Deficiency in TLR2 but not in TLR4 impairs dendritic cells derived IL-10 responses to schistosome antigens

The purpose of this study was to observe the diverse functions of Toll-like receptors (TLRs) in responses to specific schistosome antigens. Bone marrow-derived dendritic cells (BMDCs) from TLR2-deficient (TLR2(-/-)) or TLR4-deficient (TLR4(-/-)) mice were activated with soluble schistosomule antigen (SSA) or soluble egg antigen (SEA). TLR2 mRNA expression was significantly increased in B6 BMDCs following SEA stimulation. TLR2-deficient BMDCs showed enhanced MHCII expression following SSA and SEA stimulation. TLR2-deficient but not TLR4-deficient BMDC failed to produce IL-12p70 and IL-10 in response to schistosome antigens. TLR2-deficient BMDCs induced a stronger CD4(+) T cell proliferative response. IL-4 and IL-10 expression was inhibited in CD4(+) T cells primed with TLR2-deficient BMDCs, while enhanced in TLR4-deficient BMDCs-primed CD4(+) T cells. These results suggest that TLR2 is essential for the establishment of the DC production of IL-12p70 and IL-10.

Ontogenesis of Ap-2γ expression in rat testes

Searching for useful markers of spermatogonial stem cells and their differentiation, we used rat testes from ages representing different stages of testicular maturation to investigate the expression profile of transcription factor activation protein-2γ (Ap-2γ). The immunohistochemical and immunocytochemical evaluation using Ap-2γ and promyelocytic leukemia zinc finger in combination with sorting of CD9 and CD90 positive cells (undifferentiated spermatogonia) by fluorescence-activated cell sorting was performed. Our experiments revealed that Ap-2γ is detectable in testes of late fetal age and up to 60 days postnatally and is expressed in gonocytes and spermatogonia from late fetal age throughout all maturational stages. Restricted nuclear expression of Ap-2γ to undifferentiated male germ cells was verified by coexpression of Ap-2γ with promyelocytic leukemia zinc finger in sections of paraffin-embedded testes as well as in cells sorted positive for CD9 and CD90 expression. Our study demonstrated clearly that nuclear expression of Ap-2γ is a useful marker for identifying undifferentiated male germ cells, although its functional role is yet to be fully explored.

Real-time detection of auditory steady-state responses

Detection of the auditory steady-state responses (ASSRs) is a difficult task, its main technical impediment is no other than the excessively lengthy recording time required for the estimation process due to the extremely low signal-to-noise ratio (SNR). To improve the detection rate of ASSRs, a new observer-based real-time ASSR detector is derived as an alternate solution to the existing methods. The ASSR detector has a simple structure, and provides fast and reliable signal detection. Simulation and experimental recorded data were used to evaluate the performances of the proposed approach. Compared with the conventional methods, the proposed method requires shorter recording time which could be proven as a valuable hearing screening or diagnostic tool.

Promoter Methylation and Phosphorylation Status of PTEN in Taiwanese Breast Cancer

Background: The PTEN (phosphatase and tensin homolog deleted on chromosome Ten) gene is a novel candidate of tumor suppressor that plays an important role in cell cycle regulation and apoptosis by modulating protein kinase-B/AKT activity. In western breast cancer population, PTEN downregulation is frequently associated with high-grade tumor, distant metastases and poorer disease-free survival. It is also noted that the methylation of the PTEN promoter results in PTEN inactivation in a subset of breast cancers. Taiwan is the low-incidence area of breast cancer. However, breast cancer has been jumped to the first place in the incidence of female malignancies in the past 3 years. Hence, we aim to explore the potential role of PTEN in Taiwanese breast cancer.Material and Method: Firstly, we used tissue microarrays containing 192 specimens (PTEN) and 193 samples (p-PTEN) from the Department of Pathology, Kaohsiung Medical University to analyze the expression patterns of PTEN and p-PTEN (Ser380/Thr382/Thr383) protein by immunohistochemistry (anti-PTEN antibody, A2B1, and anti-p-PTEN R, Santa Cruz). Clinical data, such as stage, grade, recurrence, lymph-node metastasis, and patient's age, tumor-specific survival (in months) and others were included in our statistic analysis. The genomic DNA (1 μg) obtained from 318 fresh specimens containing 159 matched cancer and non-cancer tissues were treated with sodium bisulfite for 16 hours and purified using methylation-specific PCR (MSP) kit (Millipore). Separate primers were used for amplification of methylated and unmethylated promoter regions. Primers that amplified a region of the promoter specific to PTEN gene but not the PTEN pseudogene were used. Primers used to amplify the methylated PTEN promoter were 5'-GTATTTCGAGTAAAGGAAGAAGACG-3' and 5'-GATAAAAAACTACAACC CAACGAA-3'; those used to amplify the unmethylated promoter were 5'- TATTTTGAGTA AAGGAAGAAGATGA-3' and 5'-CAATAAAAAACTACAACCCAACAAA-3'.Results: Our results showed that an increased nuclear expression of PTEN was positively correlated with an increased tumor staging (p=0.010). Furthermore, an increased p-PTEN expression in the cytoplasm was inversely correlated with tumor staging (p=0.003), while the decreased expression of p-PTEN in the nucleus was significantly correlated with positive recurrence rate (p=0.009) and metastasis to lymph node (p=0.033). Notably, the expression level of p-PTEN was positively correlated with that of PTEN. We also observed that the methylation of PTEN promoter was increased in 70% of breast cancer tissues as compared with the matched non-cancer breast tissues. Moreover, the increased methylation of PTEN promoter was positively correlated with tumor grade (p=0.037).Discussion: Taken together, our results suggest that an altered PTEN expression through methylation or phosphorylation may have potential roles in Taiwanese breast cancer. The underlying mechanism requires further investigation.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4060.

Efficacy and Safety Data of Taiwan Breast Cancer Patients Enrolled in the Lapatinib Expanded Access Program (LEAP)

Background: LEAP is a single-arm, open-label, expanded access study of lapatinib in combination with capecitabine in 42 countries. The primary objective of LEAP was to provide patients with pre-approval access to lapatinib based on positive clinical data from a pivotal Phase III trial.Methods: Enrolled patients had locally advanced or HER2 positive metastatic breast cancer (MBC), progressive disease (PD, by modified RECIST) following prior therapy with anthracycline-, taxane-, and trastuzumab-containing regimens, including some patients previously treated with capecitabine, and were ineligible for ongoing lapatinib trials. Patients received lapatinib (1250 mg/day) and capecitabine (2000 mg/m2/day, days 1-14, every 21 days). Baseline characteristics, including prior therapies, were collected. Response was assessed using RECIST criteria.Results: From Mar 2007 to Sep 2008, 238 patients were enrolled at 10 centers in Taiwan. At the 11 June 2009 data cut-off, data were collected and analyzed for 166 patients. Patients received an average of 5 prior cytotoxic therapies, including trastuzumab and capecitabine.Of 166 patients, 3 (2%) had complete response, 49 (30%) had partial response, 62 (37%) had stable disease, 42 (25%) had PD, and 10 (6%) were unknown. The median duration of treatment was 5.5 mo and the median time to progression was 5.3 mo, respectively. Per protocol, only serious adverse events (SAEs) were reported. Thirty SAEs were reported for 238 patients; 6 (20%) were considered treatment-related by investigators, were not fatal, and included stomatitis (2), vomiting (2), diarrhea (1), and cellulitis (1). As of 11 June 2009, 66 (40%) patients were alive and 149 withdrew from LEAP, the majority (85%) because of progressive disease.Conclusion: Although data were collected retrospectively via case report forms, these results reflect the real world setting in Taiwan for the treatment of erbB2+ MBC patients and confirms that lapatinib, in combination with capecitabine, demonstrates efficacy in this patient population including those who are heavily pretreated.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5093.

Gefitinib versus platinum contained doublet chemotherapy in chemotherapy-naive patients with stage IIIb or IV non-small cell lung cancer of adenocarcinoma histology: A retrospective case control study

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Background: The results of the ISEL study in non-small cell lung cancer (NSCLC) suggest greater benefit of gefitinib among Asian patients and non-smokers compared with the overall trial population. Methods: We conducted a retrospective case-control study to compare outcomes for gefitinib versus platinum doublet chemotherapy as first line treatment in selected NSCLC patients (stage IIIB/IV adenocarcinoma, PS 0–2). Patient receiving platinum chemotherapy were selected on the basis of disease stage (IIIB or IV), gender, smoking history, WHO performance status (PS) (0–1, or 2) and age (< 60ys or ≥ 60ys) being matched to patients receiving gefitinib. Gefitinib and chemotherapy arm patients were selected by 1:2 ratio in order to increase statistical power. The study was approved by local institute review board. Results: 99 chemo-naïve adenocarcinoma patients treated in our institute from January 2006 to December 2007 were collected: 33 received gefitinib and 66 received chemotherapy. The baseline characteristics are listed in table 1 . The median duration of follow-up was 10 months. Patients receiving gefitinib experienced significantly higher ORR and DCR, and prolonged PFS ( table 1 ). Patients receiving chemotherapy experienced more frequent grade 3–4 neutropenia (42.4% vs 0%), thrombocytopenia (21.2% Vs 0%), febrile neutropenia (7.5% vs 0%) and nausea (24.2% vs 3.0%). The most commonly recorded adverse events in the gefitinib arm were rash/acne (9.1%), diarrhea (3.0%), nausea (3.0%) and anemia (3.0%). Conclusions: The limitations of case-control studies are acknowledged, yet these results were supported by IPASS. Gefitinib as first-line treatment confers clinically relevant benefit in Asian NSCLC patients with adenocarcinoma histology versus platinum based chemotherapy.

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Modulation of immune response with cytotoxic T-lymphocyte-associated antigen 4 immunoglobulin-induced anergic T cells in chronic idiopathic thrombocytopenic purpura

BACKGROUND

Platelet glycoprotein (GP)-reactive CD4+ T cells are essential for the stimulation and maintenance of antiplatelet autoantibody production in chronic idiopathic thrombocytopenic purpura (ITP). Blocking costimulatory signals could result in platelet-specific T-cell anergy.

METHODS

GP-specific CD4+ T cells from patients with ITP were made anergic using cytotoxic T-lymphocyte-associated antigen 4 immunoglobulin (CTLA4-Ig). The CTLA4-Ig-induced GP-specific anergic T cells were investigated for their inhibitory function on GP-reactive T-cell proliferation and antibody production with in vitro culture systems. To further analyze their tolerizing mechanisms, we cocultured GP-anergic T cells with dendritic cells (DCs) from patients with ITP.

RESULTS

Our studies demonstrated that the anergized GP-specific T cells have profound effects on both GP-specific T-cell proliferation and antibody production. These anergic T cells exerted their suppressive effects mainly in a cell contact-dependent manner, and they were not constitutively suppressive but required specific antigen stimulation to make DCs tolerogenic. The anergic T-cell-modulated DCs could induce the autoreactive T cells to be tolerant, and this effect was not restricted to T cells of the same specificity.

CONCLUSION

Our studies demonstrate the efficacy of CTLA4-Ig in suppressing the pathologic autoimmune responses in ITP. These findings provide new insights into the underlying mechanisms of anergy induction in chronic ITP.