Transgene Excision Has No Impact on In Vivo Integration of Human iPS Derived Neural Precursors

The derivation of induced human pluripotent stem cells (hiPS) has generated significant enthusiasm particularly for the prospects of cell-based therapy. But there are concerns about the suitability of iPS cells for in vivo applications due in part to the introduction of potentially oncogenic transcription factors via viral vectors. Recently developed lentiviral vectors allow the excision of viral reprogramming factors and the development of transgene-free iPS lines. However it is unclear if reprogramming strategy has an impact on the differentiation potential and the in vivo behavior of hiPS progeny. Here we subject viral factor-free, c-myc-free and conventionally reprogrammed four-factor human iPS lines to a further challenge, by analyzing their differentiation potential along the 3 neural lineages and over extended periods of time in vitro, as well as by interrogating their ability to respond to local environmental cues by grafting into the striatum. We demonstrate similar and efficient differentiation into neurons, astrocytes and oligodendrocytes among all hiPS and human ES line controls. Upon intracranial grafting in the normal rat (Sprague Dawley), precursors derived from all hiPS lines exhibited good survival and response to environmental cues by integrating into the subventricular zone, acquiring phenotypes typical of type A, B or C cells and migrating along the rostral migratory stream into the olfactory bulb. There was no teratoma or other tumor formation 12 weeks after grafting in any of the 26 animals used in the study. Thus neither factor excision nor persistence of c-myc impact the behavior of hiPS lines in vivo.United States. National Institutes of HealthNew York State Stem Cell ScienceNational Institute of Neurological Disorders and Stroke (U.S.)Starr Foundation (Tri-Institutional Starr Stem Cell Scholars Fellowship

A large scale expression study associates uc.283-plus lncRNA with pluripotent stem cells and human glioma

BACKGROUND: There are 481 ultra-conserved regions (UCRs) longer than 200 bases in the genomes of human, mouse and rat. These DNA sequences are absolutely conserved and show 100% identity with no insertions or deletions. About half of these UCRs are reported as transcribed and many correspond to long non-coding RNAs (lncRNAs). METHODS: We used custom microarrays with 962 probes representing sense and antisense sequences for the 481 UCRs to examine their expression across 374 normal samples from 46 different tissues and 510 samples representing 10 different types of cancer. The expression in embryonic stem cells of selected UCRs was validated by real time PCR. RESULTS: We identified tissue selective UCRs and studied UCRs in embryonic and induced pluripotent stem cells. Among the normal tissues, the uc.283 lncRNA was highly specific for pluripotent stem cells. Intriguingly, the uc.283-plus lncRNA was highly expressed in some solid cancers, particularly in one of the most untreatable types, glioma. CONCLUSION: Our results suggest that uc.283-plus lncRNA might have a role in pluripotency of stem cells and in the biology of glioma

Inositol Phospholipid Signaling and the Biology of Natural Killer Cells

A family of phosphoinositide-3 kinase (PI3K) isoenzymes catalyzes the production of second messengers that recruit critical regulators of cell growth, survival, proliferation and motility. Conversely, 3′- (phosphatase and tensin homolog) and 5′-inositol polyphosphatases (SH2-containing inositol phosphatases 1/2, SHIP1/2) are recruited to sites of PI3K signaling at the plasma membrane to oppose or, in some cases, to modify and enhance PI3K signaling. A substantial and growing body of literature demonstrates that these enzymes which mediate interchange of phosphates on inositol phospholipid species at the plasma membrane have prominent roles in natural killer cell biology, including development, effector functions and trafficking. Here, we review the salient points of these recent papers with a special emphasis on the role of p110δ and SHIP1 in natural killer cells

Pluripotent stem cell miRNAs and metastasis in invasive breast cancer

Background The purpose of this study is to determine whether microRNA for pluripotent stem cells are also expressed in breast cancer and are associated with metastasis and outcome. Methods We studied global microRNA profiles during differentiation of human embryonic stem cells (n =26) and in breast cancer patients (n = 33) and human cell lines (n = 35). Using in situ hybridization, we then investigated MIR302 expression in 318 untreated breast cancer patients (test cohort, n = 22 and validation cohort, n = 296). In parallel, using next-generation sequencing data from breast cancer patients (n = 684), we assessed microRNA association with stem cell markers. All statistical tests were two-sided. Results In healthy tissues, the MIR302 (high)/MIR203 (low) asymmetry was exclusive for pluripotent stem cells. MIR302 was expressed in a small population of cancer cells within invasive ductal carcinoma, but not in normal breast (P < .001). Furthermore, MIR302 was expressed in the tumor cells together with stem cell markers, such as CD44 and BMI1. Conversely, MIR203 expression in 684 breast tumors negatively correlated with CD44 (Spearman correlation, Rho = -0.08, P = .04) and BMI1 (Rho = -0.11, P = .004), but positively correlated with differentiation marker CD24 (Rho = 0.15, P < .001). Primary tumors with lymph node metastasis had cancer cells showing scattered expression of MIR302 and widespread repression of MIR203. Finally, overall survival was statistically significantly shorter in patients with MIR302-positive cancer cells (P = .03). Conclusions In healthy tissues the MIR302(high)/MIR203(low) asymmetry was characteristic of embryonic and induced pluripotency. In invasive ductal carcinoma, the MIR302/MIR203 asymmetry was associated with stem cell markers, metastasis, and shorter survival

Pluripotent stem cell miRNAs and metastasis in invasive breast cancer.

Background The purpose of this study is to determine whether microRNA for pluripotent stem cells are also expressed in breast cancer and are associated with metastasis and outcome. Methods We studied global microRNA profiles during differentiation of human embryonic stem cells (n =26) and in breast cancer patients (n = 33) and human cell lines (n = 35). Using in situ hybridization, we then investigated MIR302 expression in 318 untreated breast cancer patients (test cohort, n = 22 and validation cohort, n = 296). In parallel, using next-generation sequencing data from breast cancer patients (n = 684), we assessed microRNA association with stem cell markers. All statistical tests were two-sided. Results In healthy tissues, the MIR302 (high)/MIR203 (low) asymmetry was exclusive for pluripotent stem cells. MIR302 was expressed in a small population of cancer cells within invasive ductal carcinoma, but not in normal breast (P <. 001). Furthermore, MIR302 was expressed in the tumor cells together with stem cell markers, such as CD44 and BMI1. Conversely, MIR203 expression in 684 breast tumors negatively correlated with CD44 (Spearman correlation, Rho = -0.08, P =. 04) and BMI1 (Rho = -0.11, P =. 004), but positively correlated with differentiation marker CD24 (Rho = 0.15, P <. 001). Primary tumors with lymph node metastasis had cancer cells showing scattered expression of MIR302 and widespread repression of MIR203. Finally, overall survival was statistically significantly shorter in patients with MIR302-positive cancer cells (P =. 03). Conclusions In healthy tissues the MIR302(high)/MIR203(low) asymmetry was characteristic of embryonic and induced pluripotency. In invasive ductal carcinoma, the MIR302/MIR203 asymmetry was associated with stem cell markers, metastasis, and shorter survival

Reprogramming of miRNA networks in cancer and leukemia

International audienc