Association of high cellular expression and plasma concentration of angiopoietin-like 4 with tongue cancer lung metastasis and poor prognosis.

Angiopoietin-like 4 (ANGPTL4) promotes cancer cell migration through vessels and has been implicated in cancer metastasis. Our previous study identified a robust increase in ANGPTL4 mRNA expression in lung-metastasized tongue cancer (TC) cells. Therefore, the present study investigated the association of ANGPTL4 with lung metastasis and outcomes of patient with TC. ANGPTL4 expression in TC cells was investigated by immunohistochemical staining. Patients were classified into 'low (0-30%)' and 'high (>30%)' ANGPTL4-expression groups based on the proportion of ANGPTL4-positive TC cells. The high ANGPTL4-expression group included 15 of 48 patients with TC. Notably, a significantly greater proportion of patients with lung metastasis exhibited a high rate of ANGPTL4-expressing cancer cells compared with patients without lung metastasis (P=0.029). The overall 5-year survival rate was lower in the high (27%) ANGPTL4-expression group compared with the low (68%) ANGPTL4-expression group. Univariate and multivariate analyses revealed that patients with high ANGPTL4 expression in TC cells exhibited significantly lower overall survival (OS) rates [hazard ratio (HR), 2.99; 95% confidence interval (95% CI), 1.34-6.69; P=0.008 and HR, 2.72; 95% CI, 1.14-6.51; P=0.024, respectively]. High plasma ANGPTL4 concentrations as measured by ELISA were associated with lung metastasis (P<0.001). The optimal cut-point for prediction of TC lung metastasis was 9.1 ng/ml (P<0.001; 95% CI, 7.2-10.9). The OS of patients with plasma ANPTL4 above the cut-point was significantly lower than that of patients with plasma ANGPTL4 ≤9.1 ng/ml (P<0.001). These results suggest that a high level of ANGPTL4 in cancer cells and plasma may predict lung metastasis and/or a poor prognosis of patients with TC.

Prostate cancer C5a receptor expression and augmentation of cancer cell proliferation, invasion, and PD-L1 expression by C5a.

BACKGROUND: The treatment of castration-resistant prostate cancer (CRPC) is a urological issue. Recent studies have revealed cancer promotion via the C5a-C5a receptor (C5aR) system. To establish a new therapeutic target for CRPC, we investigated an association of the system with CRPC progression and evasion from the antitumor immune responses. METHODS: C5aR and PD-L1 were immunostained in the prostate cancer (PC) tissues. The relationship of PC C5aR expression to clinicopathological parameters was analyzed. CRPC cell lines were examined for C5aR expression by real-time reverse transcription polymerase chain reaction, immunoblotting, and flow cytometry. C5a effects were examined on CRPC cell glutamine consumption, proliferation, invasion, and PD-L1 expression. RESULTS: PC cells expressed C5aR in 83 of the 161 patients (52%) and in three of the six CRPC patients. Basal cells, but not luminal cells, of noncancerous prostate glands expressed C5aR. Three CRPC cell lines expressed C5aR. C5a increased CRPC cell glutamine consumption 2.1-fold, proliferation 1.3-1.6-fold, and invasion 2-3-fold in a C5a-concentration and a C5aR-dependent manner. High expression of C5aR did not relate to the PC patients' clinical parameters but the PD-L1-positive rate was higher in the C5aR high-expression patients (37.5%) compared to low- or no expression patients (17.8%), and double-positive PC cells were present. C5a increased CRPC cell PD-L1 production 1.4-fold and cell-surface expression 2.6-fold. CONCLUSIONS: C5aR expression of PC cells in patients' tissues and C5a augmentation of C5aR-dependent CRPC proliferation, invasion, and PD-L1 expression suggested participation of the C5a-C5aR system in CRPC promotion and evasion from antitumor immune responses. Targeting this signaling pathway may provide a useful therapeutic option for CRPC.

C5a receptor expression is associated with poor prognosis in urothelial cell carcinoma patients treated with radical cystectomy or nephroureterectomy.

Patients with aggressive urothelial cell carcinoma (UCC) that undergo radical cystectomy or nephroureterectomy exhibit markedly high rates of disease recurrence and mortality. To select appropriate adjuvant thxerapies in addition to radical surgery, the identification of predictive prognostic markers for UCC patients is required. The aim of the present study was to identify such markers, by evaluating the association of UCC complement component 5 (C5) fragment a (C5a)receptor (C5aR) expression, detected using immunohistochemistry, with clinicopathological parameters and survival outcomes of UCC patients. The results revealed that C5aR was expressed in cancer cells, particularly at the invasive front, but not in noncancerous urothelial cells or adjacent cells. The UCC C5aR-positive rate of patients treated with radical surgeries was 73% (38/52) and the rate was 83% (20/24) at stages I-II of disease. No correlation between C5aR expression and any of clinicopathological parameters, which included gender, tumor location, World Health Organization grade, T stage, vessel invasion and stage of disease, was identified. However, univariate and multivariate analyses revealed that C5aR-positive UCC patients exhibited significantly lower overall survival rates [hazard ratio (HR), 3.14; 95% confidence interval (CI), 1.03-9.60; P=0.035 and HR, 3.92; 95% CI, 1.15-13.4; P=0.029, respectively] and 5-year survival rates (0.42 vs. 0.83) compared with C5aR-negative UCC patients. Furthermore, 5-year survival and disease-specific survival rates were lower in patients with C5aR-positive UCC (0.51; 95% CI, 0.30-0.71) than patients with C5aR-negative UCC (0.83; 95% CI, 0.62-1.00). These results indicate that UCC C5aR expression is predictive of poor patient outcomes and thus may lead to the appropriate selection of adjuvant therapies at earlier UCC stages, which could improve patient prognosis.

Influence of the C5a-C5a receptor system on breast cancer progression and patient prognosis.

BACKGROUND: Emerging evidence has shown activation of the complement system in cancer tissues and anaphylatoxin C5a release from C5 by cancer cells, suggesting C5a as a component in the cancer microenvironment. We revealed aberrant expression of C5a receptor (C5aR) in various human cancers and C5a-elicited enhancement of C5aR-expressing cancer cell invasion. METHODS: To explore an influence of the C5a-C5aR system in breast cancer (BC), we investigated BC C5aR expression in relation to clinicopathological parameters of the patients and an effect of C5a on BC cell proliferation. RESULTS: BC cell C5aR expression was observed immunohistochemically in 22 of 171 patients (13 %) and related to larger tumor size, higher nuclear grade and Ki-67 labeling index, presence of lymph node metastasis and advanced clinical stages. Interestingly, BC cells were C5aR-negative in all patients with BC in situ and C5aR-positive rate was high (38 %) in patients with hormone receptor-negative, namely triple-negative BC. For BC cells in metastasized lymph nodes, 12 of 22 patients (55 %) were C5aR-positive and included 7 patients with C5aR-negative BC in the primary site. Survival rate of patients with C5aR-positive BC was lower than that of patients with C5aR-negative BC. C5a enhanced proliferation of C5aR-expressing triple-negative BC cells in a C5aR-dependent manner. CONCLUSION: Relation of BC C5aR expression to tumor development and poor prognosis of the patients and proliferation enhancing effect of C5a on C5aR-expressing BC cells suggest that the C5a-C5aR system is closely associated with BC progression. This system may be a new target to treat BC patients, particularly with triple-negative BC.

Identification of the H2-Kd-restricted cytotoxic T lymphocyte epitopes of a tumor-associated antigen, SPARC, which can stimulate antitumor immunity without causing autoimmune disease in mice.

We previously reported that the secreted protein acidic and rich in cystein (SPARC) was overexpressed in melanoma in humans, and the serum SPARC level was useful as a novel tumor marker for melanoma. SPARC was also reported to be overexpressed in various human cancers. In this study, we asked whether SPARC-specific cytotoxic T lymphocytes (CTL) could induce antitumor immunity to SPARC-expressing tumor in mice or not as a preclinical study of SPARC-directed anticancer immunotherapy. Because of similarities in the structural motifs of major histocompatibility complex-binding peptides between H2-Kd and HLA-A24 (A*2402), the most common human leukocyte antigen class I allele in the Japanese population, we attempted to identify the H2-Kd-restricted SPARC epitope for CTL in BALB/c mice and we found that the mouse SPARC143-151 (DYIGPCKYI) and SPARC225-234 (MYIFPVHWQF) peptides could induce peptide-reactive CTL in BALB/c mice without causing autoimmune diseases. The immunization of mice with SPARC225-234 peptide-pulsed bone marrow-derived dendritic cells (BMDC) inhibited the growth of s.c. inoculated mouse mammary cancer cell line, N2C, expressing SPARC and these mice lived longer than the mice immunized with peptide-unpulsed BMDC. In conclusion, our study indicated that SPARC peptide-based cancer immunotherapy was effective and safe at least in a mouse tumor prevention model.

Regression of intestinal adenomas by vaccination with heat shock protein 105-pulsed bone marrow-derived dendritic cells in Apc(Min/+) mice.

Heat shock protein (HSP) 105 is overexpressed in various cancers, but is expressed at low levels in many normal tissues, except for the testis. A vaccination with HSP105-pulsed bone marrow-derived dendritic cells (BM-DC) induced antitumor immunity without causing an autoimmune reaction in a mouse model. Because Apc(Min/+) mice develop multiple adenomas throughout the intestinal tract by 4 months of age, the mice provide a clinically relevant model of human intestinal tumor. In the present study, we investigated the efficacy of the HSP105-pulsed BM-DC vaccine on tumor regression in the Apc(Min/+) mouse. Western blot and immunohistochemical analyses revealed that the tumors of the Apc(Min/+) mice endogenously overexpressed HSP105. Immunization of the Apc(Min/+) mice with a HSP105-pulsed BM-DC vaccine at 6, 8, and 10 weeks of age significantly reduced the number of small-intestinal polyps accompanied by infiltration of both CD4(+) and CD8(+) T cells in the tumors. Cell depletion experiments proved that both CD4(+) and CD8(+) T cells play a critical role in the activation of antitumor immunity induced by these vaccinations. These findings indicate that the HSP105-pulsed BM-DC vaccine can provide potent immunotherapy for tumors that appear spontaneously as a result of the inactivation of a tumor suppressor gene, such as in the Apc(Min/+) mouse model.

Immunization with heat shock protein 105-pulsed dendritic cells leads to tumor rejection in mice.

Recently, we reported that heat shock protein 105 (HSP105) DNA vaccination induced anti-tumor immunity. In this study, we set up a preclinical study to investigate the usefulness of dendritic cells (DCs) pulsed with mouse HSP105 as a whole protein for cancer immunotherapy in vivo. The recombinant HSP105 did not induce DC maturation, and the mice vaccinated with HSP105-pulsed BM-DCs were markedly prevented from the growth of subcutaneous tumors, accompanied with a massive infiltration of both CD4+ T cells and CD8+ T cells into the tumors. In depletion experiments, we proved that both CD4+ T cells and CD8+ T cells play a crucial role in anti-tumor immunity. Both CD4+ T cells and CD8+ T cells specific to HSP105 were induced by stimulation with HSP105-pulsed DCs. As a result, vaccination of mice with BM-DCs pulsed with HSP105 itself could elicit a stronger tumor rejection in comparison to DNA vaccination.

DNA vaccination of HSP105 leads to tumor rejection of colorectal cancer and melanoma in mice through activation of both CD4 T cells and CD8 T cells.

We report that HSP105, identified by serological identification of antigens by recombinant expression cloning (SEREX), is overexpressed in a variety of human cancers, including colorectal, pancreatic, thyroid, esophageal, and breast carcinoma, but is not expressed in normal tissues except for the testis. The amino acid sequences and expression patterns of HSP105 are very similar in humans and mice. In this study, we set up a preclinical study to investigate the usefulness of a DNA vaccine producing mouse HSP105 whole protein for cancer immunotherapy in vivo using BALB/c and C57BL/6 mice, Colon26, a syngeneic endogenously HSP105-expressing colorectal cancer cell line, and B16.F10, a melanoma cell line. The DNA vaccine was used to stimulate HSP105-specific T-cell responses. Fifty percent of mice immunized with the HSP105 DNA vaccine completely suppressed the growth of subcutaneous Colon26 or B16.F10 cells accompanied by massive infiltration of both CD4+ T cells and CD8+ T cells into tumors. In cell transfer or depletion experiments we proved that both CD4+ T cells and CD8+ T cells induced by these vaccines play critical roles in the activation of antitumor immunity. Evidence of autoimmune reactions was not present in surviving mice that had rejected tumor cell challenges. We found that HSP105 was highly immunogenic in mice and that the HSP105 DNA vaccination induced antitumor immunity without causing autoimmunity. Therefore, HSP105 is an ideal tumor antigen that could be useful for immunotherapy or the prevention of various human tumors that overexpress HSP105, including colorectal cancer and melanoma.

Mouse homologue of a novel human oncofetal antigen, glypican-3, evokes T-cell-mediated tumor rejection without autoimmune reactions in mice.

PURPOSE AND EXPERIMENTAL DESIGN: We recently identified glypican-3 (GPC3) overexpressed specifically in human hepatocellular carcinoma, as based on cDNA microarray analysis of 23,040 genes, and we reported that GPC3 is a novel tumor marker for human hepatocellular carcinoma and melanoma. GPC3, expressed in almost all hepatocellular carcinomas and melanomas, but not in normal tissues except for placenta or fetal liver, is a candidate of ideal tumor antigen for immunotherapy. In this study, we attempted to identify a mouse GPC3 epitope for CTLs in BALB/c mice, and for this, we set up a preclinical study to investigate the usefulness of GPC3 as a target for cancer immunotherapy in vivo. RESULTS: We identified a mouse GPC3-derived and Kd- restricted CTL epitope peptide in BALB/c mice. Inoculation of this GPC3 peptide-specific CTL into s.c. Colon26 cancer cells transfected with mouse GPC3 gene (C26/GPC3) led to rejection of the tumor in vivo, and i.v. inoculation of these CTLs into sublethally irradiated mice markedly inhibited growth of an established s.c. tumor. Inoculation of bone marrow-derived dendritic cells pulsed with this peptide prevented the growth of s.c. and splenic C26/GPC3 accompanied with massive infiltration of CD8+ T cells into tumors. Evidence of autoimmune reactions was never observed in surviving mice that had rejected tumor cell challenges. CONCLUSIONS: We found the novel oncofetal protein GPC3 to be highly immunogenic in mice and elicited effective antitumor immunity with no evidence of autoimmunity. GPC3 is useful not only for diagnosis of hepatocellular carcinoma and melanoma but also for possible immunotherapy or prevention of these tumors.