Keiichi Arakaki

PDGF α receptor is a mediator for Cisplatin-induced Met expression.

For decades, platinum drugs have been the mainstay of cancer treatment. However, over time, drug resistance develops, leaving few treatment options. Here we show that platelet-derived growth factor α receptor (PDGF α receptor)-mediated signaling plays a key role in hepatocyte growth factor (HGF) receptor (c-Met) upregulation, which in turn is thought to play an important role in chemotherapy resistance. PDGF α receptor inhibition eliminates cisplatin-dependent Met expression in cervical cancer cell lines. PDGF α receptor inhibitors are widely used in clinical settings, suggesting that the clinical translation of our findings could reduce the suffering of people from drug resistance.

Articulation disorders associated with maxillary growth after attainment of normal articulation after primary palatoplasty for cleft palate.

Little attention has been given to the connection between maxillary growth and the emergence of articulation disorders among cleft palate patients who previously successfully attained normal articulation after undergoing primary palatoplasty. Follow-up assessment of 22 surgically treated unilateral cleft lip and palate patients who attained normal articulation before school entry revealed that, during mixed dentition, half the patients exhibited palatalized articulation and half retained normal articulation. To determine the possible effect on articulation of growth changes in dental arch dimensions, a comparison was made of deciduous dentition and mixed dentition oral cavity measurements. Indications are that palatalized articulation occurs in patients with a smaller anterior palatal volume, the presence of linguoversion teeth, and poorer growth ability. Results reveal the importance of early management of dental arch dimensions, and the need for periodic assessment and management of articulation even for patients who attain normal articulation subsequent to primary palatoplasty.

HPV16E6-Dependent c-Fos Expression Contributes to AP-1 Complex Formation in SiHa Cells

To date, the major role of HPV16E6 in cancer has been considered to be its ability to inhibit the p53 tumor-suppressor protein, thereby thwarting p53-mediated cytotoxic responses to cellular stress signals. Here, we show that HPV16E6-dependent c-fos oncogenic protein expression contributes to AP-1 complex formation under oxidative stress in SiHa cells (HPV16-positive squamous cell carcinoma of the cervix). In addition, we examined the role of HPV16E6 in TGF-α-induced c-fos expression and found that the c-fos protein expression induced by TGF-α is HPV16E6 dependent. Thus, our results provide the first evidence that HPV16E6 contributes to AP-1 complex formation after both ligand-dependent and independent EGFR activation, suggesting a new therapeutic approach to the treatment of HPV-associated tumors.

Malignant Pheochromocytoma with Mandibular Metastasis

Abstract Malignant pheochromocytoma of the mandible is an extremely uncommon tumour. This report describes a 59-year-old woman with pheochromocytoma metastatic to the mandible. The patient was referred with a painless mandibular swelling on the right side. She had undergone dual tumour ablation for a pheochromocytoma of the adrenal medulla 7 years and 6 months previously, and for a pheochromocytoma metastatic lesion on the pelvis 2 years and 8 months previously. Radiographic examinations revealed a well-circumscribed radiolucent lesion of the mandibular ramus. A definitive diagnosis of malignant pheochromocytoma was made following a partial mandibulectomy. The patient died of disseminated intravascular coagulation and multiple bone metastases of pheochromocytoma about 10 years after the initial diagnosis of disease.