Gastrointestinal toxicity of vorinostat: reanalysis of phase 1 study results with emphasis on dose-volume effects of pelvic radiotherapy

<p>Abstract</p> <p>Background</p> <p>In early-phase studies with targeted therapeutics and radiotherapy, it may be difficult to decide whether an adverse event should be considered a dose-limiting toxicity (DLT) of the investigational systemic agent, as acute normal tissue toxicity is frequently encountered with radiation alone. We have reanalyzed the toxicity data from a recently conducted phase 1 study on vorinostat, a histone deacetylase inhibitor, in combination with pelvic palliative radiotherapy, with emphasis on the dose distribution within the irradiated bowel volume to the development of DLT.</p> <p>Findings</p> <p>Of 14 eligible patients, three individuals experienced Common Terminology Criteria of Adverse Events grade 3 gastrointestinal and related toxicities, representing a toxicity profile vorinostat has in common with radiotherapy to pelvic target volumes. For each study patient, the relative volumes of small bowel receiving radiation doses between 6 Gy and 30 Gy at 6-Gy intervals (V6-V30) were determined from the treatment-planning computed tomography scans. The single patient that experienced a DLT at the second highest dose level of vorinostat, which was determined as the maximum-tolerated dose, had V6-V30 dose-volume estimates that were considerably higher than any other study patient. This patient may have experienced an adverse radiation dose-volume effect rather than a toxic effect of the investigational drug.</p> <p>Conclusions</p> <p>When reporting early-phase trial results on the tolerability of a systemic targeted therapeutic used as potential radiosensitizing agent, radiation dose-volume effects should be quantified to enable full interpretation of the study toxicity profile.</p> <p>Trial registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00455351">NCT00455351</a></p

Radiosensitization by the histone deacetylase inhibitor vorinostat under hypoxia and with capecitabine in experimental colorectal carcinoma

Background The histone deacetylase inhibitor vorinostat is a candidate radiosensitizer in locally advanced rectal cancer (LARC). Radiosensitivity is critically influenced by hypoxia; hence, it is important to evaluate the efficacy of potential radiosensitizers under variable tissue oxygenation. Since fluoropyrimidine-based chemoradiotherapy (CRT) is the only clinically validated regimen in LARC, efficacy in combination with this established regimen should be assessed in preclinical models before a candidate drug enters clinical trials. Methods Radiosensitization by vorinostat under hypoxia was studied in four colorectal carcinoma cell lines and in one colorectal carcinoma xenograft model by analysis of clonogenic survival and tumor growth delay, respectively. Radiosensitizing effects of vorinostat in combination with capecitabine were assessed by evaluation of tumor growth delay in two colorectal carcinoma xenografts models. Results Under hypoxia, radiosensitization by vorinostat was demonstrated in vitro in terms of decreased clonogenicity and in vivo as inhibition of tumor growth. Adding vorinostat to capecitabine-based CRT increased radiosensitivity of xenografts in terms of inhibited tumor growth. Conclusions Vorinostat sensitized colorectal carcinoma cells to radiation under hypoxia in vitro and in vivo and improved therapeutic efficacy in combination with capecitabine-based CRT in vivo. The results encourage implementation of vorinostat into CRT in LARC trials

Principal component analysis for the comparison of metabolic profiles from human rectal cancer biopsies and colorectal xenografts using high-resolution magic angle spinning 1H magnetic resonance spectroscopy

<p>Abstract</p> <p>Background</p> <p>This study was conducted in order to elucidate metabolic differences between human rectal cancer biopsies and colorectal HT29, HCT116 and SW620 xenografts by using high-resolution magnetic angle spinning (MAS) magnetic resonance spectroscopy (MRS) and for determination of the most appropriate human rectal xenograft model for preclinical MR spectroscopy studies. A further aim was to investigate metabolic changes following irradiation of HT29 xenografts.</p> <p>Methods</p> <p>HR MAS MRS of tissue samples from xenografts and rectal biopsies were obtained with a Bruker Avance DRX600 spectrometer and analyzed using principal component analysis (PCA) and partial least square (PLS) regression analysis.</p> <p>Results and conclusion</p> <p>HR MAS MRS enabled assignment of 27 metabolites. Score plots from PCA of spin-echo and single-pulse spectra revealed separate clusters of the different xenografts and rectal biopsies, reflecting underlying differences in metabolite composition. The loading profile indicated that clustering was mainly based on differences in relative amounts of lipids, lactate and choline-containing compounds, with HT29 exhibiting the metabolic profile most similar to human rectal cancers tissue. Due to high necrotic fractions in the HT29 xenografts, radiation-induced changes were not detected when comparing spectra from untreated and irradiated HT29 xenografts. However, PLS calibration relating spectral data to the necrotic fraction revealed a significant correlation, indicating that necrotic fraction can be assessed from the MR spectra.</p

The clinical value of C-reactive protein and its association with tumour location in patients undergoing curative surgery for colorectal cancer – a ScotScan collaborative study

Introduction: The presence of preoperative systemic inflammatory response (SIR) is an established negative prognostic factor for patients diagnosed with colorectal cancer (CRC). C-reactive protein (CRP) is known to be implicated in detrimental immune responses. The biological differences between right-sided and left-sided CRC are gaining increasing attention. Our aim was to analyse the prognostic value of CRP and explore the association between tumour location and SIR. Material and methods: A total of 2059 patients treated for stage I–III CRC, identified from the prospectively sampled ScotScan Collaborative dataset, were included. The clinical and prognostic value of five CRP levels (&lt;10/11–30/31–60/61–100/&gt;100 mg/l) were examined. Additionally, the relationship between SIR and tumour location was explored. Results: Increasing levels of CRP were associated with impaired overall and cancer-specific outcome. Presence of SIR was independently associated with right-sided tumour location (p&lt;0.001). However, the impact of SIR on cancer-specific survival (CSS) was greater for left-sided tumour location, even when adjusted for other clinicopathological factors. Conclusions: This study confirms CRP as a routinely available, valid, and clinically relevant strong prognostic marker of SIR in CRC patients. Right-sided tumours were more often associated with SIR, but the prognostic impact was stronger in left-sided tumours

Early prediction of response to radiotherapy and androgen-deprivation therapy in prostate cancer by repeated functional MRI: a preclinical study

<p>Abstract</p> <p>Background</p> <p>In modern cancer medicine, morphological magnetic resonance imaging (MRI) is routinely used in diagnostics, treatment planning and assessment of therapeutic efficacy. During the past decade, functional imaging techniques like diffusion-weighted (DW) MRI and dynamic contrast-enhanced (DCE) MRI have increasingly been included into imaging protocols, allowing extraction of intratumoral information of underlying vascular, molecular and physiological mechanisms, not available in morphological images. Separately, pre-treatment and early changes in functional parameters obtained from DWMRI and DCEMRI have shown potential in predicting therapy response. We hypothesized that the combination of several functional parameters increased the predictive power.</p> <p>Methods</p> <p>We challenged this hypothesis by using an artificial neural network (ANN) approach, exploiting nonlinear relationships between individual variables, which is particularly suitable in treatment response prediction involving complex cancer data. A clinical scenario was elicited by using 32 mice with human prostate carcinoma xenografts receiving combinations of androgen-deprivation therapy and/or radiotherapy. Pre-radiation and on days 1 and 9 following radiation three repeated DWMRI and DCEMRI acquisitions enabled derivation of the apparent diffusion coefficient (ADC) and the vascular biomarker <it>K</it>^trans, which together with tumor volumes and the established biomarker prostate-specific antigen (PSA), were used as inputs to a back propagation neural network, independently and combined, in order to explore their feasibility of predicting individual treatment response measured as 30 days post-RT tumor volumes.</p> <p>Results</p> <p>ADC, volumes and PSA as inputs to the model revealed a correlation coefficient of 0.54 (p < 0.001) between predicted and measured treatment response, while <it>K</it>^trans, volumes and PSA gave a correlation coefficient of 0.66 (p < 0.001). The combination of all parameters (ADC, <it>K</it>^trans, volumes, PSA) successfully predicted treatment response with a correlation coefficient of 0.85 (p < 0.001).</p> <p>Conclusions</p> <p>We have in a preclinical investigation showed that the combination of early changes in several functional MRI parameters provides additional information about therapy response. If such an approach could be clinically validated, it may become a tool to help identifying non-responding patients early in treatment, allowing these patients to be considered for alternative treatment strategies, and, thus, providing a contribution to the development of individualized cancer therapy.</p

Genome wide single cell analysis of chemotherapy resistant metastatic cells in a case of gastroesophageal adenocarcinoma

<p>Abstract</p> <p>Background</p> <p>Metastatic progression due to development or enrichment of therapy-resistant tumor cells is eventually lethal. Molecular characterization of such chemotherapy resistant tumor cell clones may identify markers responsible for malignant progression and potential targets for new treatment. Here, in a case of stage IV adenocarcinoma of the gastroesophageal junction, we report the successful genome wide analysis using array comparative genomic hybridization (CGH) of DNA from only fourteen tumor cells using a bead-based single cell selection method from a bone metastasis progressing during chemotherapy.</p> <p>Case presentation</p> <p>In a case of metastatic adenocarcinoma of the gastroesophageal junction, the progression of bone metastasis was observed during a chemotherapy regimen of epirubicin, oxaliplatin and capecitabine, whereas lung-, liver and lymph node metastases as well as the primary tumor were regressing. A bone marrow aspirate sampled at the site of progressing metastasis in the right iliac bone was performed, and single cell molecular analysis using array-CGH of Epithelial Specific Antigen (ESA)-positive metastatic cells, and revealed two distinct regions of amplification, 12p12.1 and 17q12-q21.2 amplicons, containing the KRAS (12p) and ERBB2 (HER2/NEU) (17q) oncogenes. Further intrapatient tumor heterogeneity of these highlighted gene copy number changes was analyzed by fluorescence in situ hybridization (FISH) in all available primary and metastatic tumor biopsies, and ErbB2 protein expression was investigated by immunohistochemistry.</p> <p>ERBB2 was heterogeneously amplified by FISH analysis in the primary tumor, as well as liver and bone metastasis, but homogenously amplified in biopsy specimens from a progressing bone metastasis after three initial cycles of chemotherapy, indicating a possible enrichment of erbB2 positive tumor cells in the progressing bone marrow metastasis during chemotherapy. A similar amplification profile was detected for wild-type KRAS, although more heterogeneously expressed in the bone metastasis progressing on chemotherapy. Correspondingly, the erbB2 protein was found heterogeneously expressed by immunohistochemical staining of the primary tumor of the gastroesophageal junction, while negative in liver and bone metastases, but after three initial cycles of palliative chemotherapy with epirubicin, oxaliplatin and capecetabine, the representative bone metastasis stained strongly positive for erbB2.</p> <p>Conclusion</p> <p>Global analysis of genetic aberrations, as illustrated by performing array-CGH analysis on genomic DNA from only a few selected tumor cells of interest sampled from a progressing bone metastasis, can identify relevant therapeutic targets and genetic aberrations involved in malignant progression, thus emphasizing the importance and feasibility of this powerful tool on the road to more personalized cancer therapies in the future.</p

High Expression of Wee1 Is Associated with Poor Disease-Free Survival in Malignant Melanoma: Potential for Targeted Therapy

Notoriously resistant malignant melanoma is one of the most increasing forms of cancer worldwide; there is thus a precarious need for new treatment options. The Wee1 kinase is a major regulator of the G2/M checkpoint, and halts the cell cycle by adding a negative phosphorylation on CDK1 (Tyr15). Additionally, Wee1 has a function in safeguarding the genome integrity during DNA synthesis. To assess the role of Wee1 in development and progression of malignant melanoma we examined its expression in a panel of paraffin-embedded patient derived tissue of benign nevi and primary- and metastatic melanomas, as well as in agarose-embedded cultured melanocytes. We found that Wee1 expression increased in the direction of malignancy, and showed a strong, positive correlation with known biomarkers involved in cell cycle regulation: Cyclin A (p<0.0001), Ki67 (p<0.0001), Cyclin D3 (p = 0.001), p21Cip1/WAF1 (p = 0.003), p53 (p = 0.025). Furthermore, high Wee1 expression was associated with thicker primary tumors (p = 0.001), ulceration (p = 0.005) and poor disease-free survival (p = 0.008). Transfections using siWee1 in metastatic melanoma cell lines; WM239WTp53, WM45.1MUTp53 and LOXWTp53, further support our hypothesis of a tumor promoting role of Wee1 in melanomas. Whereas no effect was observed in LOX cells, transfection with siWee1 led to accumulation of cells in G1/S and S phase of the cell cycle in WM239 and WM45.1 cells, respectively. Both latter cell lines displayed DNA damage and induction of apoptosis, in the absence of Wee1, indicating that the effect of silencing Wee1 may not be solely dependent of the p53 status of the cells. Together these results reveal the importance of Wee1 as a prognostic biomarker in melanomas, and indicate a potential role for targeted therapy, alone or in combination with other agents

Enrichment methods to detect bone marrow micrometastases in breast carcinoma patients: clinical relevance

INTRODUCTION: Improving technologies for the detection and purification of bone marrow (BM) micrometastatic cells in breast cancer patients should lead to earlier prognosis of the risk of relapse and should make it possible to design more appropriate therapies. The technique used has to overcome the challenges resulting from the small number of target cells (one per million hematopoietic cells) and the heterogeneous expression of micrometastatic cell markers. In the present study, we have assessed the clinical relevance of current methods aimed at detecting rare disseminated carcinoma cells. METHODS: BM aspirates from 32 carcinoma patients were screened for the presence of micrometastatic cells positive for epithelial cell adhesion molecule and positive for cytokeratins, using optimized immunodetection methods. A comparison with data obtained for 46 control BM aspirates and a correlation with the clinical status of patients were performed. RESULTS: We developed a sensitive and efficient immunomagnetic protocol for the enrichment of BM micrometastases. This method was used to divide 32 breast carcinoma patients into three categories according to their epithelial cell adhesion molecule status. These categories were highly correlated with the recently revised American Joint Committee on Cancer staging system for breast cancer, demonstrating the clinical relevance of this simple and reliable immunomagnetic technique. We also evaluated immunocytochemical detection of cytokeratin-positive cells and cytomorphological parameters. Immunocytochemistry-based methods for the detection of BM micrometastases did not provide any information about the clinical status of patients, but helped to refine the immunomagnetic data by confirming the presence of micrometastases in some cases. We also tested a new density gradient centrifugation system, able to enrich the tumor fraction of BM specimens by twofold to threefold as compared with standard Ficoll methods. CONCLUSION: These improved methods for the detection of micrometastatic cells in patient BM should help clinicians to predict the clinical status of breast cancer patients at the time of surgery or treatment

The fatty acid binding protein 7 (FABP7) is involved in proliferation and invasion of melanoma cells

<p>Abstract</p> <p>Background</p> <p>The molecular mechanisms underlying melanoma tumor development and progression are still not completely understood. One of the new candidates that emerged from a recent gene expression profiling study is <it>fatty acid-binding protein 7 </it>(<it>FABP7)</it>, involved in lipid metabolism, gene regulation, cell growth and differentiation.</p> <p>Methods</p> <p>We studied the functional role of FABP7 in human melanoma cell lines and using immunohistochemistry analyzed its expression pattern and clinical role in 11 nevi, 149 primary melanomas and 68 metastases.</p> <p>Results</p> <p>FABP7 mRNA and protein level is down-regulated following treatment of melanoma cell lines with a PKC activator (PMA) or MEK1 inhibitor (PD98059). Down-regulation of FABP7 using siRNA decreased cell proliferation and invasion but did not affect apoptosis. In clinical specimens, FABP7 was expressed in 91% of nevi, 71% of primary melanomas and 70% of metastases, with a cytoplasmic and/or nuclear localization. FABP7 expression was associated with tumor thickness in superficial spreading melanoma (P = 0.021). In addition, we observed a trend for an association between FABP7 expression and Ki-67 score (P = 0.070) and shorter relapse-free survival (P = 0.069) in this group of patients.</p> <p>Conclusion</p> <p>Our data suggest that FABP7 can be regulated by PKC and the MAPK/ERK1/2 pathway through independent mechanisms in melanoma cell lines. Furthermore, FABP7 is involved in cell proliferation and invasion <it>in vitro</it>, and may be associated with tumor progression in melanoma.</p