Extranodal Extension and Epithelial Cell Adhesion Molecule Over-expression in Oral Squamous Cell Carcinoma.

BACKGROUND/AIM: Concomitant chemoradiotherapy (CCRT) with cisplatin is commonly administered after neck dissection in patients with oral squamous cell carcinoma (OSCC) showing extranodal extension (ENE). This study investigated whether the efficacy of CCRT differed depending on the degree of ENE and whether the expression of epithelial cell adhesion molecule (EpCAM) was associated with prognosis. PATIENTS AND METHODS: Patients with OSCC who underwent neck dissection and had histologically proven neck metastasis (pN+) were investigated retrospectively. ENE was divided into ENE minor (ENEmi; <2 mm) and ENE major (ENEma; ≥2 mm). The expression of EpCAM was also immunohistochemically examined using tissues obtained during neck dissection. RESULTS: One hundred and seventy pN+ cases [ENE(-), n=89; ENEmi, n=23; ENEma, n=58] were included. Multivariate analysis revealed that advanced T stage and ENEma were significantly correlated with poor prognosis. The 5-year disease-specific survival rates in ENE(-), ENEmi, and ENEma groups were 73.7%, 75.5%, and 28.0% respectively. An add-on effect of postoperative CCRT was not seen in the ENEmi group; however, postoperative CCRT improved the survival of patients in the ENEma group. In the ENEma group, the prognosis was significantly worse in EpCAM-positive patients than in EpCAM-negative patients. CONCLUSION: Postoperative CCRT may improve prognosis in ENEma cases. EpCAM expression may be a poor prognostic factor in ENEma cases. On the other hand, postoperative CCRT did not have a significant effect on prognosis in ENEmi cases. Among them, although there was no significant difference in the survival rate, postoperative CCRT could be omitted in ENEmi/EpCAM(-) cases.

Epithelial Cell Adhesion Molecule (EpCAM) Expression Can Be Modulated via NFκB.

The epithelial cell adhesion molecule (EpCAM) is considered an essential proliferation signature in cancer. In the current research study, qPCR induced expression of EpCAM was noted in acute lymphoblastic leukemia (ALL) cases. Costunolide, a sesquiterpene lactone found in crepe ginger and lettuce, is a medicinal herb with anticancer properties. Expression of EpCAM and its downstream target genes (Myc and TERT) wasdownregulated upon treatment with costunolide in Jurkat cells. A significant change in the telomere length of Jurkat cells was not noted at 72 h of costunolide treatment. An in silico study revealed hydrophobic interactions between EpCAM extracellular domain and Myc bHLH with costunolide. Reduced expression of NFκB, a transcription factor of EpCAM, Myc, and TERT in costunolide-treated Jurkat cells, suggested that costunolide inhibits gene expression by targeting NFκB and its downstream targets. Overall, the study proposes that costunolide could be a promising therapeutic biomolecule for leukemia.

Cellular origins of regenerating liver and hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the predominant primary cancer arising from the liver and is one of the major causes of cancer-related mortality worldwide. The cellular origin of HCC has been a topic of great interest due to conflicting findings regarding whether it originates in hepatocytes, biliary cells, or facultative stem cells. These cell types all undergo changes during liver injury, and there is controversy about their contribution to regenerative responses in the liver. Most HCCs emerge in the setting of chronic liver injury from viral hepatitis, fatty liver disease, alcohol, and environmental exposures. The injuries are marked by liver parenchymal changes such as hepatocyte regenerative nodules, biliary duct cellular changes, expansion of myofibroblasts that cause fibrosis and cirrhosis, and inflammatory cell infiltration, all of which may contribute to carcinogenesis. Addressing the cellular origin of HCC is the key to identifying the earliest events that trigger it. Herein, we review data on the cells of origin in regenerating liver and HCC and the implications of these findings for prevention and treatment. We also review the origins of childhood liver cancer and other rare cancers of the liver.

A high-content screen for small-molecule regulators of epithelial cell-adhesion molecule (EpCAM) cleavage yields a robust inhibitor.

Epithelial cell-adhesion molecule (EpCAM) is a transmembrane protein that regulates cell cycle progression and differentiation and is overexpressed in many carcinomas. The EpCAM-induced mitogenic cascade is activated via regulated intramembrane proteolysis (RIP) of EpCAM by ADAM and γ-secretases, generating the signaling-active intracellular domain EpICD. Because of its expression pattern and molecular function, EpCAM is a valuable target in prognostic and therapeutic approaches for various carcinomas. So far, several immunotherapeutic strategies have targeted the extracellular domain of EpCAM. However, targeting the intracellular signaling cascade of EpCAM holds promise for specifically interfering with EpCAM's proliferation-stimulating signaling cascade. Here, using a yellow fluorescence protein-tagged version of the C-terminal fragment of EpCAM, we established a high-content screening (HCS) of a small-molecule compound library (n = 27,280) and characterized validated hits that target EpCAM signaling. In total, 128 potential inhibitors were initially identified, of which one compound with robust inhibitory effects on RIP of EpCAM was analyzed in greater detail. In summary, our study demonstrates that the development of an HCS for small-molecule inhibitors of the EpCAM signaling pathway is feasible. We propose that this approach may also be useful for identifying chemical compounds targeting other disorders involving membrane cleavage-dependent signaling pathways.

[Enhancement of thermal damage to EpCAM-positive tumor cells by novel aptamer-guided magnetic nanoparticles].

Objective: To explore the thermal damage to epithelial cell adhesion molecule(EpCAM)-positive tumor cells by novel aptamer-guided magnetic nanoparticles(AptNPs). Methods: EpCAM aptamer SYL3C was connected to NPs via biotin-streptavidin reaction. The diameter of AptNPs were characterized by Dynamic Light Scattering(DLS). The binding feature of the aptamer to EpCAM-positive tumor cells was evaluated by Prussian blue dyeing. Thermal damage under alternative magnetic field was measured bylactate dehydrogenase (LDH). The apoptosis of EpCAM-positive tumor cells was detected by acridine orange/ethidium bromide (AO/EB) double staining. Results: The average size of AptNPs was 282 nm. Flow cytometry and Prussian blue dyeing showed that AptNPs exhibited strong binding to the EpCAM-positive tumor cells but not to the EpCAM-negative tumor cells. Moreover, when incubated with 1.5×10(8) AptNPs under alternative electromagnetic fieldfor 5 hours, the viability of EpCAM-positive HCT116 cells and A549 cells was 28.9% and 54.4%, respectively, significantly lower than 76.7% of EpCAM-negative HepG2 cells (P<0.05). Conclusions: AptNPs can improve the thermal damage to EpCAM-positive tumor cells, and may have potential utility in the development of tumor targeted therapy.

Molecular markers of putative spermatogonial stem cells in the domestic cat.

Spermatogonial stem cells (SSCs) are an important tool for fertility preservation and species conservation. The ability to expand SSCs by in vitro culture is a crucial premise for their use in assisted reproduction. Because SSCs represent a small proportion of the germ cells in the adult testis, culture success is aided by pre-enrichment through sorting techniques based on cell surface-specific markers. Given the importance of the domestic cat as a model for conservation of endangered wild felids, herein we sought to examine culture conditions as well as molecular markers for cat SSCs. Using a cell culture medium for mouse SSCs supplemented with glial cell-derived neurotrophic factor (GDNF), germ cells from prepuberal cat testes remained viable in culture for up to 43 days. Immunohistochemistry for promyelocytic leukaemia zinc finger (PLZF) protein on foetal, prepuberal and adult testis sections revealed a pattern of expression consistent with the labelling of undifferentiated spermatogonia. Fluorescence-activated cell sorting (FACS) with an antibody against epithelial cell adhesion molecule (EPCAM) was used to sort live cells. Then, the gene expression profile of EPCAM-sorted cells was investigated through RT-qPCR. Notably, EPCAM (+) cells expressed relatively high levels of CKIT (CD117), a surface protein typically expressed in differentiating germ cells but not SSCs. Conversely, EPCAM (-) cells expressed relatively high levels of POU domain class 5 transcription factor 1 (POU1F5 or OCT4), clearly a germ line stem cell marker. These results suggest that cat SSCs would probably be found within the population of EPCAM (-) cells. Future studies should identify additional surface markers that alone or in combination can be used to further enrich SSCs from cat germ cells.

Links between hepatic fibrosis, ductular reaction, and progenitor cell expansion.

Interactions between cells and their extracellular matrix have been shown to be crucial in a wide range of biological processes, including the proliferation and differentiation of stem cells. Ductular reactions containing both hepatic progenitor cells and extracellular matrix are seen in response to acute severe and chronic liver injury. Understanding the molecular mechanisms whereby cell-matrix interactions regulate liver regeneration may allow novel strategies to enhance this process. Both the ductular reaction in humans and hepatic progenitor cells in rodent models are closely associated with collagen and laminin, although there is still debate about cause and effect. Recent studies have shown a requirement for matrix remodeling by matrix metalloproteinases for the proliferation of hepatic progenitor cells and suggested defined roles for specific matrix components. Understanding the interactions between progenitor cells and matrix is critical for the development of novel regenerative and antifibrotic therapies.

All-trans retinoic acid potentiates the chemotherapeutic effect of cisplatin by inducing differentiation of tumor initiating cells in liver cancer.

BACKGROUND & AIMS: Systemic chemotherapy serves as an adjuvant treatment for post-operation patients with hepatocellular carcinoma (HCC), and provides curative option for the patients with unresectable HCC. However, its efficiency is largely limited because of the high incidence of chemo-resistance. Increasing evidence has shown that tumor initiating cells (TICs) not only have the ability to self-renew and drive the initiation and progression of cancer, but also exhibit greater resistance to conventional chemo- and radio-therapies than non-TICs. It was the aim of this study to investigate the effects of ATRA with and without cisplatin on TIC differentiation and apoptosis in human HCC. METHODS: In the present study, we evaluated the TICs of HCC cell differentiation induced by all-trans retinoic acid (ATRA), and developed a novel chemotherapeutic approach to HCC, by characterizing the function of combinatorial treatment with cis-diammineplatinum(II) (cisplatin) and ATRA in vitro and in vivo. RESULTS: ATRA effectively induced differentiation of TICs, which potentiated the cytotoxic effects of cisplatin. The combinatorial treatment of ATRA acid and cisplatin reduced protein kinase B (AKT) (Thr308) phosphorylation, and promoted apoptosis of HCC cells more significantly than treatment with cisplatin alone. In addition, the combined treatment with the two drugs exerted stronger inhibition on either HCC cell migration in vitro or metastasis in vivo, when compared to the treatment with either drug alone. CONCLUSIONS: These results indicated that ATRA could significantly improve the effect of cisplatin, which is at least partially attributed to ATRA-induced differentiation of HCC TICs, and the subsequent decrease in this chemo-resistant subpopulation.