J. M. Nesland

Clinicopathological associations of CD44 mRNA and protein expression in primary breast carcinomas

Aims:u2002 The purpose of this study was to examine the occurrence of CD44 isoforms in breast carcinomas and their role in predicting clinical outcome.

B7-H3 expression in colorectal cancer: Nuclear localization strongly predicts poor outcome in colon cancer

In colorectal cancer there is a need for molecular markers that can complement the histopathological staging in predicting the likelihood of disease recurrence following curatively intended surgery. B7‐H3 is an immunoregulatory protein shown to be overexpressed in several cancer forms, often associated with more advanced disease and poor prognosis. We wanted to examine whether B7‐H3 could be a potential prognostic marker in colorectal cancer. Paraffin‐embedded samples from 277 colorectal cancer patients were immunostained with anti‐B7‐H3 antibody. B7‐H3 was expressed in the tumor cell cytoplasm and cell membrane in 62% and 46% of the samples, respectively. Unexpectedly, B7‐H3 was expressed in the nucleus in 30% of the tumors. The nuclear localization was confirmed by Western immunoblotting of subcellular fractions. Importantly, in colon cancer, nuclear B7‐H3 expression was independently and significantly associated with reduced metastasis‐free, disease‐specific and overall survival. B7‐H3 expression in tumor‐associated vasculature and fibroblasts was observed in the majority of samples, and endothelial B7‐H3 expression was also significantly associated with poor outcome in colon cancer. In rectal cancer patients, the only significant association was between fibroblast B7‐H3 expression and shorter metastasis‐free survival. Few significant associations to clinicopathological parameters were seen. The results indicate that nuclear B7‐H3 might be involved in colon cancer progression and metastasis, and suggest that nuclear B7‐H3 could become a useful prognostic marker in colon cancer.

Notch1 is a 5-fluorouracil resistant and poor survival marker in human esophagus squamous cell carcinomas.

Notch signaling involves the processes that govern cell proliferation, cell fate decision, cell differentiation and stem cell maintenance. Due to its fundamental role in stem cells, it has been speculated during the recent years that Notch family may have critical functions in cancer stem cells or cancer cells with a stem cell phenotype, therefore playing an important role in the process of oncogenesis. In this study, expression of Notch family in KYSE70, KYSE140 and KYSE450 squamous esophageal cancer cell lines and virus transformed squamous esophageal epithelial cell line Het-1A was examined by quantitative RT-PCR. Compared to the Het-1A cells, higher levels of Nocth1 and Notch3 expression in the cancer cell lines were identified. Due to the finding that NOTCH3 mainly mediates squamous cell differentiation, NOTCH1 expression was further studied in these cell lines. By Western blot analyses, the KYSE70 cell line which derived from a poorly differentiated tumor highly expressed Notch1, and the Notch1 expression in this cell line was hypoxia inducible, while the KYSE450 cell line which derived from a well differentiated tumor was always negative for Notch1, even in hypoxia. Additional studies demonstrated that the KYSE70 cell line was more 5-FU resistant than the KYSE450 cell line and such 5-FU resistance is correlated to Notch1 expression verified by Notch1 knockdown experiments. In clinical samples, Notch1 protein expression was detected in the basal cells of human esophagus epithelia, and its expression in squamous cell carcinomas was significantly associated with higher pathological grade and shorter overall survival. We conclude that Notch1 expression is associated with cell aggressiveness and 5-FU drug resistance in human esophageal squamous cell carcinoma cell lines in vitro and is significantly associated with a poor survival in human esophageal squamous cell carcinomas.

Assessment of long term radiotoxicity after treatment with the low dose rate {alpha}-particle emitting radioimmunoconjugate 227Th-rituximab

PurposeThe anti-CD20 antibody rituximab labelled with the α-particle-emitting radionuclide 227Th is of interest as a radiotherapeutic agent for treatment of lymphoma. Complete regression of human lymphoma Raji xenografts in 60% of mice treated with 200xa0kBq/kg 227Th-rituximab has been observed. To evaluate possible late side effects of 227Th-rituximab, the long-term radiotoxicity of this potential radiopharmaceutical was investigated.MethodsBALB/c mice were injected with saline, cold rituximab or 50, 200 or 1,000xa0kBq/kg 227Th-rituximab and followed for up to 1xa0year. In addition, nude mice with Raji xenografts treated with various doses of 227Th-rituximab were also included in the study. Toxicity was evaluated by measurements of mouse body weight, white blood cell (WBC) and platelet counts, serum clinical chemistry parameters and histological examination of tissues.ResultsOnly the 1,000xa0kBq/kg dosage resulted in decreased body weight of the BALB/c mice. There was a significant but temporary decrease in WBC and platelet count in mice treated with 400 and 1,000xa0kBq/kg 227Th-rituximab. Therefore, the no-observed-adverse-effect level (NOAEL) was 200xa0kBq/kg. The maximum tolerated activity was between 600 and 1,000xa0kBq/kg. No significant signs of toxicity were observed in histological sections in any examined tissue. There were significantly (pu2009<u20090.05), but transiently, higher concentrations of serum bile acids and aspartate aminotransferase in mice treated with either 227Th-rituximab or non-labelled antibody when compared with control mice. The maximum tolerated dose to bone marrow was between 2.1 and 3.5xa0Gy.ConclusionTherapeutically relevant dose levels of 227Th-rituximab were well tolerated in mice. Bone marrow suppression, as indicated by decrease in WBC count, was the dose-limiting radiotoxicity. These toxicity data together with anti-tumour activity data in a CD20-positive xenograft mouse model indicate that therapeutic effects could be obtained with relatively safe dosage levels of the radioimmunoconjugate.

High expression of the cysteine proteinase legumain in colorectal cancer – Implications for therapeutic targeting

BACKGROUNDnThe cysteine proteinase legumain is highly expressed in cancer. Legumain is a potential biomarker and has been suggested to be utilised for prodrug activation in cancer therapy. However, to define the suitability of legumain for such purposes, detailed knowledge of cell type-specific and subcellular expression together with proteolytic activity patterns in tumour tissue is necessary.nnnMETHODSnExpression of legumain was examined in a panel of 277 primary tumours from colorectal cancer (CRC) patients using immunohistochemistry. Tumour (cytoplasmic diffuse, cytoplasmic granulated, and nuclear) and stromal cell expression of legumain was quantified, and associations with clinicopathological parameters and outcome were analysed. Additionally, normal colon tissue and spontaneous mouse tumours were stained for legumain.nnnRESULTSnLegumain was highly expressed in tumour and stromal cells. Nuclear legumain was detected in 30% of the tumours. In colon cancer patients, high legumain expression was associated with overall and metastasis-free survival (OS; MFS) in uni- and multivariate analysis. Nuclear legumain was associated with poor OS, but not MFS in the colon cancer subgroup. Cytoplasmic granulated or diffuse expression was not associated with OS or MFS. Normal epithelial cells exhibited granulated legumain mainly at the apical pole, and legumain was highly expressed in CD68 positive macrophages.nnnCONCLUSIONSnLegumain is a highly expressed proteinase in CRC and associated with poor outcome in colon cancer. Diversified localisation of legumain expression in tumour and stromal cells suggests multiple functions in CRC, representing both a challenge and an opportunity for use in therapeutic targeting.

Adenocarcinomas on the rise--does it influence survival from oesophageal cancer?

Background and Aims: A significant change in the occurrence of oesophageal squamous cell carcinomas (SCCs) in relation to adenocarcinomas (ACs) has been observed in the Norwegian population during the last 20 years (1988–2007). The AC incidence has increased from 5–10% to more than 50% nowadays, while the incidence of SCCs has decreased. Our goal was to evaluate if the change from SCC to AC and the increased effort to control reflux could be reflected in tumour stage, patient demographics and treatment results. Material and Methods: We analysed clinical and pathological data from 347 patients with oesophageal AC (n = 189) and SCC (n = 158) treated at The Norwegian Radium Hospital during said period for patient- and tumour characteristics, treatment modalities and survival. Results: An oesophageal resection was performed in 169 of 347 patients. The median survival rate for all patients was 15 months, with a 5-year survival rate of 10%. The median survival time for operated and non-operated patients was 25 and 12 months respectively, with the corresponding 5-year survival rate of 13% and 2%. Patients with N0M0 disease operated with free resection margins presented a 5-year survival rate of 28%. Conclusions: The change from SCC to AC and the ensuing considerable efforts made in surveillance and treatment of AC did not lead to improved long time survival for our patients.