The histone deacetylase inhibitors vorinostat and romidepsin downmodulate IL-10 expression in cutaneous T-cell lymphoma cells

BACKGROUND AND PURPOSE

Vorinostat and romidepsin are histone deacetylase inhibitors (HDI), approved for the treatment of cutaneous T-cell lymphoma (CTCL). However, the mechanism(s) by which these drugs exert their anti-cancer effects are not fully understood. Since CTCL is associated with immune dysregulation, we investigated whether these HDI modulated cytokine expression in CTCL cells.

EXPERIMENTAL APPROACH

CTCL cell lines and primary CTCL cells were treated in vitro with vorinostat or romidepsin, or with STAT3 pathway inhibitors. Cell cycle parameters and apoptosis were analysed by propidium iodide and annexin V/propidium iodide staining respectively. Cytokine expression was analysed using QRT-PCR and elisa assays. STAT3 expression/phosphorylation and transcriptional activity were analysed using immunoblotting and transfection/reporter assays respectively.

KEY RESULTS

Vorinostat and romidepsin strongly down-regulated expression of the immunosuppressive cytokine, interleukin (IL)-10, frequently overexpressed in CTCL, at both the RNA and protein level in CTCL cell lines and at the RNA level in primary CTCL cells. Vorinostat and romidepsin also increased expression of IFNG RNA and decreased expression of IL-2 and IL-4 RNA, although to a lesser extent compared to IL-10. Transient exposure to vorinostat was sufficient to suppress IL-10 secretion but was not sufficient to irreversibly commit cells to undergo cell death. STAT3 pathway inhibitors decreased production of IL-10 and vorinostat/romidepsin partially decreased STAT3-dependent transcription without effects on STAT3 expression or phosphorylation.

CONCLUSIONS AND IMPLICATIONS

These results demonstrate that HDI modulate cytokine expression in CTCL cells, potentially via effects on STAT3. Immunomodulation may contribute to the clinical activity of HDI in this disease.

Caveolin-1 as a biomarker of Src family kinase/Abl inhibition in castrate-resistant prostate cancer

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Background: Bone metastases cause significant morbidity in men with castrate-resistant prostate cancer (CRPC). Caveolin-1 (Cav-1), a Src kinase substrate, is overexpressed in primary prostate cancer (PCa) and in PCa bone metastases. In addition, PCa-derived and secreted Cav-1 contributes to malignant progression. We reasoned that Cav-1 may serve as a biomarker of dasatinib (a Src family kinase [SFK]/Abl inhibitor) activity in CRPC patients enrolled in a phase II clinical trial of docetaxel plus dasatinib.

Methods: Levels of prostate-specific antigen (PSA), Cav-1, and markers of bone turnover were measured from baseline and cycle-2, day-1 samples from patients (n = 32) enrolled in this trial. Changes in these markers were stratified by response (responders [R] vs. nonresponders [NR]) and by predominant disease site (lymph node vs. bone). We evaluated Cav-1 expression in human PCa bone metastases samples from trial patients by immunohistochemistry. In parallel, Cav-1 secretion in response to dasatinib treatment was analyzed in PCa cells and osteoblasts.

Results: Serum Cav-1 levels correlated directly with PSA levels in responding patients with node-positive disease (R vs. NR, p = 0.08) but correlated inversely in responding patients with bone-predominant disease (R vs. NR, p = 0.001). Serum from a separate cohort of patients treated with docetaxel only showed no effect on serum Cav-1 levels (R vs. NR, p = 0.85). Levels of Cav-1 were high in the active OBLs in bone specimens with PCa metastases, but not in bone specimens without metastases. Dasatinib treatment led to reduced secretion of Cav-1 in PC-3 and DU145 PCa cells but to increased secretion of Cav-1 in primary mouse osteoblasts or pre-osteoblast MC3T3-E1 cells.

Conclusions: Our results suggest that serum Cav-1 serves as a novel discriminating biomarker for SFK/Abl inhibition in both node-positive and bone-metastatic CRPC. The expression of Cav-1 in OBLs of patients with PCa bone metastases suggests that tumor-associated OBLs are an important source of Cav-1 production in bone marrow. Our data provide evidence that the increase in serum Cav-1 in these patients with bone disease likely occurs through a direct effect of dasatinib on osteoblasts.

No significant financial relationships to disclose.

Strain, Structure and Electronic States in MBE Grown (Nb, Ti)O2 Mixed Rutile

We have grown and characterized epitaxial NbxTi1-xO2 on TiO2(110) and (100) for the purpose of investigating the role of chemically-inequivalent metal atoms on the thermal and photocatalytic properties of TiO2. Our goal is to introduce, in a highly controlled fashion, a Group VA transition metal into the lattice of a Group IVA transition metal oxide without altering the crystallographic structure. So doing would alter the electronic structure in interesting and potentially useful ways by the addition of one valence electron per substituted metal atom. However, strain builds in the film as more Nb is added at a rate which depends on the crystallographic orientation of the growth direction. Films grown along (110) can accommodate Nb mole fractions as high as ˜0.3 without forming misfit dislocations, whereas those grown along (100) are limited to ˜10 at. % Nb. Nb-O bond lengths in NbxTil−xO2 are the same as Ti-O bond lengths in pure TiO2 prior to the onset of dislocation formation. The extra 4d valence electron per Nb atom forms a nonbonding band which is degenerate with bonding states in the valence band region.

Neoadjuvant therapy for adenocarcinomas of the duodenum and ampulla of Vater

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Background: Adenocarcinomas of the ampulla of Vater and duodenum are both rare periampullary tumors with limited data regarding the use of neoadjuvant therapy. We sought to better define the role of neoadjuvant therapy as compared to adjuvant therapy in patients with high-risk disease.

Methods: Retrospective review of the M. D. Anderson Cancer Center (MDACC) tumor registry from 5/1990 to 1/2009 identified 66 cases of ampullary (26 neoadjuvant, 40 adjuvant) and 41 cases of duodenal adenocarcinoma (18 neoadjuvant, 23 adjuvant). Only patients who received adjuvant or neoadjuvant therapy and underwent surgical resection at MDACC where included. High-risk factors were defined as T3 or T4, poor differentiation, or lymph node involvement. Relapse-free survival (RFS) and overall survival (OS) were calculated from the start of surgical resection.

Results: Median age was 61 yrs (range 30-82) and 39% were female. Neoadjuvant (n=44) and adjuvant therapy (n=63) consisted of 5-FU chemoradiation in 93% and 65%, systemic 5-FU based chemotherapy only in 5% and 24%, and gemcitabine or irinotecan based therapy in 2% and 11%, respectively. Pathological high-risk factors were seen in 77% and 95% of neoadjuvant and adjuvant patients, respectively. Indications for neoadjuvant therapy were high risk disease (70%), poor surgical candidate (16%), and concern for possible metastatic disease (14%). In the neoadjuvant group T and N downstaging were observed in 25% and 32% of patients, respectively; 3 patients (7%) had a pathological complete response. Neoadjuvant as compared to adjuvant therapy had similar 5-year OS (66% vs. 59%, p =0.8) and 5-year RFS (54% vs. 59%, p=0.4). Variables significant (p <0.05) in the multivariate analysis for OS were age >60 yrs, lymph node involvement, and margin positivity; and for RFS were lymph node involvement and margin positivity. Neither tumor type (duodenal vs. ampullary; OS HR: 1.6, p =0.2; RFS HR: 0.9, p=0.8) nor treatment type (neoadjuvant vs. adjuvant; OS HR: 1.2, p =0.6; RFS HR: 1.1, p=0.7) were significant for OS or RFS in the multivariate model.

Conclusions: Neoadjuvant therapy appears to be a viable approach for high-risk duodenal and ampullary adenocarcinomas. Further investigation of this treatment approach is needed.

[Table: see text]

Survival advantage associated with palliative oophorectomy in patients with metastatic colorectal cancer (CRC) to the ovaries (mCRC-O): A single institution retrospective analysis

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Background: The ovaries are an uncommon site for secondary spread from metastatic CRC. We hypothesize that palliative oophorectomy improves survival among patients with mCRC-O.

Methods: We undertook a single institution IRB-approved (DR-09-623) retrospective evaluation of women with mCRC-O from 2001-2008; 110 pts with ovarian metastases and follow-up information for survival analysis were identified out of 3,776 female pts with CRC (2.9%). Survival data was calculated from the date of diagnosis of ovarian metastases (by pathology or radiology) to date of death.

Results: Median age of patients was 49 years (range 19-82); median duration of follow-up was 49 months. Twenty patients were identified from 1,758 female patients with CRC seen at our institution from 2001-2004 (1.1%) and ninety patients identified from 2,018 female CRC patients from 2005-2008 (4.5%). KRAS mutation was present in the primary tumor in 23 of 43 (54%). Sixteen evaluable patients who received systemic chemotherapy with mCRC-O and other sites of metastatic disease were identified; five (31%) had a mixed radiographic response (progression in the ovarian metastases with disease response in other sites of metastases). Seventy-one (64.5%) patients had metastatic disease at the time of initial presentation; 39 (35.5%) had completely resected stage II or III CRC with mCRC-O occurring at a later date. 86 (78.2%) underwent unilateral or bilateral oophorectomy for treatment of their disease. Patients who had metastatic disease at presentation and underwent oophorectomy had a median survival of 39.4 months versus 18.2 months for those with ovarian metastases left in situ (p < 0.0001); patients who developed ovarian relapse after prior colectomy and subsequently underwent oophorectomy had a median survival of 50 months versus 12 months for those patients who did not (p = 0.001). Patients with mCRC-O and peritoneal metastases had a significantly worse survival (p = 0.003).

Conclusions: This single institution retrospective data analysis suggests that women with colorectal cancer metastatic to the ovaries may derive a survival benefit from palliative oophorectomy.

No significant financial relationships to disclose.

Retrospective evaluation of patients with colorectal cancer (CRC) and type II non-insulin-dependent diabetes (NIDDM)

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Background: Patients with NIDDM have an increased risk of colorectal adenomas and CRC possibly mediated through the insulin growth factor receptor pathway. Metformin is associated with anticancer efficacy in preclinical models and a lower risk of cancer mortality in patients with NIDDM. We undertook to evaluate the difference in outcome in NIDDM patients with CRC based upon their medications taken for glycemic control.

Methods: We conducted an IRB-approved (DR09-0719) retrospective analysis of 4,758 patients seen at a single institution (University of Texas M. D. Anderson) with CRC between the years of 2005-2008, to determine the prevalence of NIDDM in this patient population, in addition to determining whether patient survival differs based upon their diabetic therapy.

Results: 425 out of 4,758 CRC patients (8.9%) were identified as having NIDDM. Gender, male:female 283:142 (67%, 33%), age, mean 62 years (range 31-91), stage I/II/III/IV 37:55:175:158 (8.7%, 12.9%, 41.2%, 37.2%). Overall survival (OS) for the 397 patients with follow-up data available, by univariable Kaplan Meier analysis, was 63.7 months (95% confidence interval (CI), 52.3-75.5). Patients with NIDDM and CRC treated with metformin as one of their diabetic medications had a survival of 76.9 months (95% CI, 61.4-102.4) as compared to 56.9 months in those patients not treated with metformin (95% CI, 44.8- 68.8), p = 0.048. By using a Cox regression model adjusted for age, sex, race, body mass index, and initial stage of disease we demonstrated that NIDDM patients treated with metformin had a 30% improvement in OS when compared to NIDDM patients treated with other diabetic agents. There was a non-statistically significant trend toward higher complete and minor pathologic response rate (≤ 10% residual tumor) in NIDDM patients with rectal cancer receiving chemoradiation who were treated with metformin when compared to those who were not (14/19, 74% vs. 9/19, 47%, p = 0.09).

Conclusions: In this analysis the use of metformin in NIDDM patients with CRC was associated with an improved overall survival. While these results are consistent with the findings in other solid tumors they will need to be validated in other colorectal cancer data sets.

No significant financial relationships to disclose.

Treatment of VHL patients with sunitinib: Clinical observations and translational studies

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Background: Von Hippel Lindau (VHL) disease induces vascular lesions in multiple organs. Surgical intervention is the treatment of choice. Effective, safe systemic therapy will greatly improve the quality of life of these individuals. Methods: Patients with genetically confirmed VHL were enrolled on an IRB approved trial. Eligibility criteria included retinal angiomas, hemangioblastomas (HBs) measuring at least 5mm, renal cell carcinoma (RCC) 1 to 3 cm and pancreatic neuroendocrine tumors (NETs) 1 to 3 cm. Patients received sunitinib 50mg/day for 28 days/14 days off for four cycles. Scans were performed at baseline, and after cycles two and four. A separate set of 20 formalin-fixed paraffin embedded HBs and 20 RCCs were used for laser scanning cytometry (LSC) analysis of total and phospho vascular endothelial growth factor receptor (pVEGFR) and phospho platelet derived growth factor receptor (pPDGFR) levels in tumor endothelium. Results: Twelve patients were evaluable for response and toxicity. Eight had RCCs, nine had CNS lesions, and three had pancreatic NETs. Tumor size reduction was seen in 16/19 evaluable RCC lesions (95%CI 0.60, 0.97), 3/5 NETs (95%CI 0.15, 0.95) and 6/19 HBs (95%CI 0.13, 0.57). Two patients came off study for treatment related side effects, one patient progressed on study, and two patients did not complete the scheduled course of therapy. LSC analysis demonstrated significantly lower phospho VEGFR levels in HBs when compared with RCC. The mean (SD) of pVEGFR levels in log-transformation were 11.27 (0.49) and 11.75 (0.37) for HBs and RCC respectively (p = 0.003). The mean (SD) of pVEGFR to VEGFR ratio was .21 (0.12) versus 0.37 (0.43), for HBs and RCC respsectively (p = 0.043). Conclusions: Sunitinib treatment of patients with VHL resulted in consistent decrease of RCC and NET tumor size. The discrepant response to sunitinib in RCC and HBs may be explained by differential dependence on VEGFR activation in tumor endothelium.

[Table: see text]