The Induction of Parathyroid Cell Differentiation from Human Induced Pluripotent Stem Cells Promoted Via TGF-α/EGFR Signaling.

The parathyroid gland plays an essential role in mineral and bone metabolism. Cultivation of physiological human parathyroid cells has yet to be established and the method by which parathyroid cells differentiate from pluripotent stem cells remains uncertain. Therefore, it has been hard to clarify the mechanisms underlying the onset of parathyroid disorders, such as hyperparathyroidism. In this study, we developed a new method of parathyroid cell differentiation from human induced pluripotent stem (iPS) cells. Parathyroid cell differentiation occurred in accordance with embryologic development. Differentiated cells, which expressed the parathyroid hormone, adopted unique cell aggregation similar to the parathyroid gland. In addition, these differentiated cells were identified as calcium-sensing receptor (CaSR)/epithelial cell adhesion molecule (EpCAM) double-positive cells. Interestingly, stimulation with transforming growth factor-α (TGF-α), which is considered a causative molecule of parathyroid hyperplasia, increased the CaSR/EpCAM double-positive cells, but this effect was suppressed by erlotinib, which is an epidermal growth factor receptor (EGFR) inhibitor. These results suggest that TGF-α/EGFR signaling promotes parathyroid cell differentiation from iPS cells in a similar manner to parathyroid hyperplasia.

Lack of EGFR catalytic activity in hepatocytes improves liver regeneration following DDC-induced cholestatic injury by promoting a pro-restorative inflammatory response.

Despite the well-known hepatoprotective role of the epidermal growth factor receptor (EGFR) pathway upon acute damage, its specific actions during chronic liver disease, particularly cholestatic injury, remain ambiguous and unresolved. Here, we analyzed the consequences of inactivating EGFR signaling in the liver on the regenerative response following cholestatic injury. For that, transgenic mice overexpressing a dominant negative mutant human EGFR lacking tyrosine kinase activity (ΔEGFR) in albumin-positive cells were submitted to liver damage induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC), an experimental model resembling human primary sclerosing cholangitis. Our results show an early activation of EGFR after 1-2 days of a DDC-supplemented diet, followed by a signaling switch-off. Furthermore, ΔEGFR mice showed less liver damage and a more efficient regeneration following DDC injury. Analysis of the mechanisms driving this effect revealed an enhanced activation of mitogenic/survival signals, AKT and ERK1/2-MAPKs, and changes in cell turnover consistent with a quicker resolution of damage in response to DDC. These changes were concomitant with profound differences in the profile of intrahepatic immune cells, consisting of a shift in the M1/M2 balance towards M2 polarity, and the Cd4/Cd8 ratio in favor of Cd4 lymphocytes, overall supporting an immune cell switch into a pro-restorative phenotype. Interestingly, ΔEGFR livers also displayed an amplified ductular reaction, with increased expression of EPCAM and an increased number of CK19-positive ductular structures in portal areas, demonstrating an overexpansion of ductular progenitor cells. In summary, our work supports the notion that hepatocyte-specific EGFR activity acts as a key player in the crosstalk between parenchymal and non-parenchymal hepatic cells, promoting the pro-inflammatory response activated during cholestatic injury and therefore contributing to the pathogenesis of cholestatic liver disease. © 2022 The Pathological Society of Great Britain and Ireland.

Deglycosylated EpCAM regulates proliferation by enhancing autophagy of breast cancer cells via PI3K/Akt/mTOR pathway.

Autophagy is an important regulator of cellular homeostasis and its dysregulation often results in cancer. Aberrant glycosylation induced by oncogenic transformation contributes to tumor invasion and metastasis. In a previous study, we have demonstrated that EpCAM, a glycosylation protein, is associated with cell growth and metastasis in breast cancer. But the effect of EpCAM glycosylation on autophagy is not clear. the precise mechanism of regulation remains largely unknown. In this study, breast cancer cells were transfected with N-glycosylation mutation EpCAM plasmid to express deglycosylated EpCAM. The result showed that deglycosylated EpCAM promoted autophagy in breast cancer cells. We further confirmed this conclusion with the activator (Rapamycin, RAP) and inhibitor (Wortmannin) of autophagy. We also found that deglycosylated EpCAM promoted apoptosis and inhibited proliferation through activating autophagy by suppressing Akt/mTOR signaling pathway in breast cancer cells. These findings represent a novel mechanism by which deglycosylated EpCAM inhibits proliferation by enhancing autophagy of breast cancer cells via PI3K/Akt/mTOR pathway. In conclusion, the combination of autophagy modulation and EpCAM targeted therapy is a promising therapeutic strategy in the treatment of breast cancer.

Construction of long-circulation EpCAM targeted drug delivery system and its application in the diagnosis and treatment of breast cancer.

Docetaxel (DOX) is usually one of drugs used for breast cancer treatment. The key of targeted drug delivery therapy is to deliver effective drugs directly and safely to the tumor focus via an efficient targeting drug carrier with immunogenicity. In this study, Long-circulating targeted drug carrying microspheres (DOX-PEG-EpCAM-MNs) entrapping DOX were constructed. In addition, both cytotoxicity and magnetic resonance imaging (MRI) analyses were performed to establish a mouse model and further complete corresponding performance analysis.The results showed that the average particle size of DOX-PEG-EpCAM-MNs was 139.3 ± 1.6 nm. Morphological analysis proves that they are spherical and uniformly dispersed. The Corresponding entrapment rate and drug carrying capacity are 82.43% and 7.16% respectively. Additionally, MRI shows that they have the capability to track tumor cells within 5 days. This study established a safe and efficient breast cancer cells targeted long-circulating drug delivery system.

Androgen Receptor Enhances the Efficacy of Sorafenib Against Hepatocellular Carcinoma Through Enriched EpCAM Stemness.

BACKGROUND/AIM: The role of androgen receptor (AR) in hepatocellular carcinoma (HCC) development is controversial. Therefore, the translational value of targeting AR in HCC is unknown. Sorafenib, a multiple kinase inhibitor, is the standard therapy for patients with unresectable HCC. This study investigated sorafenib effect on AR in experimental models of HCC. MATERIAL AND METHODS: AR cDNA was introduced into HCC cells and in vitro cell growth and in vivo tumor growth were measured. Sphere cells, as well as epithelial cell adhesion molecule-positive (EpCAM+) and CD133+ cells were isolated from HCC cells with/without AR expression to observe in vitro/in vivo effects. Liver specific AR knockout in mouse models of spontaneous HCC (carcinogen-induced and hepatitis B virus-related HCC) was also implemented to examine gene expression. HCC cells/tumors were treated with sorafenib in order to determine effects on tumor growth and related gene expression. RESULT: AR cDNA increased transactivation function, increased colony/sphere-forming activities, and enhanced tumorigenicity in HCC cells compared to their parental cells. Expression of the stemness marker EpCAM was also dramatically increased. In carcinogen-and HBV-induced HCC models, EpCAM+ cells were significantly reduced in AR-knockout mice compared to wild-type HCCs. In addition, AR reduced sorafenib-related signals, e.g. extracellular-regulated kinase, AKT serine/threonine kinase 1, and p38 mitogen-activated protein kinase, compared to that in parental cells. Regarding sorafenib cytotoxicity, AR-expressing cells were vulnerable to treatment. Moreover, the half maximal-inhibitory concentration (IC50) was drastically lowered in AR+/EpCAM+ compared to AR-/EpCAM- sphere cells. Strikingly, the IC50 in AR+/CD133+ vs. AR-/CD133+ cells were similar. Moreover, sorafenib robustly suppressed tumor growth in implanted AR+/EpCAM+ cells but not AR-/EpCAM- ones. Finally, bioinformatics analyses revealed EpCAM to be a prognostic biomarker in Asian and non-alcohol-consuming patients with HCC, suggesting suitability of a sorafenib regimen for such patients. CONCLUSION: AR+/EpCAM+ may be a marker of responsiveness to sorafenib for patients with HCC. Prospective surveys associating AR/EpCAM expression with therapy outcomes are essential.

Human colorectal cancer antigen GA733-2-Fc fused to endoplasmic reticulum retention motif KDEL enhances its immunotherapeutic effects.

OBJECTIVE: The aim of this is to compare the immunotherapeutic effects of human colorectal cancer antigen GA733-2 fused to the Fc fragment of antibody (GA733-2-Fc) and to Fc and endoplasmic reticulum (ER) retention motif KDEL (GA733-2-Fc-KDEL). MATERIALS AND METHODS: Recombinant GA733-2-Fc and GA733-2-Fc-KDEL were produced from infiltrated Nicotiana benthamiana leaves and purified by affinity chromatography. Glycan structures were determined by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. The allergic and immunogenic responses of recombinant GA733-2-Fc and GA733-2-Fc-KDEL were estimated in an intraperitoneally immunized mouse. The tumor regression effect of recombinant GA733-2-Fc and GA733-2-Fc-KDEL was examined using a colorectal carcinoma CT-26 animal model. RESULTS: Recombinant GA733-2-Fc contained plant-specific glycan structures including ß(1,2)-xylose and α(1,3)-fucose whereas recombinant GA733-2-Fc-KDEL contained oligomannose type glycan structures. Mice immunized intraperitoneally with recombinant GA733-2-Fc and GA733-2-Fc-KDEL elicited strong GA733-2-Fc-specific immunoglobulin G (IgG) and IgA serum antibody responses. Recombinant GA733-2-Fc-KDEL reduced the production of GA733-2-Fc-specific IgE. Recombinant GA733-2-Fc-KDEL increased the production of interferon-γ. Intraperitoneal preimmunization with recombinant GA733-2-Fc and GA733-2-Fc-KDEL regressed tumor growth in a colorectal carcinoma CT-26 animal model. The tumor regression effect induced by recombinant GA733-2-Fc-KDEL was greater than that induced by recombinant GA733-2-Fc. The human and mouse colorectal carcinoma cell binding activities of recombinant GA733-2-Fc-KDEL-immunized sera were higher than those of recombinant GA733-2-Fc. CONCLUSIONS: Our results suggest that GA733-2-Fc conjugated to ER-retention motif KDEL is a more efficient antigen to prevent tumor growth induced by colorectal carcinoma and minimize an allergic response.