Cancer Genetics and Cytogenetics 158 (2005) 172–179 Establishment of a cell line from a malignant rhabdoid tumor of the liver lacking the function of two tumor suppressor genes, hSNF5/INI1 and p16 Hiroshi Kuroda a,b, * , Hiroshi Moritake c , Kazumi Sawada c , Yasumichi Kuwahara b , Issei Imoto d , Johji Inazawa d , Tohru Sugimoto b a Department of Pediatrics, Kyoto City Hospital, Kyoto, 1-2 Higashitakada-cho, Mibu, Nakagyo-ku, Kyoto 604-8845, Japan b Department of Pediatrics, Kyoto Prefectural University of Medicine, Kyoto, Japan c Department of Pediatrics, Miyazaki Medical College, Miyazaki, Japan d Department of Molecular Cytogenetics, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan Received 12 July 2004; received in revised form 19 August 2004; accepted 20 August 2004 Abstract Malignant rhabdoid tumors (MRT) of the liver are rare. A few liver MRT cell lines have been established but none has been characterized in detail. Here we describe a new MRT cell line from the liver, which is designated MP-MRT-AN, and describe it in detail. Immunohistochemical assays detected the expression of vimentin and cytokeratin but they were negative for neurofilament, desmin, α-smooth muscle actin, α-sarcomeric actin, and smooth muscle myosin heavy chains SM1 and SM2. RT-PCR assays revealed that this cell line did not express smooth muscle myosin heavy chain isoforms or MyoD1. No aberration was identified in 22q by G-banded analysis; however, the hSNF5/ INI1 gene, a suppressor gene of MRT that maps to 22q11.2, was homozygously deleted from exons 1 to 5 in this cell line. Furthermore, the expression of another tumor suppressor gene, p16 (CDKN2A), was not detected by RT-PCR. This raises the possibility that the aggressive phenotype of malignant rhabdoid tumors is caused by the loss of two or more tumor suppressor genes.  2005 Elsevier Inc. All rights reserved. 1. Introduction Malignant rhabdoid tumor (MRT) is a rare and very ag- gressive neoplasm of childhood. MRT was first reported as an unfavorable histologic type of renal tumor, a variant of Wilms’ tumor [1], and was thought to be restricted to the kidneys. However, it has also been reported to arise from extrarenal sites, including the central nervous system, neck, chest, abdomen, liver, and other regions [2,3]. Among these types of MRT, that of the liver is rare [4–11]: no cell lines derived from patients with MRT of the liver have been well characterized. Several tumor suppressor genes play important roles in the prevention of oncogenesis in many tumors. The hSNF5/ INI1 gene, located at 22q11.2, has been reported recently as a tumor suppressor gene of MRT [12–15]. On the other hand, the p16 (CDKN2A) gene, also known as MTS1, is * Corresponding author. Tel.: +81-75-311-5311; fax: +81-75-321-6025. E-mail address: hkuroda@hosp.city.kyoto.jp (H. Kuroda). 0165-4608/05/$ – see front matter  2005 Elsevier Inc. All rights reserved. doi:10.1016/j.cancergencyto.2004.08.032 inactivated in a significant percentage of melanomas, acute lymphocytic leukemias, glioblastomas, pancreatic adenocar- cinomas, non-small cell lung cancers, and so on [16,17]. It is not known, however, whether p16 is inactivated in MRT. We established a liver MRT cell line, characterized its nature, and investigated its genetic aberrations, especially with respect to tumor suppressor genes. We found that the functions of two tumor suppressor genes, hSNF5/INI1 and p16, were lost in this cell line. To our knowledge, this is the first detailed report of a liver MRT cell line. 2. Materials and methods 2.1. Clinical history of the patient A 3-month-old Japanese female was admitted to our hos- pital with respiratory distress on October 15, 1996. Chest x-ray revealed a massive pleural effusion, and computed tomography of the abdomen showed the main tumor in the left lobe of the liver and several small tumors in the right lobe (Fig. 1). Cytologically, tumor cells in the pleural