Detection of CSF1 gene derangement in 'sclerosing mucoepidermoid carcinoma with eosinophilia' of the parotid gland masquerading as Langerhans cell histiocytosis.

Key Clinical Message: When faced with a slowly enlarging firm mass in the parotid gland accompanied by a histological picture of unusual sclerosis with abundant Langerhans cells and eosinophilic infiltrates, sclerosing mucoepidermoid carcinoma with eosinophilia should be considered as one of the differential diagnoses. Further studies are warranted for accurate diagnosis and appropriate treatment. Abstract: Sclerosing mucoepidermoid carcinoma of the salivary gland with eosinophilia is a rare tumor mostly negative for the MAML2 rearrangement commonly seen in salivary mucoepidermoid carcinoma. It was not listed as an entity in the 2022 WHO Classification of Head and Neck Tumors. We presented one case initially diagnosed as Langerhans cell histiocytosis and recurred as a frankly invasive carcinoma. Molecular studies showed CSF1 gene derangement and provided new understanding concerning the Langerhans cell and eosinophilic reaction. Further molecular studies on this entity would throw light on its oncogenesis and refine its nomenclature.

MicroRNA profiling study reveals miR-150 in association with metastasis in nasopharyngeal carcinoma.

MicroRNAs (miRNAs) are small non-coding RNAs that play a crucial role in pathogenesis of human cancers. Several miRNAs have been shown to involve in nasopharyngeal carcinoma (NPC) pathogenesis through alteration of gene networks. A global view of the miRNA expression profile of clinical specimens would be the best way to screen out the possible miRNA candidates that may be involved in disease pathogenesis. In this study, we investigated the expression profiles of miRNA in formalin-fixed paraffin-embedded tissues from patients with undifferentiated NPC versus non-NPC controls using a miRNA real-time PCR platform, which covered a total of 95 cancer-related miRNAs. Hierarchical cluster analysis revealed that NPC and non-NPC controls were clearly segregated. Promisingly, 10 miRNA candidates were differentially expressed. Among them, 9 miRNAs were significantly up-regulated of which miR-205 and miR-196a showed the most up-regulated in NPC with the highest incidence percentage of 94.1% and 88.2%, respectively, while the unique down-regulated miR-150 was further validated in patient sera. Finally, the in vitro gain-of-function and loss-of-function assays revealed that miR-150 can modulate the epithelial-mesenchymal-transition property in NPC/HK-1 cells and led to the cell motility and invasion. miR-150 may be a potential biomarker for NPC and plays a critical role in NPC tumourigenesis.

IKBB tumor suppressive role in nasopharyngeal carcinoma via NF-κB-mediated signalling.

Tumor suppressor genes (TSGs) play a prominent role in cancer and are important in the development of nasopharyngeal carcinoma (NPC), which is endemic in Southern China as well as Southeast Asia. Apart from TSGs, aberrant signalling pathways are also commonly associated with tumor progression. Unsurprisingly, the NF-κB pathway is frequently associated with angiogenesis and promoting tumor growth and development. Functional complementation studies using microcell-mediated chromosome transfer helped to identify IKBB as a putative TSG in NPC. IKBB, an inhibitor of NF-κB, has recently been shown to be inversely associated with tumor growth and metastasis via inactivation of the NF-κB pathway, but its suppressive role is still only poorly understood. This study takes the lead in revealing the suppressive role of IKBB in NPC. IKBB is silenced in the majority of NPC tumor tissues in all stages. Its suppressive role is substantiated by perturbation in tumor formation, cell migration and angiogenesis. Interestingly, IKBB not only affects the 'seed', but also influences the 'soil' by downregulating the transcriptional level of proangiogenic factors Rantes, Upar, IL6, and IL8. For the first time, our data establish the importance of a novel tumor suppressive IKBB gene in abrogating angiogenesis in NPC via the NF-κB signalling pathway, which is likely mediated by crosstalk with the Akt/Gsk3ß signalling pathway.

LTBP-2 confers pleiotropic suppression and promotes dormancy in a growth factor permissive microenvironment in nasopharyngeal carcinoma.

This study identified LTBP-2 as a pleiotropic tumor suppressor in nasopharyngeal carcinoma, which safeguards against critical malignant behaviors of tumor cells. LTBP-2 expression was significantly decreased or lost in up to 100% of NPC cell lines (7/7) and 80% of biopsies (24/30). Promoter hypermethylation was found to be involved in LTBP-2 silencing. Using a tetracycline-regulated inducible expression system, we unveiled functional roles of LTBP-2 in suppressing colony formation, anchorage-independent growth, cell migration, angiogenesis, VEGF secretion, and tumorigenicity. Three-dimensional culture studies suggested the involvement of LTBP-2 in maintenance of tumor cell dormancy in a growth factor favorable microenvironment.

Pernicious anemia in Chinese: a study of 181 patients in a Hong Kong hospital.

To study the clinical and hematologic features of pernicious anemia in Chinese, we describe 181 Chinese with megaloblastic anemia and low serum cobalamin, in association with either classic Schilling test results (82 patients) or the presence of serum antibody to intrinsic factor (99 patients), encountered in a regional hospital in Hong Kong from May 1994 to May 2005. The median age was 75 years (range, 32-95 yr) and the male to female ratio was 1:1.5. The chief presenting feature was anemia, and fewer than 10% of patients presented predominantly with neurologic deficit. Gastric biopsies of 109 patients showed glandular atrophy in 73, endocrine cell hyperplasia in 5, polyps in 14, adenocarcinoma in 1, and chronic gastritis in the rest. Gastric adenocarcinoma occurred in 1.7% of patients after a median follow-up of 35 months (range, 0.5-132 mo). Diabetes mellitus occurred in 24% of patients and thyroid disease in 7%. No specific ABO blood group was associated with pernicious anemia. Serum antibody to intrinsic factor (73%) occurred more frequently than serum antibody to gastric parietal cell (65%) (p=0.353). The frequency of serum antibody to gastric parietal cell was higher in male (78%) than in female patients (53%) (p=0.018). Pernicious anemia is a major cause of megaloblastic anemia in Chinese.