Detection of mutations in the cDNA of the proliferation marker Ki-67 protein in four tumor cell lines

Mutational analysis of extranodal marginal zone lymphoma using next generation sequencing

Extranodal marginal zone lymphoma is a type of low-grade B-cell lymphoma that can be classified as a mucosal-associated lymphoid tissue (MALT) lymphoma. Recently, second-generation or next-generation sequencing (NGS), which allows simultaneous sequencing of hundreds to billions of DNA strands, has been a focus of attention and is rapidly being adopted in various fields. In the present study, paraffin-embedded tissue samples of gastric MALT lymphoma (n=1) and small intestine MALT lymphoma (n=4) were selected, and DNA was extracted from the tissue samples. After performing quality control, NGS was performed using HemaSCAN™, a custom panel of 426 genes, including essential blood cancer genes. NGS revealed single nucleotide variations (SNVs), short insertions and deletions (InDels) and copy number variations (CNVs). These genomic variants were reported as annotated, known or novel variants. An annotated variant, an erb-b2 receptor tyrosine kinase 2 gene amplification, was observed in one patient. Known and novel variants, including SNVs of SET binding protein 6 (SETBP6), Runt-related transcription factor 1 and Kelch-like ECH-associated protein 1 genes, InDel of the marker of proliferation Ki-67 gene, and CNVs of the zinc finger protein 703 and NOTCH1 genes, were observed in ≥2 patients. Additionally, InDels with frameshift mutations were identified in the B-cell lymphoma/leukemia 10, DEAD-box helicase 3 X-linked, forkhead box O3 and mucin 2, oligomeric mucus/gel-forming genes in one patient. Since few NGS studies have been performed on MALT lymphoma, the current results were unable to determine if the different mutations that were identified are ‘actionable’ (that is, potentially responsive to a targeted therapy) Further studies are required to determine the associations between genetic mutations and the development of MALT lymphoma.

BGX-Ki-67 index as a supplementary marker to MIB-1 index, enabling more precise distinction between luminal A and B subtypes of breast carcinoma and eliminating the problem of membranous/cytoplasmic MIB-1 staining

OBJECTIVES

We compared clinical utility of MIB-1 and BGX-Ki-67 clones of anti-Ki-67 antibody in a group of 156 patients with invasive ductal breast cancer.

METHODS

MIB-1 labeling index (MIB-1LI) and BGX labeling index (BGXLI) were evaluated immunohistochemically both in primary tumors (T) and synchronous lymph node metastasis (LNM).

RESULTS

In addition to nuclear MIB-1 staining, in 23 of 145 and 19 of 144 T and LNM, respectively, membranous/cytoplasmic labeling was found. In these cases, BGX-Ki-67 showed exclusively nuclear labeling and presented significantly higher labeling index. High BGXLI(T) was a significant independent negative prognostic factor for disease-free survival. Moreover, based on BGXLI(T)/BGXLI(LNM), patients with high MIB-1LI(T) were stratified into low- and high-risk carriers.

CONCLUSIONS

In carcinomas with membranous/cytoplasmic MIB-1 staining, additional assessment of BGXLI is recommended. It may help in defining breast cancer subtype and in selection of individuals at risk who, despite appropriate therapy, would benefit from more frequent controls aimed at earlier implementation of second-line treatment.

In vitro and in vivo biocompatibility evaluation of a novobiocin stimulus-responsive poly(ethylene glycol)-based hydrogel designed for soft tissue regeneration

In vitro and in vivo biocompatibility evaluation of medical devices designed for soft tissue healing and regeneration is mandatory for new biomaterials targeted toward human application. To this end, a novel stimulus-responsive eight-arm poly(ethylene glycol) (PEG)-based hydrogel for soft tissue regeneration was subjected to preclinical safety evaluation. While in vitro safety testing included determination of half-maximal inhibitory concentrations by cell index impedance measurements, an in vivo pilot rat study focused on detectable signs of oral mucosal inflammation. In a hydrogel with a total volume of 40 µL, the following concentrations of the constituents were released upon hydrogel dissolution in 1 mL body fluid: PEG, 19 µM; gyrase B, 152 µM; and coumermycin, 76 µM, while the dissolving agent novobiocin was effective in a range from 50 to 100 µM. Concerning the components’ biological effects, half-maximal inhibitory concentrations of 806 and 95 µM for human oral mucosal gingival fibroblasts and gingival keratinocytes were calculated for novobiocin, proving gingival keratinocytes more susceptible to substance effects. Furthermore, with respect to coumermycin concentrations, half-maximal inhibitory concentrations of 10 and 3 µM for gingival fibroblasts and gingival keratinocytes, respectively, were obtained, and thereby revealed coumermycin to be toxic in vitro. In vivo, submucosal hard palatal implantation of standard hydrogels showed no evidence of inflammation at any time point under study, which was supported by immunohistochemistry analysis. In order to realize the potential of such a promising stimulus-responsive hydrogel biomaterial concept for soft tissue wound healing and/or regenerative applications, the crosslinker coumermycin and its competitor novobiocin should be replaced by more innocuous alternative protein–ligand pairs.

Expression and prognostic value of the Ki-67 in Wilms' tumor: experience with 48 cases

PURPOSE

Ki-67, tumor proliferation marker, is an important prognostic factor in a variety of cancers. In the present study, we investigated the expression and the prognostic value of Ki-67 in nephroblastoma.

METHODS

Ki-67 expressions were investigated by immunohistochemistry on paraffin-embedded material in 48 children operated on because of nephroblastoma. Patients were treated according to SIOP protocol. The mean follow-up period was 5.4 years. A proliferation index was obtained by immunohistochemistry using anti-Ki-67 anti-body.

RESULTS

The mean Ki-67 proliferation index in the blastemal type was 12.3%, and in the epithelial type, 21.4%. In the anaplastic type, Ki-67 proliferation index was: in the blastemal component 20%, in the stromal 21%, and in the epithelial 31%. In the mixed tumor type, Ki-67 proliferation index was assessed as: in the blastemal component 10%, in the epithelial 33% and in the stromal 31.5%. Proliferation index for the epithelium was significantly higher than those found for the blastema (P = 0.001). A correlation between Ki-67 and tumor stage found proliferation index significantly higher in stages I and II (P = 0.002).

CONCLUSION

The results support the conclusion that Ki-67 is a relevant marker for assessing the proliferative activity and tumor cell dynamics of nephroblastoma, but it may not be a good clinical prognostic marker.

[Ki-67 -- new faces of an old player]

The Ki-67 protein was isolated twenty-five years ago and has become the first histological marker of proliferating cells until now. This molecule with a unique structure possesses such fundamental biological functions that are essential for normal cell proliferation. Since the Ki-67 protein is present in every dividing cell (G1, S, G2/M phase) but is absent from the resting cells (G0 phase) it is very much suitable for identifying the proliferating fraction of cells. Thus, it provides essential information concerning the malignancy of a tumor and about the prediction of response to a certain therapy. Based on its important role in cell proliferation, the Ki-67 protein might also play a role in tumor genesis. In their present work the authors discuss the history and the properties of Ki-67, its role in cell cycle regulation and its prognostic importance in different malignant disorders.

p53 Mutations in carcinoma of the esophagus and gastroesophageal junction

BACKGROUND

Recent studies suggested p53 mutations as a prognostic factor. Tumors of the esophagus and gastroesophageal (GE) junction show raising incidence with a general poor prognosis.

METHODS

p53 Mutational spectra in 103 patients (68 squamous cell carcinoma/SCC and 35 adenocarcinoma/AC) were compared to clinical and pathologic data.

RESULTS AND CONCLUSIONS

p53 Mutations were found in 26 of 68 SSC (38.2%) and in 12 of 35 AC (34.5%). We only found G > T transversions in smokers with SCC. The survival of patients was not affected by p53 mutational status. In our study, the frequency and mutational spectrum of mutant p53 is similar in both histological types without prognostic relevance.