Judit Olasz

Revealing cancer initiating cells in metastatic melanomas by harnessing the host′s anti tumor humoral immune mechanisms

Results Cell cultures grew out of the great majority of the starter metastatic tissue specimen and cancer initiating cells could be sorted (BD FACSAvia Sorter) by colocalized unique sialilated glycosphingolipids and anti CD20 binding capacity. Characteristic growth pattern, spheroid forming, CSC markers like CD133, Nestin, ABCB5, CD20 and unique GD3 gangliosides were found. Patients′ sera and selected patients′ Epstein Barr Virus transformed cell supernatants in bulk or after limiting dilution cloning were tested for cancer binding by ELISA and immunofluorescence. Our novel tumor infiltrating B cell antibody phage display technique and DNA sequence cluster analysis (Vector NTI Advance 11, Bioedit 7.0, ClustalX2.0.11) resulted in some antibody fragments, belonging to representative tumor binding antibody variable region subgroups, with defined silalilated glycosphingolipid specificity.

Two germline alterations in mismatch repair genes found in a HNPCC patient with poor family history

The Bethesda guidelines may offer more useful criteria in patients’ selection for germline mismatch repair gene mutation analysis than guidelines merely based on family background. An early onset double primary colorectal cancer patient with poor family history with MSI-H status was investigated for MLH1 promoter methylation, expression of the MLH1 and MSH2 gene by immunohistochemistry and mutations in the MLH1 and MSH2 genes. The index patient carried two germline alterations, the p.Val716Met in MLH1 and the c.2210+lG>C in MSH2 genes, and both tumors failed to express MLH1 and MSH2 proteins. After subsequent analysis of the whole family of the index patient, the p.Val716Met variant can be defined as a rare polymorphism with the possible contribution of pathogenicity to tumor formation and c.2210+1G>C as a true pathogenic mutation causing an out-of-frame deletion of exon 13.

Somatic APC Inactivation Mechanisms in Sporadic Colorectal Cancer Cases in Hungary

The role of germline inactivation of the adenomatosis polyposis coli (APC) gene in hereditary colorectal cancer is well known, being the most important cause of familial adenomatosus polyposis (FAP) syndrome. Hereditary cases with germline mutations, however, account only for 5–10% of colorectal cancers. The somatic inactivation of this gene has also been observed in sporadic cases. In order to examine the inactivation mechanisms of the APC gene we screened 70 sporadic colorectal cancer cases (27 rectal, 43 intestinal) of different stages for promoter hypermethylation, allelic imbalance (AI) and somatic mutations. The presence of promoter hypermethylation was observed in 21 cases (30%). Fifteen of the examined tumors (21%) showed AI, and also 15 tumors (21%) carried at least one somatic mutation. Thirteen of the detected alterations were novel variations: seven frameshifts, four missense mutations and two polymorphisms. Biallelic inactivation was found in 15 patients (21%). These results suggest that the inactivation of the APC gene is very common in sporadic colorectal cancer, and the main inactivation mechanism of the APC gene is promoter hypermethylation. Allelic imbalance has the same frequency as mutations, and mutations in the APC gene are more common in the early stages and in tumors located in the rectum.

“Immune B Cells know it better”: tumorimmunological panel assay to define tumor-associated antigen binding antibodies in patients with metastatic melanomas.

Background Revealing novel cancer targeting biomarkers is a great challenge, and especially urging in cancer types with a more pronounced metastatic feature. We focus on potential anti-tumor immune reactions of the host. In order to harness the natural humoral immune response a novel immunological and molecular genetic panel assay has been developed for the investigation of patients with melanomas.

Q48P mutation in the hMLH1 gene associated with Lynch syndrome in three Hungarian families

Lynch syndrome (Hereditary nonpolyposis colorectal cancer, HNPCC) is an inherited disease with variable phenotype causing the development of colon cancer and other malignancies. The basis of the disease is believed to be the mismatch repair gene mutations. Genetic screening has been performed among the patients who have undergone surgery for colon cancer at the University of Debrecen, Department of Surgery. Tumor samples of the screened patients were submitted to immunohistochemistry on hMLH1, hMSH2 and hMSH6 genes, microsatellite instability testing, followed by sequencing and multiple ligation dependent probe amplification. Three families were identified with the missense mutation c.143A>C (p.Q48P) of hMLH1 gene. In one of the families a segregation analysis of this particular variant was also accomplished. The segregation analysis revealed a clear correlation between the tumor cases and the occurrence of this mutation. However, none of the analyzed 100 healthy controls demonstrated the same aberration. There is only one published evidence in the literature about the presence of this rare variant in any population. The Gln to Pro switch in the ATPase domain, a conservative region of the hMLH1 gene, creates significant changes in the protein structure. These results indicate that this mutation is the abnormality responsible for the patients’ phenotype and it is feasible that this particular aberration occurs more frequently among Hungarian Lynch syndrome patients.

A hereditaer nonpolyposus colorectalis carcinoma szindrómás betegek szűrésének és szoros utánkövetésének fontossága egy családfa bemutatása kapcsán

INTRODUCTION Hereditary nonpolyposis colorectal carcinoma (HNPCC) is an autosomal dominant disease, which shows familial clustering. AIM We would like to emphasize the importance of monitoring the HNPCC syndrome patients by presenting a case of a proven MMR gene mutation carrier and her family tree encompassing 10 years. MATERIALS AND METHOD To screen a suspected HNPCC Hungarian family member we are taking thorough family histories. If the diagnosis of HNPCC was further supported by immunohistology and the microsatellite status, sequencing of the MMR genes was carried out. RESULTS A novel mutation in exon 6 of the hMSH2 gene leading to the deletion of two nucleotide pairs [c.969-970delTC] was detected in our patient. During the 10-year follow-up period of our patient new HNPCC-associated tumors have developed in several family members. Conslusion: Close surveillance of the patient and its family members at risk was effective, although it requires compliance from the subjects. Orv Hetil. 2017; 158(30): 1182-1187.Absztrakt: Bevezetes: A hereditaer nonpolyposus colorectalis carcinomara jellemző mutaciok (HNPCC) autoszomalis dominans oroklődesmenetet mutatnak. Leginkabb vastagbeldaganatok kialakulasaert felelősek. Celkitűzes: A HNPCC-szindromas betegek szűresenek es kovetesenek fontossagat szeretnenk hangsulyozni egy igazolt MMR-gen-mutaciot hordozo betegunk jelenlegi es 10 evvel korabbi csaladfajanak osszehasonlitasaval. Betegek es modszer: Hazankban előfordulo, HNPCC-re gyanus csaladok kiszűrese erdekeben alapos csaladi anamnezist veszunk fel. Amennyiben az immunhisztokemiai es mikroszatellitainstabilitas-vizsgalatok HNPCC-szindromara utalnak, elvegezzuk az MMR-genek szekvenalasat. Eredmenyek: Betegunknel egy, a hMSH2-gen 6. exon ket bazispart erintő deletioja (c.969–970delTC) igazolodott. Tizeves utankovetes soran betegunknel es rokonainal ujabb, a HNPCC-re jellemző tumorok jelentek meg. Kovetkeztetes: A veszelyeztetett csaladtagok kovetese soran a szekunder prevencio a jol egyuttműkodő betegeknel hatekony volt. ...

Minor tumor infiltrating B cells opened a door to reveal and eliminate cancer initiating cells in metastatic melanomas

Meeting abstracts The theory and investigations on cancer stem cells (CSCs) have received growing attention, as these cells are responsible for the failure of cancer therapeutic strategies and the return of cancer. A complex tumorimmunological study on primary and metastatic cancerous tissue

Anti-tumor antibody profile analysis to harness the potentials of B cells in melanomas and the natural humoral immune response

Meeting abstracts Natural humoral immune response and autoimmune mechanisms have great importance in keeping the balance of tumorimmunity, although it has not yet been fully understood. We aimed to reveal potential anti-tumor immune response by immunoglobulin (Ig) profile analysis of patients with