Targeting EGFR and HER-2 with cetuximab- and trastuzumab-mediated immunotherapy in oesophageal squamous cell carcinoma

We previously reported that oesophageal squamous cell carcinoma (SCC) had a relatively high incidence of EGFR and HER-2 overexpression. Thus, anti-HER family targeting may become a promising approach to treat oesophageal SCC. In the present study, we investigated (a) the distribution of EGFR and HER-2 expression in oesophageal SCC (n=66) detected by immunohistochemistry and (b) cetuximab- and/or trastuzumab-mediated biological activity (antiproliferative effect by the MTT assay, apoptosis-inducing activity by the annexin V/propidium iodide assay, and antibody-dependent cellular cytotoxicity (ADCC) by the ⁵¹Cr-release assay) against oesophageal SCC cell lines with various levels of EGFR and HER-2. Twelve of the 66 patients (18%) showed both EGFR- and HER-2 expression. Out of both EGFR- and HER-2-positive cases, nine cases (75%) showed EGFR and HER-2 expression in individually distinct regions. Furthermore, the combination of cetuximab and trastuzumab could induce synergistic antiproliferative effects and additional ADCC activities against not all, but several oesophageal SCC cell lines with EGFR and HER-2 expression. The combination of cetuximab and trastuzumab may be useful in the treatment of oesophageal SCC with EGFR and HER-2 expression.

Frequencies of HER-2/neu expression and gene amplification in patients with oesophageal squamous cell carcinoma

The utilisation of antitumour T cells induced by cancer vaccination with HER-2 peptides or antibodies (Herceptin) against HER-2, as immunotherapy for oesophageal cancer, is a novel and attractive approach. It is important to clarify the frequencies of HER-2 expression and gene amplification in patients with oesophageal squamous cell carcinoma (SCC) and to evaluate the relationship between HER-2 status and HLA haplotype, since the candidates for HER-2 peptide-based vaccination are restricted to a certain HLA haplotype. We determined the frequency of HER-2 expression using the HercepTest for immunohistochemistry and HER-2 gene amplification by fluorescence in situ hybridisation (FISH) assay in oesophageal SCC (n=66). HER-2-positive tumours (1+/2+/3+) analysed by a HercepTest were observed in 30.3% of all the patients and HER-2 gene amplification evaluated by FISH was observed in 11.0% of all the patients, in which all HercepTest (3+) tumours were found to have gene amplification and three of six moderately positive (2+) tumours showed gene amplification. Furthermore, HER-2-positive cells were present more diffusely and were larger within each tumour in the patients who were HercepTest 3+ than those who were HercepTest 1+. Moreover, the survival rate in HER-2-positive group was significantly worse than that in HER-2-negative group. Also, the survival rate in the patients with HER-2 gene amplification was significantly worse than that without HER-2 gene amplification. In addition, oesophageal SCC patients with both HLA-A24-positive and HER-2-positive tumours (1+/2+/3+) accounted for 26% of these cases, and both HLA-A2- and HER-2-positive tumours accounted for 18% of them.

In situ interleukin-6 transcription in embryonic nonmuscle myosin heavy chain expressing immature mesenchyme cells of cardiac myxoma

Cardiac myxomas are benign tumors which sometimes secrete interleukin-6 (IL-6), however, the pathogenesis and the IL-6 secreting cells are not clear. There are vascular myosin heavy chain isoforms; SM2 expression is specific to mature smooth muscle cells, while SMemb is a nonmuscle-type isoform which is expressed in immature mesenchyme cells. We hypothesized that immature mesenchyme cells play pivotal roles in the secretion of IL-6; we studied these expression in resected samples of myxoma. SMemb expression was increased but SM2 expression was not in the channels of myxoma. Increased IL-6 transcription was observed in the SMemb expressing cells in the channel. Therefore, mesenchyme cells with immature phenotype in the channel play pivotal roles of inflammation and pathogenesis of cardiac myxoma.

Points to note from indications for heart transplantation to post-heart transplant care: from the care of patients with refractory heart failure and overseas heart transplantation

To examine important points surrounding the indications for heart transplantation (HTX) to care after HTX, we reviewed 22 patients with refractory heart failure aged less than 60 years who had been observed for the past 6 years. Sixteen patients had dilated cardiomyopathy; 1, dilated hypertrophic cardiomyopathy; 3, restrictive cardiomyopathy; and 2, ischemic cardiomyopathy; there were 15 males and 7 females, and 6 of the 22 patients were children. The 22 patients were divided into two groups according to their response to tailored medical therapy. Group 1 (n = 6) consisted of those whose cardiac function improved to New York Heart Association (NYHA) status 2 from NYHA status 3 or 4. Group 2 (n = 16) still exhibited refractory heart failure. Seven of these 16 patients went on to have successful HTX. Survival in groups 1 and 2 combined was significantly lower than actuarial survival post-HTX cited in the registry of the International Society for Heart and Lung Transplantation, and group 2 had an even lower survival than the total groups 1 and 2 survival. Survival in children was much lower than that in adults. Seven of the 16 patients in group 2 showed a genetic link, but there was no genetic link in group 1 patients. One patient in group 2 had a panel reactive antibody (PRA) value of 46% and died while awaiting HTX. Post-HTX care in terms of immunosuppressant therapy, was modified for each patient. It is particularly necessary to consider the time a patient will wait on the list for candidates for HTX who are children, have a genetic link, or are positive for PRA. A genetic approach is helpful to determine indications for HTX. Sensitive monitoring of post-HTX immunosuppression is needed.