White paper on guidelines concerning enteric nervous system stem cell therapy for enteric neuropathies

Over the last 20 years, there has been increasing focus on the development of novel stem cell based therapies for the treatment of disorders and diseases affecting the enteric nervous system (ENS) of the gastrointestinal tract (so-called enteric neuropathies). Here, the idea is that ENS progenitor/stem cells could be transplanted into the gut wall to replace the damaged or absent neurons and glia of the ENS. This White Paper sets out experts' views on the commonly used methods and approaches to identify, isolate, purify, expand and optimize ENS stem cells, transplant them into the bowel, and assess transplant success, including restoration of gut function. We also highlight obstacles that must be overcome in order to progress from successful preclinical studies in animal models to ENS stem cell therapies in the clinic.

Abstract P1-05-22: Breast cancer cells that undergo an Epithelial-to-Mesenchymal transition co-opt LPP, a regulator of mesenchymal cell migration and invasion

Transforming Growth Factor β (TGFβ) promotes breast cancer cell metastasis to multiple sites, including the bone and lungs. TGFβ is a strong inducer of Epithelial-to-Mesenchymal transitions (EMT) and breast cancers that exhibit features of an EMT acquire stem cell-like characteristics, are highly aggressive, are resistant to therapy and are refractory to tumor suppressive processes. While TGFβ itself is non-oncogenic, it is a potent modifier of the malignant phenotype in breast cancer and is capable of enhancing the migration, invasion and metastasis of ErbB2 expressing breast cancer cells.

We have identified Lipoma Preferred Partner (LPP) as an indispensable regulator of TGFβ-induced migration and invasion of ErbB2 expressing breast cancer cells. LPP is ubiquitously expressed in smooth muscle cells where it mediates cell adhesion, migration and the formation of lamellipodial extensions. We hypothesize that breast cancer cells capable of undergoing an EMT can utilize novel mediators that are engaged in promoting the migration and invasion of mesenchymal cells. We propose that LPP is one such example, which promotes the migration and invasion of ErbB2 expressing breast cancer cells that have undergone a TGFβ-induced EMT.

We demonstrate that ErbB2 expressing breast cancer cells display significant increases in cell migration and invasion upon TGFβ stimulation, and such responses are dependent on LPP expression. We show that LPP re-localizes to focal adhesion complexes following TGFβ-induced EMT and it is a critical determinant in focal adhesion turnover. Furthermore, we determined that LPP targeting to focal adhesions through its LIM1 domain requires the cooperation of ErbB2 and TGFβ signaling pathways. Finally, we demonstrate that LPP promotes TGFβ-induced migration and invasion of ErbB2 expressing breast cancer cells through recruitment of α-Actinin, an actin cross-linking protein.

Overall, we have identified LPP as a novel mediator that integrates TGFβ and ErbB2 signaling to promote the migration and invasion of breast cancer cells that undergo an EMT. Our data reveal that breast cancer cells, which can transition from an epithelial to mesenchymal phenotype, can engage a regulator of mesenchymal cell migration and invasion.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-05-22.

Cdc25B as a steroid receptor coactivator

The traditional role of the Cdc25 family of dual-specificity phosphatases is to activate cyclin-dependent kinases (CDKs) to enable progression through the cell cycle. This chapter reports that in addition to its cell cycle role, Cdc25B functions as a novel steroid receptor coactivator (SRC). When overexpressed in transgenic mammary glands, Cdc25B can up-regulate the expression of two estrogen receptor (ER)-target genes: cyclin D1 and Lactoferrin. In addition, when coexpressed with ER, Cdc25B can coactivate an ER-dependent reporter in the presence of estradiol. The coactivation of Cdc25B can be extended to the glucocorticoid receptor (GR), progesterone receptor (PR), and androgen receptor (AR). Because of the respective importance of ER and AR in breast and prostate cancer, this chapter focuses on the coactivation of both receptors by Cdc25B. We demonstrate that Cdc25B can interact directly with these nuclear receptors, recruit and enhance the activity of histone acetyltransferases (HATs), and potentiate cell-free transcription independent of its cell cycle regulatory function. Furthermore, because Cdc25B is up-regulated in highgrade and poorly differentiated prostate tumors, which are likely transiting from the hormone-dependent to hormone-independent state, we hypothesize that the coactivation of AR by Cdc25B may induce genes responsible for this progression. Taken together, it is highly conceivable that Cdc25B can promote neoplasia by its two disparate functions of (1) coactivation to induce higher levels of expression of steroid receptor target genes and (2) its role of activating CDKs to deregulate progression of the cell cycle, DNA replication, and mitosis.

Discriminant cognitive factors in responder and non-responder patients with schizophrenia

To identify which improvements in cognitive function are associated with symptom resolution in schizophrenic patients treated with atypical antipsychotics.

DESIGN

a prospective open trial with atypical neuroleptics (risperidone, clozapine, quetiapine).

SETTING

Inpatient and outpatient units, Institute of Psychiatry.

PATIENTS

Thirty-nine patients with schizophrenia according to DSM-IV criteria were included. Clinical and cognitive assessment were done at baseline (T0) and again after six months of treatment (T2). Twenty-five patients completed the trial.

INTERVENTIONS

New-generation antipsychotics during six months. Patients were considered as responders if their PANSS score decreased at least 20% (n = 15) and non-responders if it did not (n = 10).

OUTCOME MEASURES

a computerized cognitive assessment comprised tests of short-term-memory (digit span), explicit long-term memory (word pair learning), divided attention, selective attention and verbal fluency (orthographic and semantic). Clinical assessment included PANSS and ESRS.

RESULTS

A discriminant function analysis was performed to determine which changes in cognitive performance predicted symptomatic response status. Semantic fluency and orthographic fluency were significant predictors. Together they correctly predicted responder status in 88% of cases. Memory was not a significant predictor of symptomatic response.

CONCLUSION

Verbal fluency discriminated the responder from the non-responder group during a pharmacological treatment.