Oleanolic Acid, a plant triterpenoid, significantly improves survival and function of islet allograft

BACKGROUND.: Oleanolic acid (OA) is a ubiquitous triterpenoid, with potent antioxidant and anti-inflammatory properties. Here, we tested whether these combined properties of OA can prevent nonimmunologic primary nonfunctioning and immunologic phenomena ascribed to graft rejection hence prolong islet allograft survival. METHODS.: Islet transplants were performed under kidney capsule of streptozotocin-induced diabetic C57BL/6 mice with BALB/c islets. Recipients were treated with 0.5 mg/day of OA intraperitoneally, and serum samples were collected once in 2 days and used for luminex, ELISA, and donor-specific antibody screening. Transplanted mice were killed at different time intervals to obtain splenocytes and kidney samples for ELISPOT, mixed leukocyte reaction, and immunohistochemical studies. RESULTS.: After transplantation, the decrement of blood glucose was significantly faster in mice receiving OA less than 2+/-1 days compared with untreated (4+/-2 days). OA prolonged survival of transplanted islets up to 23+/-3 days and reversed diabetes even with 250 islets. Treatment group showed increased serum interleukin (IL)-10 (twofold) and decreased inducible protein-10 and IL-4 (threefold) in luminex. Significantly reduced frequency of interferon-gamma (4.5-fold), IL-4 (3.5-fold), IL-2 (2.3-fold), and IL-17 (fourfold) producing T-cell populations were found in ELISPOT. OA-treated grafts had significant reduced and delayed infiltration of CD4+ and CD8+ T cells. OA also delayed donor-specific antibody generation up to 19 days after transplantation. Combined treatment with cyclosporine A, OA further prolonged the islet allograft survival to 34+/-3 days. CONCLUSIONS.: In conclusion, OA is an attractive, dietary nontoxic plant triterpenoid, which suppresses the production of proinflammatory cytokines and delays graft-specific immune responses to prolong islet allograft survival.

Generation of Janus alginate hydrogel particles with magnetic anisotropy for cell encapsulation

A microfluidic approach for fabrication of Janus hydrogel particles with magnetic anisotropy is demonstrated. Using this technique, cells and magnetic beads (MBs) can be separately embedded in one hydrogel particle to maintain optical performance, and reduce the contact between cells and magnetic beads (nano- or submicron-particles). Alginate cell capsules prepared by this method can be easily controlled and manipulated by external magnetic fields and require no specific surface modification. Bio-degradability and super-paramagnetic properties of these hydrogel particles were also demonstrated experimentally.

Heterogeneity of class I and class II MHC sequences in Schistosoma japonicum from different endemic regions in mainland China

The present study examined sequence variation in class I and class II major histocompatibility complex (MHC) genes among Schistosoma japonicum isolates from different endemic regions in mainland China and assessed the level of horizontal gene transfer and sequence similarity between parasites and their hosts. S. japonicum cercariae were used to infect male adult rabbits to obtain adult S. japonicum samples. A portion of the class I MHC gene (pMHC I) and class II MHC genes (pMHC II) were amplified separately from individual adult trematodes by polymerase chain reaction and sequenced. Among all the examined isolates of S. japonicum, sequence differences between male and female parasites were 0.0-26.6% for pMHC I and 0.0-7.0% for pMHC II. Sequence variations between male and female parasites among different geographical locations from the mountainous areas were 1.1-26.6% for pMHC I and 1.5-3.0% for pMHC II. Sequence variations between samples from Yunnan and those from Sichuan were 2.7-23.5% for pMHC I and 1.1-3.7% for pMHC II. In the lake/marshland areas, sequence variations between male and female parasites among different geographical locations were 0.0-25.0% for pMHC I and 0.0-7.0% for pMHC II. Sequence variations between S. japonicum isolates from mountainous areas, and those from lake/marshland areas were 0.0-26.1% for pMHC I and 0.4-6.1% for pMHC II. BLASTN analysis indicated that all the pMHC II sequences showed high homology to a portion of exon 3 in rabbit MHC class II DP beta gene with more than 89% similarity, and all the pMHC I sequences except isolates in Yunnan (Eryuan) revealed high homology to the portion of exon 2 in rabbit MHC I gene with more than 81% similarity. Phylogenetic analysis showed no specific clustering comprising parasites from single geographical or endemic regions, and the paired parasites were even found in different clusters. These results demonstrated that pMHC I and II of S. japonicum isolates in mainland China existed heterogeneity, but the pMHC I, II, or combined sequences were not suitable markers for examining genetic relationship among different isolates from endemic regions in mainland China.

The evaluation of whitening efficacy of cosmetic products using a human skin pigmentation spot model

BACKGROUND

To establish a pigmentation spot model on human skin and to assess whitening efficacy for whitening products by this established pigmentation spot model.

METHODS

Twenty subjects between 20 and 45 years old with skin phototype III or IV were selected. Three consecutive daily UV exposures were performed on buttocks of the subjects as follows: Day 1=1 minimal erythema dose (MED), Day 2=0.5 MED and Day 3=0.5 MED. After the first UV exposure, a selected whitening product was applied to the subjects twice a day on UV exposure area. The application of the whitening product to subjects on the exposed areas was continued till Day 27. CM2500d chromameter, Maxmeter MX18 and visual evaluation were used to assess changes of skin color.

RESULTS

A pigmentation spot model after UV exposure was established. The measurement of the pigment spot showed that L* value declined abruptly at Day 3 and then slowly reached to a lowest point at Day 6. L* value of the pigment spot almost remained at the same level until Day 20, thereafter increased slowly. The a* value showed an abrupt increase at Day 3 and slowly reached to a maximal level at Day 6. The a* value slowly declined toward its baseline level. Likewise, the erythema index also increased significantly at Day 3, and reached to a maximal level at Day 6 and then slowly declined. However, L*, a* and erythema indices did not return to their baseline levels during the 27-day period of this study. On the other hand, b* value started to increase from Day 3 and such increase was observed continuously to Day 27. Melanin index also showed a slow increase during the first 3 days. It started to increase rapidly from Day 3 and a to maximal level at Day 9 and maintain at a plateau till Day 27 (with an exception at Day 13). To assess the whitening product by this pigmentation spot model, DeltaL, Deltab*, and DeltaM values were analyzed. It showed that absolute DeltaL value and Deltab*value of whitening products were lower than those values of the vehicle of the whitening product at each checkpoint, while DeltaM value of the whitening product was lower only at Day 9 and Day 20, although no statistically significant differences was found. The visual results also strongly supported that the whitening product enhanced the decrease of pigmentation.

CONCLUSION

This study showed that repeated UV exposure was able to induce a long extensive period of pigment formation. The resulted pigmentation spot was able to maintain at an elevated level till Day 20. Clinical subjective evaluations together with combined objective instrument measurements were still important to assess whitening and spot-removing ability of a material due to the instrument limitation for color differentiations. This kind of pigmentation spot model can be used to assess whitening efficacy for whitening or spot-removing products. In addition, the combinations of subjective and objective methods were able to serve as advisable references to assess the whitening efficacy of products.

Comparison of native E. coli and PEG asparaginase pharmacokinetics and pharmacodynamics in pediatric acute lymphoblastic leukemia

Asparaginase (ASP) is used routinely in frontline clinical trials for the treatment of childhood acute lymphoblastic leukemia (ALL). The goals of this study were to assess the pharmacokinetics and pharmacodynamics of ASP and to mathematically model the dynamics between ASP and asparagine (ASN) in relapsed ALL. Forty children were randomized to receive either native or polyethylene glycolated (PEG) Escherichia coli ASP during reinduction therapy. Serial plasma ASP and ASN, cerebrospinal fluid (CSF) ASN, and serum anti-ASP antibody samples were collected. The ASP clearance was higher (P = 0.001) for native vs. PEG ASP. Patients with antibodies to PEG ASP had faster PEG ASP clearance (P = 0.004) than did antibody-negative patients. Patients who were positive for antibodies had higher CSF ASN concentrations than did those who were negative (P = 0.04). The modeling suggests that by modifying dosages, comparable ASN depletion is achievable with both preparations. At relapse, there were significant pharmacokinetic and pharmacodynamic differences attributable to ASP preparation and antibody status.

Insulin receptor substrate 2 plays important roles in 17beta-estradiol-induced bone formation

BACKGROUND

Discovering the mechanisms of the estrogen effects on the osteoblasts is very important for the development of new agents which have the clear-cut beneficial effects of estrogen while free of adverse effect.

AIM

The aim of this study was to investigate the differential gene expression of 17beta-estradiol (E2)-treated osteoblast-like cells, and the effect of E2 on the insulin receptor substrate 2 (IRS- 2) expression in human cultured osteoblast-like cells and the osteoblasts of ovariectomized (OVX) rats.

MATERIAL AND METHODS

The differential gene expression of E2-treated osteoblast- like cells was analyzed by cytokine expression array and validated by RT-PCR and Western blot analysis. The protein expression and phosphorylation of one of the differentially expressed gene, IRS-2, treated at different times with E2 were analyzed. The Sprague-Dawley rats were ovariectomized and then treated with E2, the IRS-2 expression was analyzed by immunohistochemistry analysis.

RESULTS

E2 upregulated the mRNA expression of IRS-2, bone morphogenetic protein 9, and connective tissue growth factor expression, down-regulated the mRNA expression of matrix metalloproteinase 15 and some tumor suppressor genes. Peak expression of IRS-2 was observed at 12-24 h of treatment by 10-8M E2. E2 can also increase the phosphorylation of IRS-2. The IRS-2 expression was down-regulated in the osteoblasts and bone marrow cells of the OVX rats, which had lower bone mineral density (BMD) than the normal rats. However, both BMD and IRS-2 expression can be rescued by 10-8M E2 in the OVX rats.

CONCLUSION

IRS-2 in osteoblast is up-regulated by E2 and plays important roles in the estrogen- induced bone formation.

Impact of hypertension on health-related quality of life in a population-based study in Shanghai, China

OBJECTIVES

The purpose of this study was to examine the relationship between hypertension and health-related quality of life (HRQL) in a general representative Chinese population, and to explore the impacts of comorbidity on people with hypertension.

STUDY DESIGN

Population-based cross-sectional survey.

METHODS

A self-administered questionnaire survey including demographic questions and the Mandarin version of 36-item Short Form (SF-36) was conducted in a general population in Shanghai, China. In total, 1034 subjects participated. The SF-36 dimension scores of hypertensive subjects were compared with those of normotensive subjects. Independent association of hypertension with each quality-of-life domain was analysed using a multiple linear regression model, so were the effects of comorbidity on the HRQL of hypertensive subjects.

RESULTS

Nine hundred and nineteen respondents were included in the analysis, and 16.97% reported hypertension. Respondents with hypertension scored lower than those without hypertension in at least five SF-36 dimensions. The dimension of role limitations due to physical problems was the most affected, whereas the mental health dimension was the least affected. Hypertensive subjects with comorbidity experienced lower SF-36 scores than hypertensive subjects without comorbidity.

CONCLUSIONS

Hypertension markedly impairs quality of life in terms of both physical and mental health. Comorbidity further deteriorates HRQL among people with hypertension. The findings suggest that people with hypertension represent a vulnerable population, and it is important to prevent and treat comorbidity of hypertension.

Comparison of Hyperbolic and Constant Width Simultaneous Confidence Bands in Multiple Linear Regression under MVCS Criterion

A simultaneous confidence band provides useful information on the plausible range of the unknown regression model, and different confidence bands can often be constructed for the same regression model. For a simple regression line, it is proposed in Liu and Hayter (2007) to use the area of the confidence set that corresponds to a confidence band as an optimality criterion in comparison of confidence bands; the smaller is the area of the confidence set, the better is the corresponding confidence band. This minimum area confidence set (MACS) criterion can clearly be generalized to the minimum volume confidence set (MVCS) criterion in study of confidence bands for a multiple linear regression model. In this paper the hyperbolic and constant width confidence bands for a multiple linear regression model over a particular ellipsoidal region of the predictor variables are compared under the MVCS criterion. It is observed that whether one band is better than the other depends on the magnitude of one particular angle that determines the size of the predictor variable region. When the angle and so the size of the predictor variable region is small, the constant width band is better than the hyperbolic band but only marginally. When the angle and so the size of the predictor variable region is large the hyperbolic band can be substantially better than the constant width band.

Infusion of mesenchymal stem cells and rapamycin synergize to attenuate alloimmune responses and promote cardiac allograft tolerance

The inherent immunosuppressive properties and low immunogenicity of mesenchymal stems cells (MSCs) suggested their therapeutic potential in transplantation. We investigated whether MSCs could prolong allograft survival. Treatment involving infusion of MSCs into BALB/c recipients 24 hours after receiving a heart allograft from a C57BL/6 donor significantly abated rejection and doubled graft mean survival time compared to untreated recipients. Furthermore, combination therapy of MSCs and low-dose Rapamycin (Rapa) achieved long-term heart graft survival (>100 days) with normal histology. The treated recipients readily accepted donor skin grafts but rejected third-party skin grafts, indicating the establishment of tolerance. Tolerant recipients exhibited neither intragraft nor circulating antidonor antibodies, but demonstrated significantly high frequencies of both tolerogenic dendritic cells (Tol-DCs) and CD4(+)CD25(+)Foxp3(+)T cells in the spleens. Infusion of GFP(+)C57BL/6-MSCs in combination with Rapa revealed that the GFP-MSCs accumulated in the lymphoid organs and grafts of tolerant recipients. Thus, engraftment of infused MSCs within the recipient's lymphoid organs and allograft appeared to be instrumental in the induction of allograft-specific tolerance when administered in combination with a subtherapeutic dose of Rapamycin. This study supports the clinical applicability of MSCs in transplantation.

Effects of adenovirus-mediated gene transfer of ICOSIg and CTLA4Ig fusion protein on experimental autoimmune myocarditis

OBJECTIVE

To explore the therapeutic alliance effects of adenovirus vector-mediated gene transfer of ICOSIg and CTLA4Ig fusion protein on experimental autoimmune myocarditis (EAM).

METHODS

Expression vector pAdeno-CTLA4Ig and pAdeno-ICOSIg was constructed and transfected into HEK293 cells. Adenovirus expresses CTLA4Ig and ICOSIg was produced. Ad-CMV-GFP was used as controls. EAM was induced in Lewis rats by injection of procine cardiac myosin. All the immunized rats were divided into four groups. Group A (n = 15) received adenovirus containing CTLA4Ig and ICOSIg from day 14-28; group B (n = 15), group C (n = 15) and group D (n = 15) received adenovirus containing CTLA4Ig, ICOSIg and GFP, respectively. Group E (n = 10) was normal controls never received immunization. On day 28, all the rats were killed after echocardiography examination. Histopathological examination was used to observe inflammation in the myocardium. Western blot was used to detect CTLA4, ICOS, ICOSL and competitive RT-PCR for B7-1, B7-2 expression. T lymphocyte proliferation assay was performed and ELISPOT was used to detect the Th1 and Th2 production.

RESULTS

Alliance application of CTLA4Ig and ICOSIg exerts therapeutic effects on EAM. After a treatment duration of 14 days, cardiac function and myocardial inflammation improved significantly compared to group D. Expression of CTLA-4, ICOS and ICOSL, B7-1 was statistically decreased in group A, B and C compared with group D. T-cell proliferation was inhibited by costimulatory blockade in a dose-dependent style. ICOSIg blockade significantly augments IL-4 and IL-10 production while diminished IFN-gamma production.

CONCLUSIONS

Blockade of costimulatory pathway with alliance therapy of CTLA4Ig and ICOSIg alleviated autoimmune damage in EAM and improved cardiac function. The mechanisms may be downregulation of costimulatory molecules and anti-inflammation.

High glucose attenuates insulin-induced VEGF expression in bovine retinal microvascular endothelial cells

PURPOSE

To investigate the effect of high glucose on insulin-induced vascular endothelial growth factor (VEGF) expression in bovine retinal microvascular endothelial cells (BRECs) and to probe into related mechanisms.

METHODS

BRECs were isolated as primary cultures and identified by immunostaining. Passage cells were initially exposed to normal (5 mM) or high glucose (30 mM) for 3 days, and equimolar L-glucose was supplemented for osmotic equation. BRECs were then treated with 100 nM insulin for 24 h or not, and cells were prepared for the determination of VEGF mRNA expression by real-time PCR. VEGF protein was determined by human umbilical vein endothelial cell proliferation assay, immunofluorescence, and ELISA. BRECs were treated with 5 or 30 mM glucose for 3 days and then cells cultured with 5 mM glucose were exposed to the PI3-K inhibitor wortmannin (100 nM), the P42/44 mitogen-activated protein kinase (MAPK) inhibitor U0126 (50 microM), or to the protein kinase C (PKC) inhibitor GF109203X (2 microM) 1 h before addition of 100 nM insulin. Twenty-four hours after incubation with insulin, the cells were subjected to real-time PCR and ELISA analyses.

RESULTS

Insulin or high glucose alone markedly increased VEGF mRNA and protein levels in BRECs (P<0.05, two-way ANOVA). However, the combination of insulin and high glucose displayed a weaker effect in promoting VEGF expression than did insulin alone (P<0.05, t-test). Pretreatment of cells with PI3-K inhibitor significantly (P<0.05, one-way ANOVA) suppressed the insulin-induced VEGF expression; neither pretreatment with the PKC inhibitor nor with the P42/p44 MAPK inhibitor showed an effect on the expression of VEGF at the mRNA or protein level (P>0.05, one-way ANOVA).

CONCLUSIONS

Both insulin and high glucose can markedly increase VEGF expression in BRECs at the mRNA and protein level. We propose that insulin may upregulate VEGF expression through the PI3-K signalling pathway in BRECs, and high glucose may attenuate insulin-induced VEGF expression by impairing PI3-K signalling pathways.

Expression of cathepsin L in nasopharyngeal carcinoma and its clinical significance

AIM

To study the expression of cathepsin L in nasopharyngeal carcinoma (NPC), and analyze its relationship with clinicopathologic factors.

METHODS

The expression of cathepsin L was determined immunohistochemically in NPC, adjacent normal nasopharyngeal tissues and metastatic cervical lymph nodes. The correlation between its protein expression and clinicopathologic parameters as well as with long term follow-up data in NPC was analyzed.

RESULTS

The protein of cathepsin L was overexpressed in 47% primary tumor tissues, and in 89% metastatic cervical lymph node samples. Overexpression of cathepsin L was found to correlate with lymph node metastasis ( P = 0.04) and distant metastasis ( P = 0.01), and marginally with clinical stage and T classification, but not with patient age, gender and histological classification of tumor. Patients with overexpression of cathepsin L in tumor tissue had worse 5-year survival than those without such expression pattern ( P = 0.033). Multivariate survival analysis showed that cathepsin L protein expression level had a marginal significant correlation with prognosis of NPC.

CONCLUSION

Cathepsin L is a potential biomarker for prognosis of NPC and contributes to NPC metastasis.

Circulating tumor and endothelial cells as pharmacodynamic biomarkers in a phase I clinical trial of intravenous bevacizumab in combination with escalating doses of oral cediranib for patients with advanced malignancies

3525

Background: Rare circulating tumor cells (CTCs) and endothelial cells (CECs) offer a feasible approach for studying the pharmacodynamic effects of investigational agents. We investigated the effects of bevacizumab (B) and cediranib (C) on inhibition of the VEGFR pathway and correlated these changes with dose and clinical response. Methods: Peripheral blood was obtained at baseline, 24hrs and at C2D26–30 post-treatment from patients (n=14) undergoing dose escalation of intravenous B and oral C. CTCs and CECs (CD31+ or CD105+) were isolated and immunofluorescently stained. Laser scanning cytometry (LSC) was used to quantify phosphorylated and total-VEGFR2 (pVEGFR2/VEGFR2), pERK/ERK, and apoptosis in each phenotype. Changes in each biomarker were correlated with partial response (PR) or stable disease and progression > 2 months, evaluated using RECIST. Results: Overall, immature CECs (CD105+) enumerated by CellSearch™ revealed a dose-dependent significant decrease (p=0.0001). A 3-fold induction in apoptosis was observed at 24 hrs compared to baseline in the CD105+ CECs. Mature CD31+ cells assessed for VEGFR2 activity revealed an 83% and 1.9% significant (p=0.019) inhibition in pVEGFR2 expression at low (B;3mg/kg) and high (B;5mg/kg) doses, respectively. In the non-responders, mature CECs revealed a dose-dependent significant increase (-6.8% to 63%;p=0.031) in pERK/ERK expression levels. No significant changes were observed in CTC enumeration by CellSearch™. LSC-mediated CTC enumeration revealed a 4.77 % and 2.33% increase in CTCs following treatment in the non- responders and responder (p=0.809), respectively. Analysis of pVEGFR2 in CTCs revealed a 58% inhibition in the responder versus a 163% increase in expression in the non-responders (p=0.63). Conclusions: Inhibition of pVEGFR2 and induction of apoptosis in CECs confirmed the target therapy. An increase in CD105+ CECs is consistent with the hypothesis that anti-angiogenic efficacy induces endothelial cell shedding. Assessment of CECs indicates that B and C are more biologically active at lower doses, and resistance may be attributed to ERK activity. Support: UO1 CA062461 (RK)

No significant financial relationships to disclose.

Effect of lenalidomide on the antiproliferative effect of gemcitabine against pancreatic tumor cells and on immune-mediated pancreatic cancer cell death

e14635

Background: Lenalidomide is an immunomodulatory and anti-angiogenic agent that has demonstrated activity against a range of hematological malignancies. Despite evidence of direct anti-proliferative activity against hematological cells in vitro, there is no evidence of single agent direct activity against solid tumor cells in vitro. To take advantage of its known immune-enhancing properties alongside direct anti-tumor agents, lenalidomide is being advanced in solid tumor indications in combination with other agents. There are few data regarding the combination of lenalidomide and standard of care chemotherapeutic agents, such as gemcitabine. Methods: Here, we assess the effects of lenalidomide alone, and in combination with gemcitabine, on pancreatic cancer cell growth and survival, and the ability of lenalidomide to enhance the ability of human PBMC to kill allogeneic pancreatic tumor cells (BxPC3, PANC-1 and MiaPaCa) in a PBMC:tumor cell co-culture model. Results: Lenalidomide alone had no effect on the proliferation of pancreatic cancer cells (BxPC-3 and Panc-1) whereas gemcitabine had moderate anti-proliferative activity. With combination therapy there was clear synergistic enhancement of anti-proliferative activity in both cell lines and additive effects were observed in a BxPC-3 xenograft mouse model of pancreatic cancer. About 20% of tumor cells were sensitive to immune-mediated cell death and, for BxPC3, this was increased significantly in the presence of lenalidomide. Lenalidomide significantly and dose-dependently enhanced immune-mediated killing (both T and NK cells are required for tumor cell killing in this model). For PANC-1 and MiaPaCa, immune-mediated killing was also increased by lenalidomide, albeit non-significantly. Conclusions: These results suggest that, in addition to anti-angiogenic and other effects within the tumor microenvironment, lenalidomide may act as an immune adjuvant to enhance the recognition and apoptosis of tumor cells by host T and NK cells. These studies support the potential utility of lenalidomide in combination with chemotherapeutic agents, gemcitabine in particular, in the treatment of patients with solid tumors including pancreatic cancer.

[Table: see text]

Gemcitabine in combination with intraperitoneal cisplatin in advanced hepatobiliary cancers

e15666

Background: Standard chemotherapy for advanced hepatobiliary cancers remains undefined. This study was to observe the therapeutic effect of gemcitabine combined with intraperitoneal cisplatin for the treatment of advanced hepatobiliary cancers and analyze their toxicities. Methods: Patients with measurable hepatobiliary cancers were unrandomized into gemcitabine (GEM) + cisplatin (DDP) (GEM group) and epirubicin (EPI) + DDP (EPI group). GEM was used intravenously by infusion for 30 min with the dose to 1,000 mg/m2 on day 1 and 8; cisplatin was infused intraperitoneal with a dose of 25mg/m2 on day1, 3 and 5. Twenty-one days counted as one cycle. After 2 cycles, treatment efficacy and adverse events were evaluated according to WHO criteria. Results: A total of 76 patients were enrolled from May 2004 to May 2006, with 30 patients for EPI group and 46 patients for GEM group, and all the patients were eligible for effectiveness analysis. Among GEM group patients, there was no complete response. The partial response rate was 32.61% and clinical benefit response (CR+ PR +SD) was 67.39%. All those data mentioned above were significantly higher than that of EPI group. The main adverse re-ction was hematologic toxicity, while nonhematologic toxicity was mild. Conclusions: This study demonstrated that combination gemcitabine with intraperitoneal infusion of cisplatin was an effective and safety treatment for the patients with advanced hepatobiliary cancers.

No significant financial relationships to disclose.

Breast cancer patients stratification by microarray-based gene expression profiling from FFPET samples

e22041

Background: Microarrays have been used to monitor global genes expression and have aided the identification of novel biomarkers for patients stratification and drug response prediction . To date there has been limited application of microarray- based gene expression analysis to formalin fixed paraffin embedded tissues (FFPET). FFPE tissues are the most commonly available clinical samples with documented clinical information for retrospective clinical analysis. However, FFPET RNA has proven to be an obstacle for microarray analysis because of low yield and compromised RNA integrity. Methods: Using a novel RNA amplification method, Single Primer Isothermal Amplification (SPIA, NuGEN Inc, San Carlos, CA), we amplified FFPET RNA, hybridized amplified, and labeled cDNA onto Affymetrix HG U133plus2 GeneChips. Results: We found that SPIA amplification successfully overcomes the problems of poor quality of FFPET RNA, and produced informative biological data. Comparing the gene expression data from 5 different types of FFPET archival cancer samples (breast, lung, ovarian, colon, and melanoma), we demonstrated that gene expression signatures clearly distinguish the tissue of origin. Further, from an analysis of 91 FFPET samples comprised of ER+, HER2+, triple negative breast cancer patients, and normal breast tissue, we have identified a 103 gene signature that distinguishes the intrinsic sub-types of breast cancer. Finally, the accuracy of gene expression measured by microarray was verified by real time PCR quantitation of the ERBB2 gene, resulting in a significant correlation (R = 0.88). Conclusions: We have demonstrated the feasibility of global gene expression profiling using RNA extracted from FFPET and have shown that a gene expression signature can stratify patient samples into different subtypes of disease. This study paves the way to identify novel molecular biomarkers for disease stratification and therapy response from archival FFPET samples, leading to the goals of personalized medicine.

No significant financial relationships to disclose.