Structural insights and predictive modelling of a novel anti-HER2 scFv and Leptulipin: a newly designed immunotoxin protein for HER2 positive cancers.

Targeted therapy is one crucial therapeutic approach frequently employed in cancer treatment. In almost 30% of human breast cancers, a transmembrane tyrosine kinase receptor named the HER2 (human epidermal growth factor receptor 2) is overexpressed, establishing HER-2 as a promising target for cancer treatment. The goal of the current work is to computationally design and analyze a new chimeric protein that could selectively target HER2-positive breast cancer cells based on a single polypeptide chain variable fragment and leptulipin (an anticancer peptide) fusion.

CD133 in Breast Cancer Cells: More than a Stem Cell Marker.

Initially correlated with hematopoietic precursors, the surface expression of CD133 was also found in epithelial and nonepithelial cells from adult tissues in which it has been associated with a number of biological events. CD133 is expressed in solid tumors as well, including breast cancer, in which most of the studies have been focused on its use as a surface marker for the detection of cells with stem-like properties (i.e.

Ectopic expression of PLC-β2 in non-invasive breast tumor cells plays a protective role against malignant progression and is correlated with the deregulation of miR-146a.

Cells in non-invasive breast lesions are widely believed to possess molecular alterations that render them either susceptible or refractory to the acquisition of invasive capability. One such alteration could be the ectopic expression of the β2 isoform of phosphoinositide-dependent phospholipase C (PLC-β2), known to counteract the effects of hypoxia in low-invasive breast tumor-derived cells. Here, we studied the correlation between PLC-β2 levels and the propensity of non-invasive breast tumor cells to acquire malignant features.

Protective role of all-trans retinoic acid (ATRA) against hypoxia-induced malignant potential of non-invasive breast tumor derived cells.

Background: The presence of hypoxic areas is common in all breast lesions but no data clearly correlate low oxygenation with the acquisition of malignant features by non-invasive cells, particularly by cells from ductal carcinoma in situ (DCIS), the most frequently diagnosed tumor in women.

Methods: By using a DCIS-derived cell line, we evaluated the effects of low oxygen availability on malignant features of non-invasive breast tumor cells and the possible role of all-trans retinoic acid (ATRA), a well-known anti-leukemic drug, in counteracting the effects of hypoxia. The involvement of the β2 isoform of PI-PLC (PLC-β2), an ATRA target in myeloid leukemia cells, was also investigated by specific modulation of the protein expression.

Up-modulation of PLC-β2 reduces the number and malignancy of triple-negative breast tumor cells with a CD133/EpCAM phenotype: a promising target for preventing progression of TNBC.

Background: The malignant potential of triple negative breast cancer (TNBC) is also dependent on a sub-population of cells with a stem-like phenotype. Among the cancer stem cell markers, CD133 and EpCAM strongly correlate with breast tumor aggressiveness, suggesting that simultaneous targeting of the two surface antigens may be beneficial in treatment of TNBC. Since in TNBC-derived cells we demonstrated that PLC-β2 induces the conversion of CD133 to CD133 cells, here we explored its possible role in down-modulating the expression of both CD133 and EpCAM and, ultimately, in reducing the number of TNBC cells with a stem-like phenotype.

PLC-β2 is modulated by low oxygen availability in breast tumor cells and plays a phenotype dependent role in their hypoxia-related malignant potential.

Limited oxygen availability plays a critical role in the malignant progression of breast cancer by orchestrating a complex modulation of the gene transcription largely dependent on the tumor phenotype. Invasive breast tumors belonging to different molecular subtypes are characterized by over-expression of PLC-β2, whose amount positively correlates with the malignant evolution of breast neoplasia and supports the invasive potential of breast tumor cells. Here we report that hypoxia modulates the expression of PLC-β2 in breast tumor cells in a phenotype-related manner, since a decrease of the protein was observed in the BT-474 and MCF7 cell lines while an increase was revealed in MDA-MB-231 cells as a consequence of low oxygen availability.