Tumor antigens in thoracic malignancy

Phase I Trial of Intratumoral Injection of CCL21 Gene-Modified Dendritic Cells in Lung Cancer Elicits Tumor-Specific Immune Responses and CD8+ T-cell Infiltration

Purpose: A phase I study was conducted to determine safety, clinical efficacy, and antitumor immune responses in patients with advanced non-small cell lung carcinoma (NSCLC) following intratumoral administration of autologous dendritic cells (DC) transduced with an adenoviral (Ad) vector expressing the CCL21 gene (Ad-CCL21-DC). We evaluated safety and tumor antigen-specific immune responses following in situ vaccination (ClinicalTrials.gov: NCT01574222).Experimental Design: Sixteen stage IIIB/IV NSCLC subjects received two vaccinations (1 × 10⁶, 5 × 10⁶, 1 × 10⁷, or 3 × 10⁷ DCs/injection) by CT- or bronchoscopic-guided intratumoral injections (days 0 and 7). Immune responses were assessed by tumor antigen-specific peripheral blood lymphocyte induction of IFNγ in ELISPOT assays. Tumor biopsies were evaluated for CD8⁺ T cells by IHC and for PD-L1 expression by IHC and real-time PCR (RT-PCR).Results: Twenty-five percent (4/16) of patients had stable disease at day 56. Median survival was 3.9 months. ELISPOT assays revealed 6 of 16 patients had systemic responses against tumor-associated antigens (TAA). Tumor CD8⁺ T-cell infiltration was induced in 54% of subjects (7/13; 3.4-fold average increase in the number of CD8⁺ T cells per mm²). Patients with increased CD8⁺ T cells following vaccination showed significantly increased PD-L1 mRNA expression.Conclusions: Intratumoral vaccination with Ad-CCL21-DC resulted in (i) induction of systemic tumor antigen-specific immune responses; (ii) enhanced tumor CD8⁺ T-cell infiltration; and (iii) increased tumor PD-L1 expression. Future studies will evaluate the role of combination therapies with PD-1/PD-L1 checkpoint inhibition combined with DC-CCL21 in situ vaccination. Clin Cancer Res; 23(16); 4556-68. ©2017 AACR.

Intrapulmonary administration of CCL21 gene-modified dendritic cells reduces tumor burden in spontaneous murine bronchoalveolar cell carcinoma

The antitumor efficiency of dendritic cells transduced with an adenovirus vector expressing secondary lymphoid chemokine (CCL21) was evaluated in a murine model of spontaneous bronchoalveolar cell carcinoma. The transgenic mice (CC-10 TAg) express the SV40 large T antigen (TAg) under the Clara cell promoter, develop bilateral, multifocal, and pulmonary adenocarcinomas, and die at 4 months as a result of progressive pulmonary tumor burden. A single intratracheal administration of CCL21 gene-modified dendritic cells (DC-AdCCL21) led to a marked reduction in tumor burden with extensive mononuclear cell infiltration of the tumors. The reduction in tumor burden was accompanied by the enhanced elaboration of type 1 cytokines [IFN-gamma, interleukin (IL)-12, and granulocyte macrophage colony-stimulating factor] and antiangiogenic chemokines (CXCL9 and CXCL10) but a concomitant decrease in the immunosuppressive molecules (IL-10, transforming growth factor-beta, prostaglandin E(2)) in the tumor microenvironment. The DC-AdCCL21 therapy group revealed a significantly greater frequency of tumor-specific T cells releasing IFN-gamma compared with the controls. Continuous therapy with weekly intranasal delivery of DC-AdCCL21 significantly prolonged median survival by >7 weeks in CC-10 TAg mice. Both innate natural killer and specific T-cell antitumor responses significantly increased following DC-AdCCL21 therapy. Significant reduction in tumor burden in a model in which tumors develop in an organ-specific manner provides a strong rationale for further evaluation of intrapulmonary-administered DC-AdCCL21 in regulation of tumor immunity and genetic immunotherapy for lung cancer.

Role of inflammation in mouse lung tumorigenesis: a review

Peritumoral and intratumoral macrophages are associated with human and mouse lung cancer The mouse model allows manipulation of the macrophage population to experimentally evaluate its contribution to tumor growth. Genetic and pharmacologic strategies also permit testing the invol vement of specific inflammatory mediators in tumor progression. Among those endogenous mediators thus identified are interleukin (IL)-10, glucocorticoids, prostacyclin, nitric oxide, and surfactant apoprotein D (SP-D); serum SP-D levels are a useful biomarker to monitor tumor growth rate. The importance of understanding the mutually antagonistic roles of individual prostaglandins downstream from cycloxygenase (COX) and how this affects the efficacy of COX-inhibitory drugs is discussed. Promising drug candidates include synthetic glucocorticoids such as budesonide and the sulfone derivative of sulindac, apotosyn.

Treatment of lung cancer using clinically relevant oral doses of the cyclooxygenase-2 inhibitor rofecoxib: potential value as adjuvant therapy after surgery

OBJECTIVE

To investigate the uses and limitations of cyclooxygenase- (COX) 2 inhibition using clinically relevant doses of oral rofecoxib in the treatment of murine models of non-small-cell lung cancer (NSCLC).

SUMMARY BACKGROUND DATA

Overexpression of COX-2 has been reported in lung cancer. Several studies have demonstrated that high doses of COX-2 inhibitors could inhibit the growth of rodent and human lung cancer cell lines. The potential uses and limitations of COX-2 inhibition at doses equivalent to those currently approved for use in humans have not been well studied.

METHODS

Three murine NSCLC cell lines were injected into the flanks of mice to establish tumor xenografts. Mice were treated orally with low doses of a COX-2 inhibitor (rofecoxib chow, 0.0075%). Mechanisms were evaluated by analysis of tumor-infiltrating lymphocytes. To study rofecoxib as adjuvant therapy, large established tumors (14-18 days after tumor inoculation) were surgically debulked and animals were treated with rofecoxib starting 3 days before surgery. Recurrence of the tumor after debulking was monitored.

RESULTS

Rofecoxib significantly slowed the growth of small (0-120 mm) tumors (P < 0.01-0.05) in all 3 cell lines, with higher efficacy in the more immunogenic tumors. Minimal responses were noted in larger tumors. Rofecoxib appeared to augment CD8 T cell infiltration in immunogenic tumors. Rofecoxib significantly reduced the recurrence rate after debulking (P < 0.01).

CONCLUSIONS

Clinically relevant doses of the COX-2 inhibitor rofecoxib given orally were effective in inhibiting the growth of small (but not large) tumors in 3 murine NSCLC cell lines tested and in preventing recurrences after surgical debulking. Depending on the immunogenicity of human tumors, COX-2 inhibition might be useful as adjuvant therapy for surgically resectable NSCLC.

Intratumoral administration of dendritic cells overexpressing CCL21 generates systemic antitumor responses and confers tumor immunity

To achieve in situ tumor antigen uptake and presentation, intratumoral administration of ex vivo-generated, gene-modified murine bone marrow-derived dendritic cells (DC) was used in a murine lung cancer model. To attract mature host DC and activated T cells at the tumor site, the DC were transduced with an adenoviral vector expressing secondary lymphoid tissue chemokine (CCL21/SLC). Sixty percent of the mice treated with 10(6) DC-AdCCL21 intratumorally (7-10 ng/ml/10(6) cells/24 h of CCL21) at weekly intervals for 3 weeks showed complete tumor eradication, whereas only 25% of mice had complete resolution of tumors when mice were treated with fibroblasts expressing CCL21. In contrast only 12% of the mice treated with unmodified or control vector modified DC (DC-AdCV) showed complete tumor eradication. DC-AdCCL21 administration led to increases in the CD4(+), CD8(+), and CD3(+)CXCR3(+) T cells, as well as DC expressing CD11c(+) DEC205(+). CD4(+)CD25(+) T-regulatory cells infiltrating the tumors were markedly reduced after DC-AdCCL21 therapy. The tumor site cellular infiltrates were accompanied by the enhanced elaboration of granulocyte macrophage colony-stimulating factor, IFN-gamma, MIG/CXCL9, IP-10/CXCL10, and interleukin 12, but decreases in the immunosuppressive mediators transforming growth factor beta and prostaglandin E(2). DC-AdCCL21-treated tumor-bearing mice showed enhanced frequency of tumor-specific T lymphocytes secreting IFN-gamma, and tumor protective immunity was induced after DC-AdCCL21 therapy. In vivo depletion of IP-10/CXCL10, MIG/CXCL9, or IFN-gamma significantly reduced the antitumor efficacy of DC-AdCCL21. These findings provide a strong rationale for the evaluation of DC-AdCCL21 in cancer immunotherapy.

Interleukin-7 gene-modified dendritic cells reduce pulmonary tumor burden in spontaneous murine bronchoalveolar cell carcinoma

The antitumor efficiency of dendritic cells transduced with an adenovirus vector expressing interleukin (IL)-7 (DC-AdIL-7) was evaluated in a murine model of spontaneous bronchoalveolar cell carcinoma. These transgenic mice (CC-10 TAg), expressing the SV40 large T antigen under the Clara cell promoter, develop bilateral multifocal pulmonary adenocarcinomas and die at 4 months as a result of progressive pulmonary tumor burden. Injection of DC-AdIL-7 in the axillary lymph node region (ALNR) weekly for 3 weeks led to a marked reduction in tumor burden with extensive lymphocytic infiltration of the tumors and enhanced survival. The antitumor responses were accompanied by the enhanced elaboration of interferon (IFN)-gamma and IL-12 as well as an increase in the antiangiogenic chemokines, IFN-gamma-inducible protein 10 (IP-10/CXCL10) and monokine induced by IFN-gamma (MIG/CXCL9). In contrast, production of the immunosuppressive mediators IL-10, transforming growth factor (TGF)-beta, prostaglandin E(2) (PGE(2)), and the proangiogenic modulator vascular endothelial growth factor (VEGF) decreased in response to DC-AdIL-7 treatment. Significant reduction in tumor burden in a model in which tumors develop in an organ-specific manner provides a strong rationale for further evaluation of DC-AdIL-7 in regulation of tumor immunity and its use in lung cancer genetic immunotherapy.