Emiko Sugawara

KLC1-ALK: A Novel Fusion in Lung Cancer Identified Using a Formalin-Fixed Paraffin-Embedded Tissue Only

The promising results of anaplastic lymphoma kinase (ALK) inhibitors have changed the significance of ALK fusions in several types of cancer. These fusions are no longer mere research targets or diagnostic markers, but they are now directly linked to the therapeutic benefit of patients. However, most available tumor tissues in clinical settings are formalin-fixed and paraffin-embedded (FFPE), and this significantly limits detailed genetic studies in many clinical cases. Although recent technical improvements have allowed the analysis of some known mutations in FFPE tissues, identifying unknown fusion genes by using only FFPE tissues remains difficult. We developed a 5′-rapid amplification of cDNA ends-based system optimized for FFPE tissues and evaluated this system on a lung cancer tissue with ALK rearrangement and without the 2 known ALK fusions EML4-ALK and KIF5B-ALK. With this system, we successfully identified a novel ALK fusion, KLC1-ALK. The result was confirmed by reverse transcription-polymerase chain reaction and fluorescence in situ hybridization. Then, we synthesized the putative full-length cDNA of KLC1-ALK and demonstrated the transforming potential of the fusion kinase with assays using mouse 3T3 cells. To the best of our knowledge, KLC1-ALK is the first novel oncogenic fusion identified using only FFPE tissues. This finding will broaden the potential value of archival FFPE tissues and provide further biological and clinical insights into ALK-positive lung cancer.

Identification of anaplastic lymphoma kinase fusions in renal cancer: large-scale immunohistochemical screening by the intercalated antibody-enhanced polymer method.

Several promising molecular‐targeted drugs are used for advanced renal cancers. However, complete remission is rarely achieved, because none of the drugs targets a key molecule that is specific to the cancer, or is associated with “oncogene addiction” (dependence on one or a few oncogenes for cell survival) of renal cancer. Recently, an anaplastic lymphoma kinase (ALK) fusion, vinculin‐ALK, has been reported in pediatric renal cell carcinoma (RCC) cases who have a history of sickle cell trait. In this context, ALK inhibitor therapy would constitute a therapeutic advance, as has previously been demonstrated with lung cancer, inflammatory myofibroblastic tumors, and anaplastic large cell lymphomas.

Pulmonary Inflammatory Myofibroblastic Tumor Expressing a Novel Fusion, PPFIBP1–ALK: Reappraisal of Anti-ALK Immunohistochemistry as a Tool for Novel ALK Fusion Identification

Purpose: The anaplastic lymphoma kinase (ALK) inhibitor crizotinib has been used in patients with lung cancer or inflammatory myofibroblastic tumor (IMT), both types harboring ALK fusions. However, detection of some ALK fusions is problematic with conventional anti-ALK immunohistochemistry because of their low expression. By using sensitive immunohistochemistry, therefore, we reassessed “ALK-negative” IMT cases defined with conventional immunohistochemistry (approximately 50% of all examined cases). Experimental Design: Two cases of ALK-negative IMT defined with conventional anti-ALK immunohistochemistry were further analyzed with sensitive immunohistochemistry [the intercalated antibody-enhanced polymer (iAEP) method]. Results: The two “ALK-negative” IMTs were found positive for anti-ALK immunohistochemistry with the iAEP method. 5′-rapid amplification of cDNA ends identified a novel partner of ALK fusion, protein-tyrosine phosphatase, receptor-type, F polypeptide-interacting protein-binding protein 1 (PPFIBP1) in one case. The presence of PPFIBP1–ALK fusion was confirmed with reverse transcriptase PCR, genomic PCR, and FISH. We confirmed the transforming activities of PPFIBP1–ALK with a focus formation assay and an in vivo tumorigenicity assay by using 3T3 fibroblasts infected with a recombinant retrovirus encoding PPFIBP1–ALK. Surprisingly, the fusion was also detected by FISH in the other case. Conclusions: Sensitive immunohistochemical methods such as iAEP will broaden the potential value of immunohistochemistry. The current ALK positivity rate in IMT should be reassessed with a more highly sensitive method such as iAEP to accurately identify those patients who might benefit from ALK-inhibitor therapies. Novel ALK fusions are being identified in various tumors in addition to IMT, and thus a reassessment of other “ALK-negative” cancers may be required in the forthcoming era of ALK-inhibitor therapy. Clin Cancer Res; 17(10); 3341–8. ©2011 AACR.

Differential expression of Toll-like receptors in follicular lymphoma, diffuse large B-cell lymphoma and peripheral T-cell lymphoma

Although Toll-like receptors (TLRs) in mammals are well-known to play important roles in innate immunity, newer roles for the TLRs have suggested that cells with aberrant TLR expression may have a survival advantage over normal cells. Lymphocytes are one of a small number of cell types that express many of the TLRs, suggesting that abnormal TLR levels/signaling may potentially influence the progression of malignant lymphomas. Thus, frozen samples of 51 lymph nodes from patients with follicular lymphoma (FL), diffuse large B-cell lymphoma (DLBCL) and peripheral T-cell lymphoma (PTCL) were analyzed for the expression of TLR1 to 9 using quantitative real-time PCR, and compared to those in reactive lymphadenopathy (RL) samples. TLR2 was over-expressed in both DLBCL and PTCL but not in FL when compared to RL. TLR1 and TLR4 expression was up-regulated in PTCL, while TLR8 was highly expressed in DLBCL. Although TLR5 showed lower expression in FL, expression of TLR3, TLR6, TLR7 and TLR9 did not vary significantly between different lymphoma subtypes. Double immunostaining revealed an increase in the number of TLR2 and/or TLR8 expressing lymphoma cells in DLBCL. In PTCL, TLR2 and TLR4 expression was localized to neoplastic T cells. TLR expression is highly variable among lymphoma subtypes. However, despite this some significant differences exist that may prove useful in the development of novel therapeutic strategies.

Prognostic significance of HOXB4 in de novo acute myeloid leukemia

Abstract As research into hematopoiesis advances, new factors associated with hematopoietic stem cell (HSC) activity have been discovered, and the contribution of HSC factors to hematopoiesis is now actively being investigated. Since the involvement of stem cells is considered to be important in hematological malignancies as well as normal hematopoiesis, we examined the expression of newly defined HSC factors including HOXB4, TCFEC, HMGB-1, FOS, and SPI-1 in the bone marrow (BM) from de novo acute myeloid leukemia (AML) patients. Expression levels of mRNA extracted from frozen specimens of AML patients and normal controls were measured by real-time polymerase chain reaction (PCR). Among the HSC factors, HOXB4 exhibited significantly higher expression in the BM of AML as compared with normal controls. Immunostaining for HOXB4 revealed that the HOXB4-positive cell ratios correlated well with the expression levels of mRNA for HOXB4 in AML BM. Based on the HOXB4-positive cell ratio, AML patients were divided into two groups (cases with higher ratios and lower ratios). The group with higher HOXB4-positive cell ratios had better prognoses as compared with the group with lower ratios. Multivariate analysis confirmed the HOXB4-positivity as an independent predictor of overall survival of AML patients. Lastly, mRNA expression levels for HOXB4 were inversely correlated with the expression levels of at least two genes, including ABCB1, which is known to be a multidrug-resistance gene. Our study distinguishes a subgroup of AML with higher HOXB4 expression and better prognosis, and this might be reflected by relative drug sensitivity in leukemic cells.

Giant cell carcinoma causing rapidly progressive respiratory failure as the presenting feature of AIDS

The incidence of lung cancer has been increasing among HIV-positive patients. The majority of these cases were in patients previously diagnosed as HIV-positive and treated with highly active antiretroviral therapy (HAART). Here, we report a 56-year-old male patient with lung cancer, who was diagnosed as HIV-positive after the onset of neck pain and lumbago and thus, was not treated with anti-AIDS therapy. The patient developed rapidly progressive and fatal respiratory failure. Autopsy demonstrated giant cell carcinoma of the lung responsible for carcinomatous lymphangitis. This case highlighted the possibility that pulmonary carcinogenesis in HIV-positive patients is not necessarily associated with HAART therapy.

An Autopsy Case of Dementia with Lewy Bodies with Vocal Cord Abductor Paralysis

cal – chest XP and CT revealed no lesion affecting the recurrent and/or vagus nerves. The family’s consent to perform tracheotomy was not obtained. At the age of 89, he was admitted to our hospital with pyrexia. On admission, neurological examination revealed new findings including right-sided dominant rigidity and Myerson’s sign. Resting tremor was absent. He showed severe dementia (MMSE 0/30). Moderate-tosevere atrophy of fronto-temporal cortex including hippocampus and ischemic change were revealed on his brain MRI ( fig. 1 a). But brainstem-cerebellar atrophy, hot cross ban sign or abnormal intensity of striatum were absent. On hospital day 34, he died with uncontrolled infection. Brain weight was 1,185 g. Macroscopically, the medial temporal lobe was atrophic, and moderate-to-severe depigmentation was apparent in the substantia nigra and locus ceruleus. Histologically, the brain stem (substantia nigra, locus ceruleus, dorsal motor nucleus of the vagus, raphe nuclei) was moderately to severely involved with Lewy pathology ( fig. 1 b). Although this pathological change extended to the ambiguus nucleus, the neuronal loss and gliosis of Dear Sir, Vocal cord abductor paralysis (VCAP), frequent in the later stage of multiple systemic atrophy (MSA) [1–5] , is rare in Parkinson’s disease (PD) [5, 8, 9] and exceptional in dementia with Lewy bodies (DLB). Here we report the first autopsy-verified case of DLB with VCAP. The patient felt anxiety at the age of 71, and consulted the psychiatrist of our hospital; mild dementia was diagnosed and minor tranquilizer was prescribed. At the age of 75, he experienced difficulty in playing tennis. Gradually, his walking slowed down. At the age of 76, he had visual hallucination. A neurologist of our hospital noted akinesia, mask-like face and small steppage gait and apparent dementia based on mini-mental state examination (MMSE 21/30). He was diagnosed as having probable DLB based on the clinical criteria [10] .