Molecular preservation by extraction and fixation, mPREF: a method for small molecule biomarker analysis and histology on exactly the same tissue

<p>Abstract</p> <p>Background</p> <p>Histopathology is the standard method for cancer diagnosis and grading to assess aggressiveness in clinical biopsies. Molecular biomarkers have also been described that are associated with cancer aggressiveness, however, the portion of tissue analyzed is often processed in a manner that is destructive to the tissue. We present here a new method for performing analysis of small molecule biomarkers and histology in exactly the same biopsy tissue.</p> <p>Methods</p> <p>Prostate needle biopsies were taken from surgical prostatectomy specimens and first fixed, each in a separate vial, in 2.5 ml of 80% methanol:water. The biopsies were fixed for 24 hrs at room temperature and then removed and post-processed using a non-formalin-based fixative (UMFIX), embedded, and analyzed by hematoxylin and eosin (H&E) and by immunohistochemical (IHC) staining. The retained alcohol pre-fixative was analyzed for small molecule biomarkers by mass spectrometry.</p> <p>Results</p> <p>H&E analysis was successful following the pre-fixation in 80% methanol. The presence or absence of tumor could be readily determined for all 96 biopsies analyzed. A subset of biopsy sections was analyzed by IHC, and cancerous and non-cancerous regions could be readily visualized by PIN4 staining. To demonstrate the suitability for analysis of small molecule biomarkers, 28 of the alcohol extracts were analyzed using a mass spectrometry-based metabolomics platform. All extracts tested yielded successful metabolite profiles. 260 named biochemical compounds were detected in the alcohol extracts. A comparison of the relative levels of compounds in cancer containing <it>vs</it>. non-cancer containing biopsies showed differences for 83 of the compounds. A comparison of the results with prior published reports showed good agreement between the current method and prior reported biomarker discovery methods that involve tissue destructive methods.</p> <p>Conclusions</p> <p>The Molecular Preservation by Extraction and Fixation (mPREF) method allows for the analysis of small molecule biomarkers from exactly the same tissue that is processed for histopathology.</p

The distribution of the therapeutic monoclonal antibodies cetuximab and trastuzumab within solid tumors

<p><b>Abstract</b></p> <p>Background</p> <p>Poor distribution of some anticancer drugs in solid tumors may limit their anti-tumor activity.</p> <p>Methods</p> <p>Here we used immunohistochemistry to quantify the distribution of the therapeutic monoclonal antibodies cetuximab and trastuzumab in relation to blood vessels and to regions of hypoxia in human tumor xenografts. The antibodies were injected into mice implanted with human epidermoid carcinoma A431 or human breast carcinoma MDA-MB-231 transfected with <it>ERBB2 </it>(231-H2N) that express high levels of ErbB1 and ErbB2 respectively, or wild-type MDA-MB-231, which expresses intermediate levels of ErbB1 and low levels of ErbB2.</p> <p>Results</p> <p>The distribution of cetuximab in A431 xenografts and trastuzumab in 231-H2N xenografts was time and dose dependent. At early intervals after injection of 1 mg cetuximab into A431 xenografts, the concentration of cetuximab decreased with increasing distance from blood vessels, but became more uniformly distributed at later times; there remained however limited distribution and binding in hypoxic regions of tumors. Injection of lower doses of cetuximab led to heterogeneous distributions. Similar results were observed with trastuzumab in 231-H2N xenografts. In MDA-MB-231 xenografts, which express lower levels of ErbB1, homogeneity of distribution of cetuximab was achieved more rapidly.</p> <p>Conclusions</p> <p>Cetuximab and trastuzumab distribute slowly, but at higher doses achieve a relatively uniform distribution after about 24 hours, most likely due to their long half-lives in the circulation. There remains poor distribution within hypoxic regions of tumors.</p

Integrative mRNA profiling comparing cultured primary cells with clinical samples reveals PLK1 and C20orf20 as therapeutic targets in cutaneous squamous cell carcinoma

This work was funded by DebRA, the dystrophic epidermolysis bullosa research association (http:// www.debra.org.uk

Trastuzumab induces gastrointestinal side effects in HER2-overexpressing breast cancer patients

The original publication can be found at www.springerlink.comPurpose: To characterise the gastrointestinal toxicities associated with Trastuzumab administration in HER2-overexpressing breast cancer patients. Methods: All patients (n = 46) who received Trastuzumab as a single agent or in conjunction with conventional anti-cancer treatment within the Royal Adelaide Hospital Cancer Centre from 2002–2007 were included in this study. A retrospective analysis of case-notes was conducted to investigate the toxicities associated with Trastuzumab. Results: Trastuzumab as a single agent induced toxicities following 22% of administrations. Gastrointestinal toxicities were observed following 12% of administrations and included nausea and vomiting, diarrhoea, abdominal pain and bloating. However, other prominent toxicities that were not related to the gastrointestinal tract were also observed including fatigue and lung symptoms (10.4%). Elderly patients (≥60 years) and those with metastatic disease experienced the highest frequency of toxicity. Conclusion: Trastuzumab induces a range of gastrointestinal toxicities in HER2-overexpressing breast cancer patients. These toxicities are separate to those caused by concurrent chemotherapy and/or radiotherapy.Noor Al-Dasooqi, Joanne M. Bowen, Rachel J. Gibson, Thomas Sullivan, Jude Lees and Dorothy M. Keef

The influence of common polymorphisms on breast cancer

Breast cancer is one of the most frequently diagnosed cancers in the Western world and a significant cause of mortality worldwide. A small proportion of cases are accounted for by high-penetrance monogenic predisposition genes; however, this explains only a small fraction (less than 5%) of all breast cancers. Increasingly with advances in molecular technology and the development of large research consortia, the locations and identities of many low-penetrance genetic variants are being discovered. However, each variant has a very small effect similar to or smaller than many of the known environmental risk factors. It is therefore unlikely that these variants will be appropriate for predictive genetic testing, although they may identify novel pathways and genes which provide new insights and targets for therapeutic intervention. The future challenges will be identifying causal variants and determining how these low-penetrance alleles interact with each other and with environmental factors in order to usefully implement them in the practice of clinical medicine. Furthermore, it is clear that breast cancer comes in many forms with the tumour pathology and immunohistochemical profile already being used routinely as prognostic indicators and to inform treatment decisions. However, these indicators of prognosis are imperfect; two apparently identical tumours may have very different outcomes in different individuals. Inherited genetic variants may well be one of the other factors that need to be taken into account in assessing prognosis and planning treatment

Dacomitinib (PF-00299804), a second-generation irreversible pan-erbB receptor tyrosine kinase inhibitor, demonstrates remarkable activity against HER2-amplified uterine serous endometrial cancer in vitro

Uterine serous carcinoma (USC) is an aggressive subtype of endometrial cancer that carries an extremely poor prognosis. Up to 35% of USC may overexpress the epidermal growth factor receptor-2 (HER2/neu) at strong (i.e., 3+) level by immunohistochemistry (IHC) or harbor HER2/neu gene amplification by fluorescence in situ hybridization (FISH). In this study, we assessed the sensitivity of a panel of USC cell lines with and without HER2/neu gene amplification to dacomitinib (PF-00299804), an irreversible pan-human epidermal growth factor receptor tyrosine kinase inhibitor. Eight primary cell lines (i.e., four harboring HER2/neu gene amplification by FISH and four FISH-cell lines), all demonstrating similar in vitro growth rates, were evaluated in viability/proliferation assays. The effect of dacomitinib on cell growth, cell cycle distribution, and signaling was determined using flow cytometry-based assays. Dacomitinib caused a significantly stronger growth inhibition in HER2/neu FISH+ USC cell lines when compared to FISH- USC (dacomitinib half maximal inhibitory concentration (IC50) mean+/-SEM= 0.02803+/-0.003355 mu M in FISH+ versus 1.498+/-0.2209 mu M in FISH- tumors, P<0.0001). Dacomitinib growth inhibition was associated with a significant and dose-dependent decline in phosphorylated HER2/neu and S6 transcription factor and a dose-dependent and time-dependent cell cycle arrest in G0/G1 in FISH+ USC. Dacomitinib is remarkably effective against chemotherapy-resistant HER2/neu gene-amplified USC. Clinical studies with dacomitinib in HER2/neu FISH+ USC patients resistant to standard salvage chemotherapy are warranted