Inactivation Patterns of p16/INK4A in Oral Squamous Cell Carcinomas

The p16/INK4A is one of the major target genes in carcinogenesis and its inactivation has frequently been reported in other types of tumors. The purpose of this study is to evaluate inactivation patterns of p16/INK4A in oral squamous cell carcinoma. Six different oral cancer cell lines, SCC-4, SCC-9, SCC-15, SCC-25, KB, and SNUDH- 379 were examined for inactivation of p16/INK4A genes. In the analysis of p16/INK4A gene inactivation, PCR amplification, direct sequencing, and methylation-specific PCR methods were adopted for evaluation of homozygous deletion, point mutation, and promoter hypermethylation, respectively. Homozygous deletion was detected in SCC-25 and SCC-9. SCC-15 showed hypermethylated promoter region within p16/INK4A gene. It is suggestive in the present study that inactivation patterns of p16/INK4A were mainly homozygous deletion, promoter methylation rather than point mutation in oral squamous cancer cell lines, so treatment modalities of oral squamous cell carcinoma should be focused on these types of inactivation

YH29407 with anti-PD-1 ameliorates anti-tumor effects via increased T cell functionality and antigen presenting machinery in the tumor microenvironment

Among cancer cells, indoleamine 2, 3-dioxygenase1 (IDO1) activity has been implicated in improving the proliferation and growth of cancer cells and suppressing immune cell activity. IDO1 is also responsible for the catabolism of tryptophan to kynurenine. Depletion of tryptophan and an increase in kynurenine exert important immunosuppressive functions by activating regulatory T cells and suppressing CD8+ T and natural killer (NK) cells. In this study, we compared the anti-tumor effects of YH29407, the best-in-class IDO1 inhibitor with improved pharmacodynamics and pharmacokinetics, with first and second-generation IDO1 inhibitors (epacadostat and BMS-986205, respectively). YH29407 treatment alone and anti-PD-1 (aPD-1) combination treatment induced significant tumor suppression compared with competing drugs. In particular, combination treatment showed the best anti-tumor effects, with most tumors reduced and complete responses. Our observations suggest that improved anti-tumor effects were caused by an increase in T cell infiltration and activity after YH29407 treatment. Notably, an immune depletion assay confirmed that YH29407 is closely related to CD8+ T cells. RNA-seq results showed that treatment with YH29407 increased the expression of genes involved in T cell function and antigen presentation in tumors expressing ZAP70, LCK, NFATC2, B2M, and MYD88 genes. Our results suggest that an IDO1 inhibitor, YH29407, has enhanced PK/PD compared to previous IDO1 inhibitors by causing a change in the population of CD8+ T cells including infiltrating T cells into the tumor. Ultimately, YH29407 overcame the limitations of the competing drugs and displayed potential as an immunotherapy strategy in combination with aPD-1

Inhibition of Akt activity induces the mesenchymal-to-epithelial reverting transition with restoring E-cadherin expression in KB and KOSCC-25B oral squamous cell carcinoma cells

<p>Abstract</p> <p>Background</p> <p>The Akt/PKB family of kinases is frequently activated in human cancers, including oral squamous cell carcinoma (OSCC). Akt-induced epithelial-to-mesenchymal transition (EMT) involves downregulation of E-cadherin, which appears to result from upregulation of the transcription repressor Snail. Recently, it was proposed that carcinoma cells, especially in metastatic sites, could acquire the mesenchymal-to-epithelial reverting transition (MErT) in order to adapt the microenvironments and re-expression of E-cadherin be a critical indicator of MErT. However, the precise mechanism and biologic or clinical importance of the MErT in cancers have been little known. This study aimed to investigate whether Akt inhibition would restore the expression of E-cadherin and β-catenin, reduce that of Vimentin, and induce the MErT in OSCC cells with low or negative expression of E-cadherin. We also investigate whether inhibition of Akt activity would affect the E-cadherin repressors and signaling molecules like NF-κB, ERK, and p38.</p> <p>Methods</p> <p>We screened several OSCC cell lines in order to select suitable cell line models for inducing MErT, using immunoblotting and methylation specific-PCR. We examined whether Akt inhibitor phosphatidylinositol ether lipid analogues (PIA) treatment would restore the expression of E-cadherin and β-catenin, reduce that of Vimentin, and induce the MErT in KB and KOSCC-25B cells using RT-PCR, immunoblotting, immunofluorescence analysis, and <it>in vitro </it>migration assay. We also investigated whether inhibition of Akt activity would affect the E-cadherin repressors, including Snail, Twist, and SIP-1/ZEB-2 and signaling molecules like NF-κB, ERK, JNK, and p38 using RT-PCR, immunoblotting, and immunofluorescence analysis.</p> <p>Results</p> <p>Of the 7 OSCC cell lines, KB and KOSCC-25B showed constitutively activated phosphorylated Akt and low or negative expression of E-cadherin. Inhibition of Akt activity by PIA decreased NF-κB signaling, but did not affect phosphorylation of ERK, JNK, and p38 in KB and KOSCC-25B cells. Akt inhibition led to downregulation of Snail and Twist expression. In contrast, inhibition of Akt activity by PIA did not induce any changes in SIP-1/ZEB-2 expression. PIA treatment induced the expression of E-cadherin and β-catenin, reduce that of Vimentin, restored their epithelial morphology of a polygonal shape, and reduced tumor cell migration in KB and KOSCC-25B cells, which was the corresponding feature of MErT.</p> <p>Conclusion</p> <p>All of these findings suggest that Akt inhibition could induce the MErT through decreased NF-κB signaling and downregulation of Snail and Twist in OSCC cells. A strategy involving Akt inhibition might be a useful therapeutic tool in controlling cancer dissemination and metastasis in oral cancer patients.</p

A Study on the Community of Waterbirds and Protective value at Gangjin Bay in Jeollanamdo, Korea

AbstractThis study was conducted in Gangjin Bay of Jeollanam-do over a total of 8 sessions, once each month, between October of 2009 and May of 2010. A total of 9,647 birds of 63 species were observed during the study period. The most dominant species was Aythya ferina (18.5%), followed by, in decreasing order, Anas platyrhynchos (11.5%), Calidris alpine (9.6%) and Cygnus Cygnus (7.7%). Species which appeared in all months (100% occurrence rate) included a total of 5 species of Ardea cinerea, Egretta alba modesta, Egretta garzetta, Anas crecca and Anas poecilorhyncha. Furthermore, the study showed a total of 13 government protected species, 3 class-I endangered species, 8 class-II endangered species and 8 natural monument species. The Gangjin Bay region includes the Nakdong estuary, natural monument number 179, and provides stopping grounds for the Cygnus Cygnus, at the next highest number of birds. Furthermore, the region is characterized by the wintering of Cygnus Cygnus at a bird count higher than that of the Jindo Cygnus Cygnus migration destination, natural monument number 101. Therefore, there is a need for the designation of natural monuments and protected wetlands, as well as continued maintenance, in the Gangjin Bay region

Expression of matrix metalloproteinase-2 and -9 in oral squamous cell carcinomas with regard to the metastatic potential

In order to evaluate the significance of matrix metalloproteinases (MMPs) in predicting the metastatic potential of oral squamous cell carcinomas (SCCs), we compared MMP-2 and -9 expression in 19 metastasizing oral SCCs with that in 25 non-metastasizing cases by immunohistochemistry and gelatin zymography. Immunohistochemistry showed that increased MMP-2 expression was not significantly related to metastasis; increased MMP-9 expression found in oral SCCs was, however, statistically significant (oral SCCs with metastasis, 73.7%; those without metastasis, 36.0%; P<0.05). Gelatin zymography revealed no significant difference in the activated form of MMP-2 between metastasizing and non-metastasizing oral SCCs. In metastasizing SCCs, on the other hand, increases in the activated form of MMP-9 were significant. These results suggest that oral SCCs express MMP-2 and -9, and that MMP-9 may play a more important role than MMP-2 in the metastasis of oral SCCs to adjacent tissue. An analysis of MMP-9 expression may be useful for predicting the metastatic potential of oral SCCs

Ameloblastic carcinoma: an analysis of 6 cases with review of the literature

Objectives. The purpose of this study is to report 6 cases of ameloblastic carcinoma and to analyze all published cases regarding demographic features, clinical behavior, treatment, and prognosis. Study design. We reviewed our 6 cases of ameloblastic carcinoma and 98 cases previously reported in the English literature. Available follow-up data from 59 cases was analyzed. Results. In the analysis of our cases, the average age of 6 patients was 61 years and there was a predilection for the maxilla and male. Five cases arose de novo, whereas 1 case was secondary type of ameloblastic carcinoma. Microscopically, our cases showed malignant cytologic features with some histologic features of ameloblastoma. Malignant cytologic features included nuclear pleomorphism, hyperchromatism, and high mitotic activity (33.3%). Necrosis and vascular invasion were also seen in 4 cases and 1 case, respectively. Immunostaining for cytokeratins 5, 14, and 18 was all positive and labeling index of Ki-67 was 13.91%. Two patients (33.3%) had a metastatic lesion in the regional lymph nodes without distant metastasis. In the analysis of the literature, the mean age was 49.2 years with a wide age range (7-91 years). The rate of occurrence was higher in males, and the most common site of occurrence was the mandible. The male-to-female ratio was 1.97:1 and the mandible-to-maxilla ratio was 1.71:1. Most cases (70%) involved the posterior portion of the jaw. The most common symptom was swelling, followed by pain, ulceration, paresthesia, and trismus. The recurrence rate in patients treated with surgical resection was 28.3%, whereas the rate in cases of conservative therapy was 92.3%. There was a significant correlation between treatment modality and recurrence (P = 0.000). Metastatic lesions were detected in 22% of patients during follow-up, and the lung was the most common area of distant metastasis. The 5- and 10-year survival rates were 72.9% and 56.8%, respectively. There was a significant decrease in the 5-year survival rate in patients with metastasis (21.4%; P = 0.0000). Conclusion. Metastasis from an ameloblastic carcinoma is significantly correlated with poor prognosis. Therefore, diagnosis at an early stage and close periodic screening for metastasis are necessary to improve patient prognosis. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 108: 904-913)

Clinico-Pathologic Conference: Case 5

A 46 year-old Korean man presented with a 2 month-history of a painful swelling on his left maxillary gingiva. Intraoral examination demonstrated a gingival swelling around the left lateral incisor and canine of the maxilla. The swelling was 4 cm in diameter, exhibiting redness and tenderness on palpation. The left central incisor and the lateral incisor were extruded with slight mobility. Panoramic and periapical radiographs revealed a periapical radiolucency extending from tooth #9 to 11, with radiopaque foci (Figs. 1, 2). CT view showed an expansile lesion thinning the cortex of the anterior maxilla (Fig. 3)