Isolation and Characterization of a Metastatic Hybrid Cell Line Generated by ER Negative and ER Positive Breast Cancer Cells in Mouse Bone Marrow

BACKGROUND: The origin and the contribution of breast tumor heterogeneity to its progression are not clear. We investigated the effect of a growing orthotopic tumor formed by an aggressive estrogen receptor (ER)-negative breast cancer cell line on the metastatic potential of a less aggressive ER-positive breast cancer cell line for the elucidation of how the presence of heterogeneous cancer cells might affect each other's metastatic behavior. METHODS: ER positive ZR-75-1/GFP/puro cells, resistant to puromycin and non-tumorigenic/non-metastatic without exogenous estrogen supplementation, were injected intracardiacally into mice bearing growing orthotopic tumors, formed by ER negative MDA-MB-231/GFP/Neo cells resistant to G418. A variant cell line B6, containing both estrogen-dependent and -independent cells, were isolated from GFP expressing cells in the bone marrow and re-inoculated in nude mice to generate an estrogen-independent cell line B6TC. RESULTS: The presence of ER negative orthotopic tumors resulted in bone metastasis of ZR-75-1 without estrogen supplementation. The newly established B6TC cell line was tumorigenic without estrogen supplementation and resistant to both puromycin and G418 suggesting its origin from the fusion of MDA-MB-231/GFP/Neo and ZR-75-1/GFP/puro in the mouse bone marrow. Compared to parental cells, B6TC cells were more metastatic to lung and bone after intracardiac inoculation. More significantly, B6TC mice also developed brain metastasis, which was not observed in the MDA-MB-231/GFP/Neo cell-inoculated mice. Low expression of ERα and CD24, and high expression of EMT-related markers such as Vimentin, CXCR4, and Integrin-β1 along with high CD44 and ALDH expression indicated stem cell-like characteristics of B6TC. Gene microarray analysis demonstrated a significantly different gene expression profile of B6TC in comparison to those of parental cell lines. CONCLUSIONS: Spontaneous generation of the novel hybrid cell line B6TC, in a metastatic site with stem cell-like properties and propensity to metastasize to brain, suggest that cell fusion can contribute to tumor heterogeneity

A single posterior approach for multilevel modified vertebral column resection in adults with severe rigid congenital kyphoscoliosis: a retrospective study of 13 cases

We report a multilevel modified vertebral column resection (MVCR) through a single posterior approach and clinical outcomes for treatment of severe congenital rigid kyphoscoliosis in adults. Transpedicular eggshell osteotomies and vertebral column resection are two techniques for the surgical treatment of rigid severe spine deformities. The authors developed a new technique combining the two surgical methods as a MVCR, through a single posterior approach, for surgical treatment of severe congenital rigid kyphoscoliosis in adults. Thirteen adult patients with severe rigid congenital kyphoscoliosis deformity were treated by a single posterior approach using a MVCR technique. The surgery processes included a one-stage posterior transpedicular eggshell technique first, and then expanded the eggshell technique to adjacent intervertebra space through abrasive reduction of the vertebral cortices from inside out. All posterior vertebral elements were removed including the cortical vertebral bone around the neural canal. Range of resection of the vertebral column at the apex of the deformity included apical vertebra and both cephalic and/or caudal adjacent wedged vertebrae. Totally, 32 vertebrae had been removed in 13 patients, with 2.42 vertebrae being removed on average in each case. The average fusion extent was 7.69 vertebrae. Mean operation time was 266 min with average blood loss of 2,411.54 ml during operation. Patients were followed up for an average duration of 2.54 years. Deformity correction was 59% in the coronal plane (from 79.7° to 32.4°) postoperatively and 33.7° (57% correction) at 2 years follow-up. In the sagittal plane, correction was from preoperative 85.9° to 27.5° immediately after operation, and 32.0° at 2 years follow-up. Postoperative pain was reduced from preoperative 1.77 to 0.54 at 2 years follow-up in visual analog scale. SRS-24 scale was from 38.2 preoperatively to 76.9 at 2 years follow-up postoperative. Complications were encountered in four patients (30.7%) with transient neurology that spontaneously improved without further treatment within 3 months. MVCR technique through a single posterior approach is an effective procedure for the surgical treatment of severe congenital rigid kyphoscoliosis in adults

Potential Contribution of SIM2 and ETS2 Functional Polymorphisms in Down Syndrome Associated Malignancies

Proper expression and functioning of transcription factors (TFs) are essential for regulation of different traits and thus could be crucial for the development of complex diseases. Subjects with Down syndrome (DS) have a higher incidence of acute lymphoblastic leukemia (ALL) while solid tumors, like breast cancer (BC) and oral cancer (OC), show rare incidences. Triplication of the human chromosome 21 in DS is associated with altered genetic dosage of different TFs. V-ets erythroblastosis virus E26 oncogene homolog 2 (ETS2) and Single Minded 2 (SIM2) are two such TFs that regulate several downstream genes involved in developmental and neurological pathways. Here we studied functional genetic polymorphisms (fSNP) in ETS2 and SIM2 encoding genes in a group of patients and control subjects to better understand association of these variants with DS phenotypes.We employed an in silico approach to identify potential target pathways of ETS2 and SIM2. fSNPs in genes encoding for these two TFs were identified using available databases. Selected sites were genotyped in individuals with DS, their parents, ALL, BC, OC as well as ethnically matched control individuals. We further analyzed these data by population-based statistical methods.Allelic/genotypic association analysis showed significant (P < 0.03) differences of rs2070530, rs1051476, rs11254, rs711 for DS subjects compared to control. rs711 also exhibited significantly different genotypic distribution pattern in parents of DS probands (P < 0.02) and BC patients (P < 0.02). Interaction analysis revealed independent main effect of rs711 in all the groups, while rs11254 exhibited independent main effect in DS subjects only. High entropy values were noticed for rs461155 in the solid tumor groups. Significant interactive effects of rs2070531 with rs1051475, rs1051476, rs11254 were observed in all the groups except DS. We infer from the present investigation that the difference in frequencies of fSNPs and their independent as well as interactive effects may be the cause for altered expression of SIM2 and ETS2 in DS and malignant groups, which affects different downstream biological pathways. Thus, altered expression of SIM2 and ETS2 could be one of the reasons for variable occurrence of different malignant conditions in DS