Title p53 protein, MAPK i topoizomeraza II α u seroznim karcinomima jajnika Title (english) p53 protein, MAPK and topoisomerase II α in serous ovarian carcinomas Author Dinka Šundov Mentor Snježana Tomić (mentor)Committee member Eduard Vrdoljak (predsjednik povjerenstva)Committee member Stanko Jukić (član povjerenstva)Committee member Tomislav Strinić (član povjerenstva)Granter University of Split Defense date and country 2013, Croatia Scientific / art field, BIOMEDICINE AND HEALTHCARE Universal decimal classificationUDC ) 616 - Pathology. Clinical medicine Abstract Cilj istraživanja. Cilj ovog istraživanja bio je utvrditi razinu imunohistokemijske ispoljenosti p53 proteina, MAPK i topoizomeraze IIα u seroznim karcinomima jajnika niskog i visokog gradusa, te utvrditi njihovu povezanost sa kliničko-patološkim prognostičkim pokazateljima, dužinom slobodnog intervala bez bolesti i ukupnim preživljenjem te odgovorom na kemoterapiju.
Materijali i metode. U istraživanje je uključena 81 bolesnica sa seroznim karcinomom jajnika, operirana u razdoblju od 1995. do 2005. godine. Uzorci tumora bojani su imunohistokemijski primjenom protutijela za p53, MAPK i topo IIα. Učinjena je i KRAS/BRAF mutacijska analiza na uzorcima 73 tumora.
Rezultati. Deset bolesnica (12.3%) dijagnosticirano je u ranom kliničkom stadiju bolesti. Od 81 seroznog karcinoma, 13.6% morfološki je odgovaralo karcinomu niskog gradusa (tip I tumori), a 86.4% karcinomu visokog gradusa (tip II tumori). Serozni karcinomi niskog i visokog gradusa statistički se značajno razlikuju prema imunohistokemijskom izražaju p53 proteina (P=<0.001), MAPK (P=0.003), i topoizomeraze IIα (P=0.001). Pozitivna imunohistokemijska reakcija na p53 protein nađena u 85.7% karcinoma visokog gradusa i u niti jednom karcinomu niskog gradusa. Mutacija KRAS gena nađena je u 54.5% karcinoma niskog gradusa i u samo 13.8% karcinoma visokog gradusa (P=0.006). BRAF mutacija nije nađena ni u jednom uzorku. Pozitivan MAPK izražaj bio je prisutan u dva od pet uzoraka niskog gradusa i u 11 od 54 uzorka visokog gradusa koji su bili negativni na KRAS mutaciju, što govori u prilog činjenici da aktivacija MAPK signalnog puta nije isključivo vezana uz KRAS mutaciju. Kod sedam (11.7%) uzoraka karcinoma koji su morfološki odgovarali karcinomima visokog gradusa, zabilježili smo i mutaciju KRAS gena koja je obilježje puta karcinogeneze tip I i pozitivan imunohistokemijski izražaj p53 proteina, obilježje puta karcinogeneze tip II. U pet od sedam ovih uzoraka nađeni su i morfološki dijelovi koji odgovaraju seroznom borderline tumoru i/ili seroznom karcinomu niskog gradusa.
Prema rezultatima uninominalne analize, klinički stadij bolesti (P=0.007) i pozitivan imunohistokemijski izražaj MAPK proteina (P=0.027) vezani su uz duži slobodni interval bez bolesti (DSF), dok su dob bolesnica iznad 60 godina (P=0.044), veličina
ostatnog tumora (P<0.001), nalaz vaskularne invazije (P=0.002), viši gradus tumora (P=0.025) te klinički stadij III-IV (P=0.010) povezani s kraćim ukupnim preživljenjem (OS). Prema rezultatima multinominalne analize, ostatni tumor (P<0.001) i vaskularna invazija (P=0.084) nezavisni su predskazatelji kraćeg preživljenja bolesnica sa seroznim karcinomom jajnika, dok su se klinički stadij bolesti (P=0.004) i pozitivan imunohistokemijski izražaj MAPK proteina (P=0.077) potvrdili kao nezavisni predskazatelji slobodnog intervala bez povrata bolesti. Imunohistokemijski izražaj p53 proteina, MAPK i topoizomeraze IIα nije povezan s odgovorom na kemoterapiju temeljenu na platini. Bolesnice sa MAPK negativnim karcinomom i potpunim odgovorom na prvu liniju kemoterapije imaju kraće vrijeme do pojave recidiva bolesti (P=0.060).
Zaključak: Iako je istraživanje ograničeno malim brojem seroznih karcinoma niskog gradusa, dokazali smo da se karcinomi niskog i visokog gradusa značajno razlikuju prema imunohistokemijskom izražaju p53 proteina, MAPK, i topoizomeraze IIα te se imunohistokemijsko bojanje na navedene biljege može koristiti u razdvajanju morfološki dvojbenih uzoraka. Postoje morfološka, imunohistokemijska i molekularna prekapanja između ove dvije skupine karcinoma, koja upućuju na mogućnost transformacije karcinoma niskog gradusa u karcinome visokog gradusa, vjerojatno potaknuta mutacijom p53 gena. Razdvajanje seroznih karcinoma jajnika u dvije grupe u budućnosti bi trebalo utjecati na potencijalne metode prevencije i probira, uz različit pristup liječenju bolesnica sa seroznim karcinoma jajnika niskog i visokog gradusa.
Abstract (english) Background: The aim of this study was to assess the immunohistochemical expression of p53, MAPK and topoisomerase II alpha in ovarian serous carcinomas (OSCs), and their relation with clinicopathological prognostic factors, disease free and overall survival and chemotherapy response.
Methods: The study included 81 patients with OSCs who underwent surgery between 1995 and 2005. Formalin fixed paraffin embedded tumour sections were reviewed and examined immunohistochemically using antibodies against p53, MAPK and topoII alpha. KRAS and BRAF mutational analysis was performed on 73 available microdissected samples.
Results: Ten patients (12.3%) were diagnosed in early stage of disease. Of 81 cases of OSCs, 13.6% were of low-grade (Type I) and 86.4% were of high-grade (Type II) morphology. We have found statistically significant differences in the immunohistochemical expression of p53 (P=<0.001), MAPK (P=0.003) and topo IIα (P=0.001) between these two groups. In the high-grade group, 85.7% of cases showed positive p53 immunoexpression, but none of the low-grade samples was p53 positive. KRAS mutation was found in 54.5% of low-grade and 13.8% of high-grade OSCs (P=0.006). None of the samples had BRAF mutation. MAPK positivity showed two of five low-grade carcinomas and 11 of 54 high-grade carcinomas with wild-type KRAS, suggesting that activation of MAPK pathway is not ultimately related to KRAS mutation. We identified seven (11.7%) high-grade samples that showed both KRAS mutation, which is a hallmark of Type I pathway of carcinogenesis, and p53 immunopositivity, which is a hallmark of Type II pathway. In five of seven high-grade samples we have found elements of serous borderline tumour and/or low-grade serous carcinoma. On uninominal analysis, early FIGO stage (P=0.007) and positive MAPK immunoexpression (P=0.027) were significantly associated with longer disease free survival (DFS), while age over 60 (P=0.044), residual disease (P<0.001), vascular invasion (P=0.002), high-grade morphology (P=0.025) and FIGO stage III-IV (P=0.010) were related to significantly shorter overall survival (OS).
Multinominal analysis revealed that residual disease (P<0.001) and vascular invasion (P=0.084) were independent predictors of shorter survival, while early FIGO stage (P=0.004) and positive MAPK immunoexpression (P=0.077) were independent predictors of disease free survival. Positive p53, MAPK and topo IIα immunoexpression was not associated with response to platinum-based chemotherapy. Patients with MAPK negative carcinomas and complete response to first-line chemotherapy have significantly shorter disease free interval (P=0.060).
Conclusions: Although this study is limited by its humble number of low-grade samples, we have found statistically significant differences in the immunohistochemical expression of p53, MAPK and topo IIα between low-grade and high-grade carcinomas, therefore immunohistochemical staining with these markers could be a useful additional tool in distinguishing morphologically questionable samples. There are morphological, immunohistochemical and molecular overlaps between these two groups, which indicate the possibility of transformation of low-grade into high-grade carcinomas, probably triggered by p53 gene mutation. Separation of ovarian serous carcinomas in two groups in the future should influence the potential methods of prevention and screening, with a different approach to treatment of patients with low-grade and high-grade serous carcinomas.
Keywords
Novotvorine jajnika
p53 geni
Antigeni novotvorina
Keywords (english)
Ovarian Neoplasms
p53 Genes
Neoplasm Antigens
Language croatian URN:NBN urn:nbn:hr:171:921465 Study programme Title: Basic and clinical medical sciences Type of resource Text File origin Born digital Access conditions Open access Terms of use Created on 2023-06-02 06:29:58
