gonzo (goz) is a zebrafish mutant with defects in cartilage formation. The goz phenotype comprises cartilage matrix defects and irregular chondrocyte morphology. Expression of endoderm, mesoderm, and cartilage marker genes is, however, normal, indicating a defect in chondrocyte morphogenesis. The mutated gene responsible for the goz phenotype, identified by positional cloning and confirmed by phosphomorpholino knockdown, encodes zebrafish site-1 protease (s1p). S1P has been shown to process and activate sterol regulatory element-binding proteins (SREBPs), which regulate expression of key enzymes of lipid biosynthesis or transport. This finding is consistent with the abnormal distribution of lipids in goz embryos. Knockdown of site-2 protease, which is also involved in activation of SREBPs, results in similar lipid and cartilage phenotypes as S1P knockdown. However, knockdown of SREBP cleavage-activating protein, which forms a complex with SREBP and is essential for S1P cleavage, results only in lipid phenotypes, whereas cartilage appears normal. This indicates that the cartilage phenoptypes of goz are caused independently of the lipid defects.T he vertebrate skeleton is comprised of cartilage and bone and is derived from multiple embryologic origins, including neural crest, dorsal paraxial mesoderm, cephalic mesoderm, and lateral mesoderm (for review, see ref. 1). Skeletal development in the vertebrate head is regulated by sonic hedgehog (Shh) (2-5), which is expressed in the rostral axial mesendoderm and the prechordal plate (6). The coexpression of shh and bone morphogenetic proteins (bmps) observed in many developing vertebrate organs suggests a closely regulated relationship between Shh and BMPs (7). It has been shown that BMP-4 induces sox9 and collagen II (Col II) expression and leads to chondrogenesis in mandibular organ culture systems of chick and mouse (8).Mature cartilage consists of chondrocytes and the surrounding extracellular matrix. Matrix collagens and proteoglycans are synthesized by chondrocytes. They are hydroxylated, glycosylated, and proteolytically cleaved in the secretory pathway and further processed and assembled into cartilage matrix at the cell surface (9). Large complexes of proteoglycans are restricted in their mobility and swelling by a network of Col II and XI fibrils of high tensile strength. Interactions between the extracellular matrix and chondrocytes have been shown to be essential for cartilage development (10), and mutations in collagen genes can cause human chondrodysplasias (11,12).In addition to protein factors, lipids play an essential role in cartilage development. Deficiencies in cholesterol metabolism during embryogenesis can lead to severe skeletal abnormalities like Smith-Lemli-Opitz syndrome (for review, see ref. 13 and references therein). Similar chondrodysplasias have been observed in other vertebrates, including zebrafish (14, 15), in which the molecular mechanisms of skeletal development are conserved, including the roles of shh (16), patched (ptc) (17), bmp-...
BackgroundProliferation may predict response to neoadjuvant therapy of breast cancer and is commonly assessed by manual scoring of slides stained by immunohistochemistry (IHC) for Ki-67 similar to ER and PgR. This method carries significant intra- and inter-observer variability. Automatic scoring of Ki-67 with digital image analysis (qIHC) or assessment of MKI67 gene expression with RT-qPCR may improve diagnostic accuracy.MethodsKi-67 IHC visual assessment was compared to the IHC nuclear tool (AperioTM) on core biopsies from a randomized neoadjuvant clinical trial. Expression of ESR1, PGR and MKI67 by RT-qPCR was performed on RNA extracted from the same formalin-fixed paraffin-embedded tissue. Concordance between the three methods (vIHC, qIHC and RT-qPCR) was assessed for all 3 markers. The potential of Ki-67 IHC and RT-qPCR to predict pathological complete response (pCR) was evaluated using ROC analysis and non-parametric Mann-Whitney Test.ResultsCorrelation between methods (qIHC versus RT-qPCR) was high for ER and PgR (spearman´s r = 0.82, p < 0.0001 and r = 0.86, p < 0.0001, respectively) resulting in high levels of concordance using predefined cut-offs. When comparing qIHC of ER and PgR with RT-qPCR of ESR1 and PGR the overall agreement was 96.6 and 91.4%, respectively, while overall agreement of visual IHC with RT-qPCR was slightly lower for ER/ESR1 and PR/PGR (91.2 and 92.9%, respectively). In contrast, only a moderate correlation was observed between qIHC and RT-qPCR continuous data for Ki-67/MKI67 (Spearman’s r = 0.50, p = 0.0001). Up to now no predictive cut-off for Ki-67 assessment by IHC has been established to predict response to neoadjuvant chemotherapy. Setting the desired sensitivity at 100%, specificity for the prediction of pCR (ypT0ypN0) was significantly higher for mRNA than for protein (68.9% vs. 22.2%). Moreover, the proliferation levels in patients achieving a pCR versus not differed significantly using MKI67 RNA expression (Mann-Whitney p = 0.002), but not with qIHC of Ki-67 (Mann-Whitney p = 0.097) or vIHC of Ki-67 (p = 0.131).ConclusionDigital image analysis can successfully be implemented for assessing ER, PR and Ki-67. IHC for ER and PR reveals high concordance with RT-qPCR. However, RT-qPCR displays a broader dynamic range and higher sensitivity than IHC. Moreover, correlation between Ki-67 qIHC and RT-qPCR is only moderate and RT-qPCR with MammaTyper® outperforms qIHC in predicting pCR. Both methods yield improvements to error-prone manual scoring of Ki-67. However, RT-qPCR was significantly more specific.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-017-3111-1) contains supplementary material, which is available to authorized users.
BackgroundMammaTyper is a novel CE-marked in vitro diagnostic RT-qPCR assay which assigns routinely processed breast cancer specimens into the molecular subtypes Luminal A-like, Luminal B-like (HER2 positive or negative), HER2 positive (non-luminal) and Triple negative (ductal) according to the mRNA expression of ERBB2, ESR1, PGR and MKI67 and the St Gallen consensus surrogate clinical definition. Until now and regarding formalin-fixed, paraffin-embedded material (FFPE), this has been a task mostly accomplished by immunohistochemistry (IHC). However the discrepancy rates of IHC for the four breast cancer biomarkers are frequently under debate, especially for Ki-67 which carries the highest degree of inter- and even intra-observer variability. Herein we describe a series of studies in FFPE specimens which aim to fully validate the analytical performance of the MammaTyper assay, including the site to site reproducibility of the individual marker measurements.MethodsTumor RNA was extracted with the novel RNXtract RNA extraction kit. Synthetic RNA was used to assess the sensitivity of the RNXtract kit. DNA and RNA specific qPCR assays were used so as to determine analyte specificity of RNXtract. For the assessment of limit of blank, limit of detection, analytical measurement range and PCR efficiency of the MammaTyper kit serial dilutions of samples were used. Analytical precision studies of MammaTyper were built around two different real time PCR platforms and involved breast tumor samples belonging to different subtypes analyzed across multiple sites and under various stipulated conditions. The MammaTyper assay robustness was tested against RNA input variations, alternative extraction methods and tumor cell content.ResultsIndividual assays were linear up to at least 32.33 and 33.56 Cqs (quantification cycles) for the two qPCR platforms tested. PCR efficiency ranged from 99 to 109 %. In qPCR platform 1, estimates for assay specific inter-site standard deviations (SD) were between 0.14 and 0.20 Cqs accompanied by >94 % concordant single marker assignments for all four markers. In platform 2, the inter-site SD estimates were between 0.40 and 0.66 Cqs while the concordance for single marker assignments was >94 % for all four markers. The agreement reached between the two qPCR systems located in one site was 100 % for ERBB2, 96.9 % for ESR1, 97.2 % for PGR and 98.6 % for MKI67. RT-qPCR for individual markers was stable up to a 64-fold dilution for a typical clinical sample. There was no change in assay performance detected at the level of individual markers or subtypes after using different RNA isolation methods. The presence of up to 80 % of surrounding non-tumor tissue including in situ carcinoma did not affect the assay output. Sixteen out of 20 RNXtract eluates yielded more than 50 ng/μl of RNA (average RNA output: 233 ng/μl), whereas DNA contamination per sample was restricted to less than 15 ng/μl. Median recovery rate of RNA extraction was 91.0 %.ConclusionsIn this study the performance characteristics of MammaTyp...
The biological subtype of breast cancer influences the selection of systemic therapy. Distinction between luminal A and B cancers depends on consistent assessment of Ki-67, but substantial intra-observer and inter-observer variability exists when immunohistochemistry (IHC) is used. We compared RT-qPCR with IHC in the assessment of Ki-67 and other standard factors used in breast cancer subtyping. RNA was extracted from archival breast tumour tissue of 769 women randomly assigned to the FinHer trial. Cancer ESR1, PGR, ERBB2 and MKI67 mRNA content was quantitated with an RT-qPCR assay. Local pathologists assessed ER, PgR and Ki-67 expression using IHC. HER2 amplification was identified with chromogenic in situ hybridization (CISH) centrally. The results were correlated with distant disease-free survival (DDFS) and overall survival (OS). qPCR-based and IHC-based assessments of ER and PgR showed good concordance. Both low tumour MKI67 mRNA (RT-qPCR) and Ki-67 protein (IHC) levels were prognostic for favourable DDFS [hazard ratio (HR) 0.42, 95 % CI 0.25–0.71, P = 0.001; and HR 0.56, 0.37–0.84, P = 0.005, respectively] and OS. In multivariable analyses, cancer MKI67 mRNA content had independent influence on DDFS (adjusted HR 0.51, 95 % CI 0.29–0.89, P = 0.019) while Ki-67 protein expression had not any influence (P = 0.266) whereas both assessments influenced independently OS. Luminal B patients treated with docetaxel-FEC had more favourable DDFS and OS than those treated with vinorelbine-FEC when the subtype was defined by RT-qPCR (for DDFS, HR 0.52, 95 % CI 0.29–0.94, P = 0.031), but not when defined using IHC. Breast cancer subtypes approximated with RT-qPCR and IHC show good concordance, but cancer MKI67 mRNA content correlated slightly better with DDFS than Ki-67 expression. The findings based on MKI67 mRNA content suggest that patients with luminal B cancer benefit more from docetaxel-FEC than from vinorelbine-FEC.Electronic supplementary materialThe online version of this article (doi:10.1007/s10549-016-3835-7) contains supplementary material, which is available to authorized users.
BackgroundAccurate determination of the predictive markers human epidermal growth factor receptor 2 (HER2/ERBB2), estrogen receptor (ER/ESR1), progesterone receptor (PgR/PGR), and marker of proliferation Ki67 (MKI67) is indispensable for therapeutic decision making in early breast cancer. In this multicenter prospective study, we addressed the issue of inter- and intrasite reproducibility using the recently developed reverse transcription-quantitative real-time polymerase chain reaction-based MammaTyper® test.MethodsTen international pathology institutions participated in this study and determined messenger RNA expression levels of ERBB2, ESR1, PGR, and MKI67 in both centrally and locally extracted RNA from formalin-fixed, paraffin-embedded breast cancer specimens with the MammaTyper® test. Samples were measured repeatedly on different days within the local laboratories, and reproducibility was assessed by means of variance component analysis, Fleiss’ kappa statistics, and interclass correlation coefficients (ICCs).ResultsTotal variations in measurements of centrally and locally prepared RNA extracts were comparable; therefore, statistical analyses were performed on the complete dataset. Intersite reproducibility showed total SDs between 0.21 and 0.44 for the quantitative single-marker assessments, resulting in ICC values of 0.980–0.998, demonstrating excellent agreement of quantitative measurements. Also, the reproducibility of binary single-marker results (positive/negative), as well as the molecular subtype agreement, was almost perfect with kappa values ranging from 0.90 to 1.00.ConclusionsOn the basis of these data, the MammaTyper® has the potential to substantially improve the current standards of breast cancer diagnostics by providing a highly precise and reproducible quantitative assessment of the established breast cancer biomarkers and molecular subtypes in a decentralized workup.Electronic supplementary materialThe online version of this article (doi:10.1186/s13058-017-0848-z) contains supplementary material, which is available to authorized users.
Pathological staging and grading are crucial for risk assessment in non-muscle-invasive bladder cancer (NMIBC). Molecular grading might support pathological evaluation and minimize interobserver variability. In this study, the well-established breast cancer markers ESR1, PGR, ERBB2, and MKI67 were evaluated as potential molecular markers to support grading and staging in NMIBC. We retrospectively analyzed clinical data and formalin-fixed paraffin-embedded tissues (FFPE) of patients with NMIBC. Messenger RNA (mRNA) expression of the aforementioned markers was measured by single-step reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) using RNA-specific TaqMan assays. Relative gene expression was determined by normalization to two reference genes (CALM2 and B2M) using the 40 method and correlated to histopathological stage and grade. Pathological assessment was performed by an experienced uropathologist. Statistical analysis was performed using the SAS software JMP 9.0.0 version and GraphPad Prism 5.04. Of 381 cases of NMIBC, samples of 100 pTa and 255 pT1 cases were included in the final study. Spearman rank correlation revealed significant correlations between grade and expression of MKI67 (r = 0.52, p < 0.0001), ESR1 (r = 0.25, p < 0.0001), and ERBB2 (r = 0.18, p = 0.0008). In Mann-Whitney tests, MKI67 was significantly different between all grades (p < 0.0001), while ESR1 (p = 0.0006) and ERBB2 (p = 0.027) were significantly different between G2 and G3. Higher expression of MKI67 (r = 0.49; p < 0.0001), ERBB2 (r = 0.22; p < 0.0001), and ESR1 (r = 0.18; p = 0.0009) mRNA was positively correlated with higher stage. MKI67 (p < 0.0001), ERBB2 (p = 0.0058), and PGR (p = 0.0007) were significantly different between pTa and pT1. In NMIBC expression of ESR1, ERBB2 and MKI67 are significantly different between stage and grade. This potentially provides objective parameters for pathological evaluation.
Background/Aims/Objectives: It is difficult to identify patients with a non-muscle-invasive bladder cancer (NMIBC) at stage pT1 with concomitant carcinoma in situ (Cis) who will benefit from an early cystectomy. Methods: We retrospectively analyzed clinical data and formalin-fixed paraffin-embedded tissues of patients with NMIBC. Messenger ribonucleic acid (mRNA) expression of progesterone receptor (PGR), estrogen receptor (ESR1), ERBB2, and marker of proliferation Ki-67 (MKI67) was measured by single-step reverse transcription quantitative real-time polymerase chain reaction using RNA-specific TaqMan assays. Relative gene expression was determined by the normalization of 2 reference genes (CALM2, B2M) using the 40 ΔΔCT method and relative gene expression was correlated to the histopathological stage and oncological outcome. Results: Of 302 patients with pT1 NMIBC in the initial transurethral resection of the bladder, 65 had a concomitant Cis. Elevated ERBB2 expression (>40.1) significantly correlated with progress in patients with and without concomitant Cis (p = 0.020 and p = 0.049, respectively). For the subgroup of pT1 with concomitant Cis, elevated ERBB2 expression significantly discriminated between a high-risk group of 55% progression-free survival (PFS) and a low-risk group of 90% PFS after a 5-year follow-up (p = 0.020). Cox-regression analysis revealed ERBB2 expression as the only independent prognostic factor for PFS (p = 0.0037). Conclusions: High mRNA expression of ERBB2 can identify patients with pT1 NMIBC with concomitant Cis, who have a high risk of progression and might benefit from an early cystectomy.
Expression of ESR1, PGR, HER2 and Ki67 is important for risk stratification and therapy in breast cancer. Hormone receptor expression can also be found in MIBC, reflecting luminal and basal subtypes of breast cancer. Thus the purpose was to investigate on the mRNA expression of the aforementioned markers and their prognostic value in pT1 bladder cancer.Retrospective analysis of clinical data and Formalin-Fixed Paraffin-Embedded tissues (FFPE) of patients with stage pT1 NMIBC who underwent transurethral resection of the bladder was performed. mRNA expression was measured by single step RT-qPCR. Relative gene expression was determined by normalization to two housekeeping genes (CALM2, B2M) using the 40-ΔΔCT method. Correlation of mRNA expression with outcome was assessed using Kaplan-Meier analysis and multivariate Cox regression analysis.From overall 302 patients, 255 samples could be analyzed with valid measurements. Subtype distribution was Luminal-A in 11.4%, Luminal-B in 38.8%, triple negative in 36.9% and ERBB2 in 12.9%, respectively. Kaplan-Meier analysis revealed molecular subtyping being statistical significant for RFS (p=0.0408) and PFS (p=0.0039). Luminal-A patients did have the best RFS and PFS. Multivariate analysis revealed molecular subtyping to be significant for PFS (L-R Chi2 of 11.89, p=0.0078). Elevated expression of HER2 was statistically significant for PFS (p=0.0025) and discriminated among G3 tumors a high risk group (60% PFS) from a low risk risk group (90% PFS) after 5 year follow-up (p<0.001).Expression of ESR1, PGR and HER2 has predictive value in stage pT1 NMIBC and reveals potential therapeutic targets.
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