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It recently has been reported that partial-epithelial–mesenchymal transition (p-EMT) program is associated with metastasis in head and neck squamous cell carcinoma (HNSCC). We previously have identified POSTN (which encodes periostin) as an invasion-promoting molecule in HNSCC. Interestingly, POSTN expression is frequently observed in cancer cells with higher p-EMT score by using a previous single-cell transcriptomic data of HNSCC cases. Although it is known that POSTN has 11 splicing variants, the role of them has not been determined in HNSCC. Here, we found that HNSCC cells with EMT features expressed POSTN isoforms, Iso3 (lacking exon 17 and 21) and Iso5 (lacking exon 17), whereas fibroblast expressed Iso3 and Iso4 (lacking exon 17, 18, and 21). The expression of POSTN Iso3 and Iso4 are known to be widely observed in various cell types including stromal cells. Therefore, we focused on the role of novel cancer cell-derived POSTN isoform, Iso5, in HNSCC. Single overexpression of POSTN Iso5 as well as Iso3 promoted invasion. Surprisingly, Iso5 synergistically promoted invasion together with Iso3. Notably, Iso5 as well as Iso3 upregulated p-EMT-related genes. We suggest that a novel cancer-specific POSTN isoform lacking exon 17 (Iso5) can be a useful marker for detecting cancer cells undergoing p-EMT. Moreover, a POSTN Iso5 can be a novel target for diagnosis and therapy in HNSCC.

Objective: Recent studies have revealed that the ability of cancer cells to undergo intermediate state of EMT, partial EMT (p-EMT) poses a higher metastatic risk rather than complete EMT. Here we examined the prognostic value of p-EMT-related genes in head and neck squamous cell carcinoma (HNSCC) by bioinformatics approaches. Materials and Methods: We used RNA-seq data of 519 primary HNSCC cases obtained from TCGA database. We compared the expression of p-EMT-related genes in HNSCC tissues with normal tissues. We evaluated the prognostic value of p-EMT-related genes in HNSCC cases by Log-rank test. We examined the expression of p-EMT-, EMT-, and epithelial differentiation-related genes by qPCR. Results: Among p-EMT-related genes that were highly expressed in HNSCC cases, high expression of SERPINE1, ITGA5, TGFBI, P4HA2, CDH13, and LAMC2 was significantly correlated with poor survival of HNSCC patients. By gene expression pattern, HNSCC cell lines were classified into three groups; epithelial phenotype, EMT-phenotype, and p-EMT phenotype. Conclusions: Our findings suggest that p-EMT program may be involved in poor prognosis of HNSCC. SERPINE1, ITGA5, TGFBI, P4HA2, CDH13, and LAMC2 can be used for a prognostic marker. Moreover, HNSCC cells with p-EMT phenotype can be a useful model for investigating a nature of p-EMT.

During mitosis, the chromosomal passenger complex (CPC) ensures the faithfultransmission of the genome. CPC is composed of the enzymatic component Aurora B andthe three regulatory and targeting components Borealin, INCENP, and Survivin.Although CPC is known to be involved in diverse mitotic events, it is still unclear howCPC function terminates after mitosis. Here we show that Borealin is ubiquitylated bythe anaphase promoting complex/cyclosome (APC/C) and its cofactor Cdh1 andsubsequently degraded in G1 phase. Cdh1 binds to the regions within N-terminus ofBorealin that act as a non-canonical degron. Aurora-B has also been shown previously tobe degraded by the APC/CCdh1 from late mitosis to G1. Indeed, Cdh1 depletion sustains anAurora-B activity with stable levels of Borealin and Aurora-B throughout the cell cycleand causes less efficiency of DNA replication after release from serum starvation.Notably, inhibition of Aurora-B kinase activity improves the efficiency of DNAreplication in Cdh1-depleted cells. We thus propose that APC/CCdh1 terminates the CPCactivity upon mitotic exit, and thereby contributes to proper control of DNA replication.

Objective. Dysregulated chemokine signaling contributes to autoimmune diseases by facilitating aberrant T-cell infiltration into target tissues, but the specific cytokines, receptors, and T-cell populations remain largely unidentified. Role of the potent chemokine CXCL12 and its receptor CXCR4 in T-cell autoimmune response was examined using alymphoplasia (aly)/aly mice, a Sjögren’s syndrome (SS) model. Methods. T-cell phenotypes in the salivary gland of aly/aly mice were evaluated using immunological analysis. In vitro migration assay was used to assess T-cell migratory activity toward several chemokines. Gene expression of chemokine receptors, and transforming growth factor (TGF)β receptors was measured with quantitative reverse transcription-polymerase chain reaction. The CXCR4 antagonist AMD3100 was administered to the aly/aly mice to evaluate its suppressive effect on autoimmune lesions. Results. Effector memory T (TEM) cells derived from aly/aly mice demonstrated higher in vitro migratory activity toward CXCL12 than aly/+ TEM cells. CXCL12 expression was specifically upregulated in the SS target cells of aly/aly mice. TEM cells from RelB−/− mice, but not nuclear factor (NF)-κB1−/− mice, also showed high migratory activity toward CXCL12, implicating a nonclassical NF-κB2/RelB pathway in the regulation of TEM cell migration. TEM cells from aly/aly mice also overexpressed TGFβ receptors I and II. The CXCR4 antagonist AMD3100 suppressed autoimmune lesions in aly/aly mice by reducing TEM cell infiltration. Conclusion. Our results suggest that the NF-κB2/RelB pathway regulates T-cell migration to autoimmune targets through TGFβ/TGFβR-dependent regulation of CXCL12−CXCR4 signaling. This suggests that these signaling pathways are potential therapeutic targets for treating autoimmune diseases.

The maternal immune system during pregnancy is largely changed to maintain immune tolerance against the embryo. Although thymus tissues, which generate T cells, are also dynamically altered during pregnancy, the precise phenotype of thymic T cells and gene alteration in thymus tissues remain to be completely elucidated. In this study, we performed a comprehensive analysis of gene expression and assessed T-cell phenotypic changes in the thymus of mice during pregnancy. Thymus tissues of female C57BL/6 mice during pregnancy were resected to investigate T-cell phenotypes using flow cytometric and immunofluorescence analyses and gene expression using a DNA microarray. Decreased weight of thymus tissues was observed during gestation. Cell numbers of total populations of thymic T cells in pregnant mice were significantly decreased compared with those in non-pregnant mice. DNA microarray and RT-PCR analyses revealed several upregulated genes in the thymus tissues of pregnant mice. Among them, the insulin growth factor-binding protein 5 (IGFBP5) was the most upregulated gene, and its increased protein expression of macrophages was confirmed by immunofluorescence analysis. In summary, a unique change in gene expression was observed in transient atrophy of thymus tissues during pregnancy. The change in gene expression, including that in IGFBP5 of macrophages, may influence thymic differentiation of T cells to maintain an immunological tolerance during pregnancy.

Objective: Clear cell odontogenic carcinoma (CCOC) is a rare malignant odontogenic tumor (MOT) characterized by sheets and lobules of vacuolated and clear cells. To understand the biology of CCOC, we established a new cell line, CCOC-T, with EWSR1-ATF1 fusion gene from a mandible tumor with distant metastasis and characterized this cell line. Materials and methods: To detect the EWSR1-ATF1 fusion gene, we used three CCOC cases, including the present case, by RT-PCR and FISH analysis. We characterized established CCOC-T cells by checking cell growth, invasion and the expression of odontogenic factors and bone-related factors. Moreover, the gene expression profile of CCOC-T cells was examined by microarray analysis. Results: Histologically, the primary tumor was comprised of cords and nests containing clear and squamoid cells separated by fibrous septa. In addition, ameloblastomatous islands with palisaded peripheral cells were observed, indicating probable odontogenic origin. This tumor expressed the fusion gene EWSR1-ATF1, which underlies the etiology of hyalinizing clear cell carcinoma (HCCC) and potentially that of CCOC. We found a breakpoint in the EWSR1-ATF1 fusion to be the same as that reported in HCCC. Established CCOC-T cells grew extremely slowly, but the cells showed highly invasive activity. Moreover, CCOC-T cells expressed bone-related molecules, odontogenic factors, and epithelial mesenchymal transition (EMT)-related molecules. Conclusion: To the best of our knowledge, this is the first report on the establishment of a CCOC cell line. CCOC-T cells serve as a useful in vitro model for understanding the pathogenesis and nature of MOT.

Both autoimmunity and tumor immunity are immune responses against self-tissues or cells. However, the precise similarity or difference between them remains unclear. In this study, to understand a novel mechanism of tumor immunity, we performed transplantation experiments with a murine autoimmune model, C57BL/6J (B6)/lpr mice. A melanoma cell line, B16F10 cells, or granulocyte macrophage colony-stimulating factor- overexpressing B16F10 (B16F10/mGM) cells were transplanted into B6 or B6/lpr mice. Tumor growth by transplanted B16F10/mGM cells was significantly accelerated in B6/lpr mice compared with that in B6 mice. The accumulation of M1 macrophages in the tumor tissues of B6/lpr recipient mice was significantly lower compared with that in the control mice. In vitro co-culture experiment showed that impaired differentiation into M1 macrophages was observed in B6/lpr mice. The number of tumor vessels and vascular endothelial growth factor (VEGF) expression were also significantly enhanced in the tumor tissues of B6/lpr mice compared with those in the B6 mice. Moreover, VEGF expression was correlated with the increased expression of hypoxia-inducible factor-1α in the tumor tissues of B6/lpr mice. These results suggest that dysfunctional tumor immunity and enhanced angiogenesis in autoimmunity influence tumor growth.