Human placenta and trophoblasts simultaneously express three isoforms of atypical protein kinase-c.

Atypical protein kinase-c (aPKC) isoforms are important regulators of polarity and stem cell differentiation. There are three isoforms of aPKC: aPKC-ι, aPKC-ζ, and PKM-ζ. Recently, aPKC-ι was shown to regulate human trophoblast stem cell (TSC) differentiation. Compensation by remaining isoforms when a single aPKC isoform is lost can occur, but the expression pattern of aPKC-ζ in placenta is unknown. Here we show that aPKC-ι, aPKC-ζ and a new isoform, aPKC-ζ III, are expressed in trophoblasts. Therefore, studies examining the role of aPKC isoforms that control for potential compensation between aPKC isoforms are necessary to understand aPKC-mediated regulation of TSC differentiation.

Essentials in Minimally Invasive Gynecology Manual Skills Pilot Validation Trial.

STUDY OBJECTIVE: To evaluate the Essentials in Minimally Invasive Gynecology (EMIG)- Fundamentals of Laparoscopic Surgery Laparoscopic Simulation System and the EMIG Hysteroscopy Simulation System for face validity and functionality in a pilot testing environment. DESIGN: A prospective controlled pilot study. SETTING: Three teaching institutions in the US Southwest. SUBJECTS: Twenty-seven residents and gynecologists, with 22 fitting who fit 1 of 4 categories of exposure to hysteroscopic and laparoscopic surgery and surgical simulation. Eleven were postgraduate year 1 and 5 postgraduate year 3, 1 was American Board of Obstetrics & Gynecology certified, and 5 were either fellows in-training or had completed a fellowship in minimally invasive gynecologic surgery. INTERVENTIONS: After completing a screening survey, each subject was exposed to a structured orientation to the 2 simulation systems and then tested with proctor supervision on the 5 laparoscopic and 2 hysteroscopic exercises. A short 5-point Likert questionnaire designed to determine face validation and question clarity was administered to each subject at sites 2 and 3. MEASUREMENTS AND MAIN RESULTS: Face validity was high for each of the 7 exercises (means ranged from 4.8 to 4.9 of 5), and subjects considered instructions to be clear (means from 4.7 to 4.9). The recorded exercise times generally reduced with increasing levels of training, although the sample sizes were not designed to determine significance given the pilot design. Similarly, exercise errors were generally less frequent with increasing experience. The systems, including the devices and recording mechanisms, performed well, and proctor evaluation and training were satisfactory. CONCLUSION: The EMIG laparoscopic and hysteroscopic simulations systems were considered to have good face validity and appear to be suitable for a construct validation trial to confirm their utility in distinguishing among trainees and practitioners with a wide spectrum of endoscopic surgical experience. The recording and specimen storage mechanisms will allow for multiple proctors to rate a candidate's performance, thereby enhancing evaluation consistency and quality.

Natural killer cells preferentially target cancer stem cells; role of monocytes in protection against NK cell mediated lysis of cancer stem cells.

Mounting effective anti-tumor immune responses by cytotoxic effectors is important for the clearance of tumors. However, accumulated evidence suggests that the cytotoxic function of immune effectors is largely suppressed in the tumor microenvironment by a number of distinct effectors and their secreted factors. The aims of this review are to provide a rationale and potential mechanism for immunosuppression in cancer, and to demonstrate the significance of such immunosuppression in cellular differentiation and tissue regeneration in pathological conditions, and progression of cancer. We have recently shown that increased NK cell function was seen when they were cultured with primary oral squamous carcinoma stem cells (OSCSCs) as compared to their more differentiated oral squamous carcinoma cells (OSCCs). In addition, human embryonic stem cells (hESCs), Mesenchymal Stem Cells (hMSCs), dental pulp stem cells (hDPSCs) and induced pluripotent stem cells (hiPSCs) were significantly more susceptible to NK cell mediated cytotoxicity than their differentiated counterparts or parental cells from which they were derived. We have also reported that inhibition of differentiation or reversion of cells to a less-differentiated phenotype by blocking NFκB or targeted knock down of COX2 augmented NK cell function significantly. Total population of monocytes and those depleted of CD16(+) subsets were able to substantially prevent NK cell mediated lysis of OSCSCs, MSCs and DPSCs. Taken together, our results suggest that stem cells are significant targets of the NK cell cytotoxicity. The concept of split anergy in NK cells and its contribution to tissue repair and regeneration and in tumor resistance and progression will be discussed in this review. Therefore, patients with cancer may benefit from repeated allogeneic NK cell transplantation at the site of the tumor for specific elimination of cancer stem cells.