Genetic variants in angiogenesis pathway associated with clinical outcome in NSCLC patients (pts) treated with bevacizumab in combination with carboplatin and paclitaxel: Subset pharmacogenetic analysis of ECOG 4599

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Background: E4599 was a randomized phase III study which demonstrated a survival advantage in advanced NSCLC pts treated with bevacizumab (bev) + carboplatin/paclitaxel (BPC) versus carboplatin/paclitaxel alone (PC). Recent studies have shown certain germline polymorphisms (SNPs) are associated with clinical outcome in advanced breast cancer pts treated with paclitaxel plus bev and in advanced colorectal cancer pts treated with first line 5-FU or capecitabine in combination with oxaliplatin and bev. A study also found 2 SNPs in WNK1 gene were associated with bev-induced hypertension. We tested the hypothesis that SNPs involved in angiogenesis pathway (VEGF, EGF, EGFR, IL-8, KDR, ICAM1, FGFR4), DNA repair pathway (ERCC1, XPD, XRCC1, GSTP1) and WNK1 may predict clinical outcome in a subset of pts enrolled on E4599. Methods: Of 878 pts enrolled, samples from 146 pts were available for the current pharmacogenetic study and only 133 of the samples (67 PC, 66 BPC) came from eligible pts. PCR-RFLP assays were performed on genomic DNA extracted from sera of pts. The Kaplan-Meier method was used to estimate time-to-event distributions. Multivariable Cox models adjusted for gender, PS, stage, adrenal, liver and bone mets were separately fitted for each SNP to obtain estimates of hazard ratios. Results: Median OS for the 133 patients was 10.3 mos (8.2–15.6) for PC and 13.0 mos (10.2–16.6) for BPC. Median PFS was 4.6 mos (3.6–5.6) for PC & 6.5 mos (5.4–8.3) for BPC. Pts with mutant homozygote CC genotype for ICAM1 T469C had significantly higher tumor response rate (39%) than heterozygote CT (13%) and homozygote TT (20%) genotype (Fisher's test, p=0.04). Tests for whether treatment effect differs by genotype via interaction terms in the Cox models were statistically significant (p<0.05) for VEGF G-634C, ICAM1 T469C and WNK1-rs11064560 for OS, and for ICAM1 T469C, EGF A-61G and CXCR2 C785T for PFS. Conclusions: Although exploratory, our preliminary results suggest germline SNPs in angiogenesis pathway may predict response, PFS and OS in NSCLC pts treated with BPC. Prospective trials based on these correlative studies are warranted.

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VEGF and VEGFR1 gene expression levels and tumor recurrence in adjuvant colon cancer

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Background: Tumor recurrence after curative resection is still a major problem in the management of adjuvant colon cancer, with recurrence rate approximately 30–40%. Identifying molecular markers for tumor recurrence is critical for successfully selecting patients who are more likely to benefit from adjuvant chemotherapy. Our group previously showed that angiogenesis gene polymorphisms (VEGF and IL-8) may associated with tumor recurrence in adjuvant colon cancer (Lurje Ann Oncol, 2008). Here we tested the hypothesis whether gene expression levels of angiogenesis pathway (COX-2, EGFR, VEGF, VEGFR1, VEGFR2 and IL-8) could also predict the risk of tumor recurrence in stage II and III colon cancer patients treated with adjuvant chemotherapy. Methods: Tissue samples from 140 adjuvant colon cancer patients (69 females and 71 males with a median age of 59 years; range=28–86) were available for gene expression assays. These tissue samples were obtained at the University of Southern California/Norris Comprehensive Cancer Center (USC/NCCC) and LAC+USC medical center between 1999 and 2006. Sixty-three patients had stage II and 77 had stage III colon cancer. The median follow-up was 5.4 years (range=2.0–16.8). 51 of 140 patients (36.4%) developed tumor recurrence with a 5-year probability of 0.28 ± 0.06 for stage II and 0.40 ± 0.06 for stage III colon cancer patients. mRNA was extracted from laser-capture-microdissected tumor tissue. After cDNA was prepared by reverse transcription, quantitation of the candidate genes and an internal reference gene (ß-actin) was performed using a fluorescence-based real-time detection method (TaqMan). Results: We found VEGF and VEGFR1 gene expression levels independently significantly associated with time to tumor recurrence in adjuvant colon cancer patients. Patients with lower VEGF gene expression and lower VEGFR1 gene expression levels had significantly longer time to tumor recurrence compared to those with higher VEGF and higher VEGFR1 gene expression levels (p<0.05, log-rank test). Conclusions: VEGF and VEGFR1 gene expression levels may predict tumor recurrence risk in adjuvant colon cancer patients. Our exploratory data warrant future confirmatory trial.

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CXCR4-CXCL12 axis: Pivotal role as a metastatic mediator in small cell sarcoma

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Background: The chemokine CXCL12, and its receptor CXCR4, are expressed in over 23 different types of cancers, and have been associated with the metastatic phenotype and inferior clinical outcomes. Given the poor prognosis after failure of front-line therapy for patients with metastatic Ewing's sarcoma (EWS) and rhabdomyosarcoma (RMS), we examined the functional role of CXCR4 in these small cell sarcoma in vitro. Methods: Human EWS and RMS cell lines and tissue were used to study CXCR4 expression and activation. Immunoblotting techniques were used to evaluate CXCR4 activation and inhibition. Cell viability, cell cycle, apoptosis, chemosensitivity, migration, and invasion assays were utilized to assess the effects of the small peptide CXCR4 antagonist, CTCE-9908 (Chemokine Therapeutics) on cultured cells. Results: CXCR4 was highly expressed on 46 % of human RMS tumor samples. CXCR4 underwent phosphorylation after stimulation with CXCL12 in EWS and RMS cell lines with downstream activation of Akt, p42/44 MAPK, JAK2 and PLCγ1 in select cell lines. CTCE-9908 was able to specifically inhibit downstream signaling of Akt, p42/44 MAPK and JAK2. Decrease in cell proliferation (20–30%, p < .05), increase in cell apoptosis (20–40 %, p < .05) and cell cycle arrest was also observed with CXCR4 blockade. CTCE-9908 significantly inhibited migration and invasion (68–93 %, p < .05) in our cell lines. Conclusions: CXCR4-CXCL12 axis may be important in EWS and RMS metastasis. These results provide evidence that CTCE-9908 may be a novel therapy for these sarcomas.

No significant financial relationships to disclose.

Use of genetic variants to predict clinical outcome in patients (pts) with metastatic colorectal cancer (mCRC) treated with first-line 5-FU or capecitabine in combination with oxaliplatin and bevacizumab (FOLFOX/BV or XELOX/BV)

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Background: Recent studies suggested polymorphisms involved in angiogenesis related genes associated with clinical outcome in pts treated with the VEGF-inhibitor bevacizumab. (Schneider et al. JCO 2008, Manegold et al ASCO 2008). We evaluated functional polymorphisms involved in angiogenesis- (VEGF, KDR, IL-6, CXCR1 and-2), apoptosis (p53) and cell-proliferation (MMP2,-7 and-9, ICAM)-related pathways in an expanded patient cohort for their potential prognostic or predictive role in clinical outcome. Methods: Genomic DNA was extracted from 79 mCRC pts (treated with first-line FOLFOX/BV or XELOX/BV at USC) from peripheral blood. Genotyping was performed using PCR-RFLP assays or direct sequencing. Results: 79 pts (47 men, 32 women) with a median age of 56 years (range 29–81), were treated with either FOLFOX/BV (33 pts) or XELOX/BV (46 pts). Radiologic response: 2/79 pts (3%) CR, 41/79 pts (52%) PR, 32/79 pts (41%) SD and 3/79 pts (4%) DP. At a median follow-up of 32.0 months (range: 1.4- 47.8 months), the median time to progression was 10.8 months (95% CI: 8.1–14.9). We found IL-6 G- 174C (p=0.025, Fisher's exact test) and p53 codon 72 (p=0.029, Fisher's exact test) polymorphisms associated with response to BV-therapy. Furthermore, there were statistically significant associations between genomic polymorphisms in MMP-9, CXCR-1 and PFS (p=0.023 and p=0.014, respectively, log-rank test). Pts with 2 G- alleles in CXCR-1 G+2607C (median PFS=13.7 months, 95% CI:8.4–16.4) and pts homozygous for the C-allele in MMP-9 C-1562T (median PFS= 13.9 months, 95% CI: 10.1–15.8) had longer PFS compared to pts with any C-allele in CXCR-1 G+2607C (median PFS = 7.9 months, 95% CI: 6.9–10.2) and pts with any T-allele in MMP-9 C-1562T (median PFS 7.2 months, 95% CI: 5.3–11.0), respectively. Conclusions: These are the first data to predict clinical outcome in mCRC pts treated with FOLFOX/BV or XELOX/BV. Our data demonstrate that functional polymorphisms in angiogenesis related genes predict response and PFS in pts treated with the angiogenesis- inhibitor BV. However, confirmation of these findings in larger, prospective genotype-guided clinical trials is warranted.

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PI3K/Akt mediates expression of TNF-alpha mRNA and activation of NF-kappaB in calyculin A-treated primary osteoblasts

OBJECTIVE

The effect of calyculin A (CA), a serine/threonine protein phosphatase inhibitor, on tumor necrosis factor-alpha (TNF-alpha) in primary osteoblasts was investigated to determine whether protein phosphatases could affect primary osteoblasts and if so which signaling pathways would be involved.

MATERIALS AND METHODS

Primary osteoblasts were prepared from newborn rat calvaria. Cells were treated with 1 nM CA for different time periods. The expressions of TNF-alpha and GAPDH mRNA were determined by RT-PCR. Cell extracts were subjected to SDS-PAGE and the activation of Akt and NF-kappaB were analyzed by western blotting.

RESULTS

Calyculin A-treatment markedly increased the expression of TNF-alpha mRNA and enhanced the phosphorylation level of Akt (Ser473) in these cells. Pretreatment with the PI3K inhibitor LY294002 suppressed the increase in TNF-alpha mRNA expression and the phosphorylation of Akt in response to CA. Western blot analysis showed that CA stimulated the phosphorylation and nuclear translocation of NF-kappaB in primary osteoblasts, and these responses were blocked by pretreatment with LY294002.

CONCLUSION

Calyculin A elicits activation of PI3K/Akt pathway which leads to expression of TNF-alpha mRNA and activation of NF-kappaB. This NF-kappaB activation involves both phosphorylation and nuclear translocation of NF-kappaB.

Alarmins and antimicrobial immunity

Alarmins are endogenous mediators capable of enhancing innate and adaptive immune response through induction of concomitant recruitment and activation of antigen-presenting cells. Here we provide a brief overview of various alarmins, highlight their critical roles in innate and adaptive antimicrobial immunity, and speculate on potential usage of alarmins in combating aspergillosis.

Ovarian volume and follicle number in the diagnosis of polycystic ovary syndrome in Chinese women

OBJECTIVE

To assess the value of ovarian volume and follicle number in the diagnosis of polycystic ovary syndrome (PCOS) in a Chinese population.

METHODS

This study included 432 women with PCOS selected using the National Institutes of Health criteria, who were compared with 153 age-matched women as controls. All participants were given a transvaginal or transrectal ultrasound scan during day 3-5 of the menstrual cycle (for regularly menstruating women) or randomly (for oligomenorrheic or amenorrheic women). The ovarian volume (calculated using the simplified formula: 0.5 x length x height x width) and follicle number were obtained and the best diagnostic cut-off values were evaluated using receiver-operating characteristics (ROC)-curve analysis.

RESULTS

The 10(th) and 90(th) centiles of ovarian volume in PCOS patients were 4.89 and 15.79 cm(3), respectively, and the median was 9.21 cm(3); the 10(th) and 90(th) centiles of follicle number were 8 and 19, respectively, and the median was 12. The 10(th) and 90(th) centiles of ovarian volume in controls were 2.43 and 7.75 cm(3), respectively, and the median was 4.46 cm(3); the 10(th) and 90(th) centiles of follicle number were 3 and 10, respectively, and the median was 6. The differences in ovarian volume and follicle number between patients and controls were statistically significant. The areas under the ROC curves for mean ovarian volume (MOV), maximum ovarian volume (MaxOV), mean follicle number (MFN) and maximum follicle number (MaxFN) to diagnose PCOS were 0.898, 0.882, 0.909 and 0.911, respectively. Setting the threshold for MOV at 6.4 cm(3) (sensitivity 81%, specificity 85.6%), the threshold for MaxOV at 7.9 cm(3) (sensitivity 78%, specificity 85.6%), the threshold for MFN at 10 (sensitivity 85.2%, specificity 88.8%) and the threshold for MaxFN at 12 (sensitivity 85.2%, specificity 92.6%) obtained the best compromise between sensitivity and specificity, based on the Youden index.

CONCLUSIONS

We conclude that ovarian volume and follicle number have satisfactory power for use in the diagnosis of PCOS. Cut-offs of 6.4 cm(3), 7.9 cm(3), 10 and 12, for MOV, MaxOV, MFN and MaxFN, respectively, obtained the best compromise between sensitivity and specificity for the diagnosis of PCOS in Chinese women.

Wealth of opportunity - the C1 domain as a target for drug development

The diacylglycerol-responsive C1 domains of protein kinase C and of the related classes of signaling proteins represent highly attractive targets for drug development. The signaling functions that are regulated by C1 domains are central to cellular control, thereby impacting many pathological conditions. Our understanding of the diacylglycerol signaling pathways provides great confidence in the utility of intervention in these pathways for treatment of cancer and other conditions. Multiple compounds directed at these signaling proteins, including compounds directed at the C1 domains, are currently in clinical trials, providing strong validation for these targets. Extensive understanding of the structure and function of C1 domains, coupled with detailed insights into the molecular details of ligand - C1 domain interactions, provides a solid basis for rational and semi-rational drug design. Finally, the complexity of the factors contributing to ligand - C1 domain interactions affords abundant opportunities for manipulation of selectivity; indeed, substantially selective compounds have already been identified.

Polymorphisms in VEGF and IL-8 predict tumor recurrence in stage III colon cancer

BACKGROUND

Identifying molecular markers for tumor recurrence is critical in successfully selecting patients with stage III colon cancer who are more likely to benefit from adjuvant chemotherapy. The present study analyzed a subset of 10 polymorphisms within eight genes involved in the tumor angiogenesis pathway and their impact on prognosis in stage III colon cancer patients treated with adjuvant chemotherapy.

PATIENTS AND METHODS

Blood samples were obtained from 125 patients with locally advanced colon cancer at University of Southern California medical facilities. DNA was extracted from peripheral blood and the genotypes were analyzed using PCR-restriction fragment length polymorphism and 5'-end [gamma-(33)P] ATP-labeled PCR protocols.

RESULTS

Polymorphisms in vascular endothelial growth factor (VEGF) (C+936T; P = 0.003, log-rank test) and interleukin-8 (IL-8) (T-251A; P = 0.04, log-rank test) were independently associated with risk of recurrence in stage III colon cancer patients. In combined analysis, grouping alleles into favorable versus nonfavorable alleles, high expression variants of VEGF C+936T and IL-8 T-251A were associated with a higher likelihood of developing tumor recurrence (P < 0.001).

CONCLUSION

High expression variants of VEGF C+936T and IL-8 T-251A were associated with shorter time to tumor recurrence, indicating that the analysis of angiogenesis-related gene polymorphisms may help to identify patient subgroups at high risk for tumor recurrence.