markers. Transwell assays were used in coculturing experiments. STAT6 protein expression was detected by Western blotting, immunohistochemistry, and immunofluorescence. STAT6 mRNA expression was detected by quantitative real time-polymerase chain reaction. Cell Counting Kit-8 and colony formation assays were performed to evaluate cell proliferation. We detected high expression of STAT6 in CD11b⁺ cells of lung carcinoma. Our results indicate that STAT6 deficiency inhibits carcinogen-induced tumor growth and improves prognosis. STAT6 deficiency also decreased the mobilization and differentiation of CD11b⁺ cells. STAT6 deficiency in CD11b⁺ cells but not tumor cells decreased interleukin (IL)-4 secretion and the differentiation of CD11b⁺ cells into M2 macrophage cells. In conclusion, our findings indicate that IL-4/STAT6 signaling in CD11b⁺ cells promotes lung cancer progression by triggering an IL-4 positive feedback loop and increasing M2 myeloid cells. STAT6 may be a new therapeutic target for the prevention and treatment of lung cancer.

TREM-2 serves as a negative immune regulator through Syk pathway in an IL-10 dependent manner in lung cancer

During infection, triggering receptor expressed on myeloid cells-2 (TREM-2) restrains dendritic cells (DCs) and macrophages (MΦs) phagocytosis, as well as reduces pro-inflammatory cytokines release through DNAX-activation protein 12 (DAP12) signaling. However, the role of TREM-2 signaling in cancer has never been elucidated. In the current study, we found that TREM-2 was up-regulated on peripheral blood monocytes in tumor-bearing host. More TREM-2⁺DCs were detected in the lung of 3LL tumor-bearing mice. On the other hand, the level of TREM-2 on pulmonary MΦs positively correlated with the pathological staging of lung cancer. However, surgical or chemotherapeutic reduction of tumor burden led to the obvious decline of TREM-2. In vitro, TREM-2 expression of bone marrow (BM)-derived DCs and MΦs was induced by conditional medium (CM) containing the supernatant of 3LL cells. TREM-2⁺DCs from CM and/or tumor-bearing mice held altered phenotypes (CD80^LowCD86^LowMHCII^Low) and impaired functions, such as, reduced interleukin (IL)-12 secretion, increased IL-10 production, and weakened ovalbumin (OVA)-endocytic capacity; also developed potent inhibitory effect on T cell proliferation that could be partially reversed by TREM-2 blockage. Moreover, spleen tyrosine kinase (Syk) inhibitor restrained IL-10 production of TREM-2⁺DC. Remarkably, IL-10 neutralizing antibody and Syk inhibitor both lowered the suppressive potential of TREM-2⁺DCs in T cell proliferation. Also, adoptive transfer of this TREM-2⁺DCs accelerated the tumor growth rather than jeopardized survival in lung cancer-bearing mice. In conclusion, these results indicate that TREM-2 might act as a negative immuno-regulatory molecule through Syk pathway in an IL-10 dependent manner and partially predicts prognosis in lung cancer patients.

Immunotherapy in non-small cell lung cancer: the clinical impact of immune response and targeting

Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related death worldwide. In recent years, through a better understanding of the interactions between the immune system and tumor cells (TC), immunotherapy has emerged as a promising therapeutic strategy. Chemotherapy has long been reported to interfere with the immune response to the tumor and conversely, anti-tumor immunity may add to those effects. Anti-tumor vaccines, such as MAGE-A3, Tecetomide, TG4010, CIMAvax, tumor cell vaccines and dendritic cell (DC) vaccines emerged as potent inducers of the immune response against the tumor. More recently the approval of the anti-programmed cell death 1 (anti-PD-1) monoclonal antibodies nivolumab and pembrolizumab for previously treated advanced squamous and non-squamous NSCLC, as well as other immune checkpoint inhibitors delivering promising results, has radically transformed the therapeutic landscape of NSCLC. Combination strategies now appear as the next step. Notwithstanding these successes, immunotherapy still holds significant drawbacks and currently several improvements are needed before routine use in clinical practice, including identification of robust biomarkers for optimal patient selection, as well as defining the best way to evaluate response.

Immunotherapy for lung cancer: for whom the bell tolls?

Lung cancer is the leading cause of cancer-related death and accounts for approximately 30% of all cancer deaths. Despite the recent developments in personalized therapy, the prognosis in lung cancer is still very poor. Immunotherapy is now emerging as a new hope for patients with lung cancer. It is well known that standard chemotherapeutic regimens have devastating effects for the patient's immune system. Therefore, the aim of immunotherapy is to specifically enhance the immune response against the tumour. Recently, many trials addressed the role of such therapies for metastatic non-small cell lung cancer (NSCLC) treatment: ipilimumab, tremelimumab, nivolumab and pembrolizumab are immunotherapeutic agents of high relevance in this field. Anti-tumour vaccines, as well as dendritic cell-based therapies, have emerged as potent inducers of immune response against the tumour. Herein, we will review some of the most promising cancer immunotherapies, highlighting their advantages and try to understand, in an immunological perspective, the missteps associated with the current treatments for cancer.

Actual status of therapeutic vaccination in non-small cell lung cancer

Lung cancer is the leading cause of cancer-related death worldwide. Although treatment methods such as surgery, radiotherapy and/or chemotherapy have improved, prognosis remains unsatisfactory, and developing new therapeutic strategies is still an urgent matter. Immunotherapy is a novel therapeutic approach wherein activated immune cells can specifically kill tumour cells. Several lung cancer vaccines have demonstrated prolonged survival time in phase II and III trials, and several clinical trials are under investigation. However, many clinical trials involving cancer vaccination with defined tumour antigens have shown this method to work only in a small number of patients. Cancer immunotherapy is not completely effective in eradicating tumour cells because they evade host immune control.

Treatment-related lymphopenia in patients with stage III non-small-cell lung cancer

BACKGROUND

This study sought to estimate the severity, etiology, and clinical importance of treatment-related lymphopenia in patients with stage III non-small-cell lung cancer.

METHODS

Serial lymphocyte counts and survival were analyzed retrospectively in 47 patients accounting for known prognostic factors.

RESULTS

Total lymphocyte counts (TLCs) were normal before therapy and did not change following neoadjuvant chemotherapy. Following radiation, TLC fell by 67% (median 500 cells/mm(3), p <.00001). Multivariate analysis revealed an association between severe TLC and survival (HR 1.70, 95% CI: 0.8-3.6).

CONCLUSIONS

Rapid and severe lymphopenia occurred in 50% of patients following radiation which was associated with reduced survival.

The efficacy of the inhalation of an aerosolized Group A streptococcal preparation in the treatment of lung cancer

OBJECTIVE

To observe the efficacy of the inhalation of an aerosolized group A streptococcal (GAS) preparation in treating orthotopic lung cancer in mouse models and assess the feasibility, safety, and effectiveness of this administration mode for lung cancer.

METHODS

Lewis lung carcinoma (LLC) cell strains were administered via intrathoracic injection to establish orthotopic lung cancer mouse models. After the tumor-bearing models were successfully established, as confirmed by computed tomography, the mice were administered by inhalation with an aerosolized GAS preparation (GAS group) or aerosolized normal saline (control group). The anti-tumor effect of the aerosolized GAS preparation was evaluated histologically; meanwhile, the survival and quality of life were compared between these two groups.

RESULTS

The aerosolized GAS preparation showed remarkably anti-tumor effect, causing the necrosis of the orthotopic lung cancer cells in tumor-bearing mice. Furthermore, mice in the GAS group had significantly better quality of life and longer survival than those in control group.

CONCLUSIONS

The inhalation of aerosolized GAS preparation may be a feasible, safe and effective solution for lung cancer.

Improving lung cancer survival; time to move on

BACKGROUND

During the past decades, numerous efforts have been made to decrease the death rate among lung cancer patients. Nonetheless, the improvement in long-term survival has been limited and lung cancer is still a devastating disease.

DISCUSSION

With this article we would like to point out that survival of lung cancer could be strongly improved by controlling two pivotal prognostic factors: stage and treatment. This is corresponding with recent reports that show a decrease in lung cancer mortality by screening programs. In addition, modulation of the patient's immune system by immunotherapy either as monotherapy or combined with conventional cancer treatments offers the prospect of tailoring treatments much more precisely and has also been shown to lead to a better response to treatment and overall survival of non-small cell lung cancer patients.

SUMMARY

Since only small improvements in survival can be expected in advanced disease with the use of conventional therapies, more research should be focused on lung cancer screening programs and patient tailored immunotherapy with or without conventional therapies. If these approaches are clinically combined in a standard multidisciplinary policy we might be able to advance the survival of patients with lung cancer.

Maintenance treatment with chemotherapy and immunotherapy in non-small cell lung cancer: a case report

A 53-years-old woman was diagnosed with lung adenocarcinoma state IV (synchronous pleural involvement) in April 2009. First-line systemic treatment included six cycles of Carboplatin, Paclitaxel, and Bevacizumab. Partial response was achieved. Maintenance therapy with Bevacizumab and Pemetrexed was given from September 2009 to February 2010. No response changes were observed. Immunotherapy was initiated, and then Pemetrexed was given with the same disease status. Both treatments were well tolerated. Immunotherapy toxicity included reaction at the site of injection grade 2. At present, the patient is still on this treatment. Given the poor prognosis of patients with advanced lung cancer, the combination of both treatments during the stable phase of the disease may improve progression-free survival.

Tumor-induced CD8+ T-cell dysfunction in lung cancer patients

Lung cancer is the leading cause of cancer deaths worldwide and one of the most common types of cancers. The limited success of chemotherapy and radiotherapy regimes have highlighted the need to develop new therapies like antitumor immunotherapy. CD8+ T-cells represent a major arm of the cell-mediated anti-tumor response and a promising target for developing T-cell-based immunotherapies against lung cancer. Lung tumors, however, have been considered to possess poor immunogenicity; even so, lung tumor-specific CD8+ T-cell clones can be established that possess cytotoxicity against autologous tumor cells. This paper will focus on the alterations induced in CD8+ T-cells by lung cancer. Although memory CD8+ T-cells infiltrate lung tumors, in both tumor-infiltrating lymphocytes (TILs) and malignant pleural effusions, these cells are dysfunctional and the effector subset is reduced. We propose that chronic presence of lung tumors induces dysfunctions in CD8+ T-cells and sensitizes them to activation-induced cell death, which may be associated with the poor clinical responses observed in immunotherapeutic trials. Getting a deeper knowledge of the evasion mechanisms lung cancer induce in CD8+ T-cells should lead to further understanding of lung cancer biology, overcome tumor evasion mechanisms, and design improved immunotherapeutic treatments for lung cancer.

Effect of targeted silencing of hTERT mRNA by lentivirus-mediated siRNA on A549 lung cancer cells in vitro

In our present study, we took advantage of the characteristics of RNA interference technology, which can efficiently, stably, and specifically silence target genes, and designed a small interfering RNA (siRNA) that could specifically target hTERT mRNA. We used a lentiviral vector (LV) to deliver the hTERT siRNA into telomerase-positive A549 lung cancer cells and investigated the effect of hTERT siRNA on the hTERT mRNA levels, hTERT protein levels, cell proliferation, and apoptosis in the lung cancer cells. The results from quantitative PCR, Western blotting, and the MTT assay showed that the expression levels of both hTERT mRNA and protein in the cells were significantly decreased and that the cell proliferation rate started to significantly slow down at 48 h after transfection with hTERT-LV. Our study demonstrated that siRNA sequences specifically targeting hTERT mRNA, which were packaged into lentivirus particles and then used to transfect the lung cancer cell line A549, can specifically silence the mRNA of the target gene, hTERT, and then reduce the hTERT protein expression level, which, in turn, reduces cell proliferation, inhibits cell growth, and induces apoptosis.

The therapeutic function of the chemokine RANTES on the H22 hepatoma ascites model

This study aimed at analyzing the therapeutic function of the chemokine RANTES on the H22 hepatoma ascites model and preliminarily explore the mechanism of RANTES in malignant ascites to provide an important reference for applying chemokines in anti-tumor therapy. The murine H22 hepatoma ascites model was used. Three treatment groups were analyzed: a RANTES treatment group, an IL-2 control group, and an NS control group. Two regimens of early treatment and late treatment were designed, and the therapeutic effect of RANTES on malignant ascites was studied by measuring changes in mouse body weight and abdominal circumference and observing the survival time. The expression of TNF-α, IFN-γ, TGF-β1, and MCP-1 in mouse ascites was detected by ELISA, and the chemotactic function of RANTES on B lymphocytes and T lymphocytes was analyzed by flow cytometry. In the early and late treatment regimens, RANTES could effectively inhibit the increase in mouse body weight and abdominal circumference in the murine H22 hepatoma ascites model. The secretion of TNF-α and IFN-γ, which had anti-tumor effects, was higher in the RANTES treatment group than in the control groups (P < 0.05), whereas the secretion of TGF-β1 and MCP-1, which promoted tumor growth, invasion, and metastasis, was lower than in the control groups (P < 0.05). RANTES had chemotactic effects on CD4(+) and CD8(+) T lymphocytes; therefore, the percentage of CD3, CD4, and CD8 in the mouse ascites in the RANTES treatment group was significantly higher than in the NS control and IL-2 treatment groups, and the CD4/CD8 ratio was also significantly higher. RANTES can effectively inhibit the increase in body weight and abdominal circumference and significantly extend survival time in mice in the H22 hepatoma ascites model.

Effects of BTG2 on proliferation inhibition and anti-invasion in human lung cancer cells

The objective of the study was to investigate the impact of the B cell translocation gene 2 (BTG2) on lung cancer cell growth, proliferation, metastasis, and other biological characteristics and to provide experimental evidence for the biological treatment of human lung cancer. A pcDNA3.1-BTG2 eukaryotic expression vector was constructed and transfected into the human lung cancer cell line A549. The biological changes in the BTG2-expressing cells were analyzed using growth curves, the MTT (tetrazolium) assay, propidium iodide (PI) staining, and the Transwell invasion chamber. Additionally, Western blotting was used to determine the impact of BTG2 on the protein expression of cyclin D1, MMP-1, and MMP-2. Compared to the empty vector-transfected A549 cells or the mock-transfected A549 cells, the pcDNA3.1-BTG2-transfected A549 cells grew significantly slower. No significant differences were detected between the empty vector-transfected group and the mock-transfected A549 cells. The growth curve analysis and the PI staining showed that the pcDNA3.1-BTG2-transfected cells grew significantly slower than the empty vector-transfected A549 cells (P < 0.05). The cell invasion assay results suggested that the invasion rate of the pcDNA3.1-BTG2-transfected A549 cells was significantly slower than the invasion rate of the empty vector-transfected group and the mock-transfected group (P < 0.05). The overexpression of BTG2 may inhibit the protein expression of cyclin D1, MMP-1, and MMP-2 in A549 cells. The overexpression of BTG2 may inhibit the growth, proliferation, and invasiveness of the A549 human lung cancer cell line.