Interleukin-6 (IL-6) is a multifunctional regulator of immune response and hematopoiesis. Recently, it has been reported that expression of IL-6 is correlated with prognosis in various cancer patients. In this study, we investigated whether the proliferation and invasion potential of head and neck squamous cell carcinomas (HNSCCs) were influenced by IL-6. All HNSCC cell lines, HEp-2, HSC-2, HSC-4, and SAS, were tested by reverse transcription-polymerase chain reaction (RT-PCR) and expressed the IL-6 receptor (IL-6R), and glycoprotein 130, which is responsible for signal transduction. HEp-2, HSC-2, and HSC-4 also produced IL-6. IL-6 inhibited the proliferation of HSC-2 and SAS, but the invasion potential of all the cell lines increased. Moreover, IL-6 down-regulated soluble IL-6R expression. Anti-IL-6R antibody abrogated the inhibited proliferation and increased invasion induced by IL-6. IL-6 stimulation also induced the extracellular regulated protein kinase 1/2 activation and increased vascular endothelial growth factor release. These results suggest that IL-6 can directly influence cell proliferation and the invasion potential as the first step of tumor metastasis.

We have treated seven patients with a plunging ranula during the past 10 years. All patients underwent surgery via a cervical approach. In two, the ranula reached the anterior neck by passing through a dehiscence in the mylohyoid muscle, while in the other five the plunging ranula passed posteriorly to the mylohyoid muscle. A pseudocyst was extirpated in each patient. Although total sublingual gland excision was not performed in two patients, no recurrence was observed in any patient. Incision of the pseudocyst facilitated subsequent procedures and decreased the incidence of transient facial paralysis. In the presence of a cervical mass without swelling of the oral floor, a cervical approach may still be the method of choice either for the first operation or for salvage surgery after recurrence subsequent to intraoral procedures. It is based on the fact that there may be ectopic sublingual glands residing on the inferior surface of the mylohyoid muscle.

We immunohistochemically identified proliferating cells in the olfactory epithelium of mice, using an anti-proliferating cell nuclear antigen (PCNA) antibody, an anti-Ki67 antibody, an anti-5-bromo-2'-deoxyuridine (BrdU) antibody, and an anti-cyclin D antibody. Positive cells stained by the 4 antibodies were identified mainly in the basal layer. The mean numbers of positive cells stained by the 4 antibodies in 500 olfactory epithelium cells from each animal were as follows: PCNA-positive cells 42, Ki67-positive cells 23, BrdU-positive cells 13.7, and cyclin D1-positive cells 9.2. PCNA may be detected in both proliferating and resting cells. Ki67 is an intranuclear antigen expressed in proliferating, but not resting, cells. Anti-BrdU antibodies might stain proliferating cells only following the S-phase, but not the G1-phase. Cyclin D1 is a protein that works during the G1-phase of the cell cycle. When we stain proliferating cells using proliferating cell markers, it is important to consider the cell cycle phases during which each marker stains.

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