Applied Immunohistochemistry & Molecular Morphology最新文献

Odontogenic cysts and tumors exhibit a broad spectrum of biological characteristics. Despite recent advances in understanding the complex nature of these lesions, relatively less is known about the molecular markers involved in key pathogenic steps, such as proliferation and differentiation. This study aimed to elucidate the expression patterns of p63 and Ki-67 in odontogenic lesions, which may influence the management strategies. Forty-two specimens from the archives of the Histopathology Laboratory, including conventional ameloblastoma, unicystic ameloblastoma, odontogenic keratocysts, dentigerous cysts, and orthokeratinized cysts, were analyzed. Immunohistochemistry was performed using antibodies against p63 and Ki-67. Digital image analysis was performed using an Aperio slide scanner and QuPath software. Ki-67 levels were higher in odontogenic keratocysts (OKCs), indicating a greater proliferative index, whereas p63 expression was significantly higher in ameloblastomas and OKCs than in dentigerous cysts. No significant difference in p63 expression was observed between the ameloblastoma types. The results revealed variable Ki-67 and p63 expression in the odontogenic epithelium of the investigated odontogenic lesions, suggesting their potential roles in the biological behavior and aggressiveness of these lesions. This study highlights the differential expression pattern of Ki-67 and p63 and their potential involvement in the pathogenesis of these rare lesions. In addition, the study reinforces the need for more comprehensive molecular analyses using a larger sample. The results contribute to a better understanding of the complex nature of these lesions, which may facilitate improving the management options of odontogenic cysts and tumors.

The 2018 ASCO/CAP guidelines for HER2 testing for breast cancer implemented the addition of immunohistochemistry (IHC) directed in situ hybridization (ISH) recount to resolve equivocal results. The implementation of an additional 2+ IHC-directed ISH recount adds additional complexity to the testing workflow for an unclear impact on HER2 results. A retrospective review of all equivocal ISH cases (groups 2, 3, and 4) that underwent 2+ IHC-directed ISH, since the 2018 guidelines, which were finalized as either amplified or not amplified, was performed. HER2 group number and final HER2 amplification status frequently changed after IHC guided ISH assessment, which was due to significant changes in HER2/CEP17 ratio and average HER2 signal number per cell. Equivocal groups 2, 3, and 4 samples with a result of HER2 amplified after 2+ IHC-directed ISH counts were closer to the threshold for amplification on the original ISH count, yet their counts also increased significantly after IHC-directed count in comparison to those samples, which were not amplified. Groups 2 and 4 ISH counts significantly increased after IHC directed ISH for HER2/CEP17 ratio and HER2 signal number per cell. This study represents the most extensive examination of efforts to resolve equivocal HER2 ISH results, highlighting a significant shift in therapeutic options after IHC-guided ISH for a subset of breast cancer patients.

Claudin 18.2 is a transmembrane protein, part of the tight-junction complex, selectively expressed in gastric epithelium. It is showing promising results as a target in advanced gastric cancer in phase 3 clinical trials using a monoclonal antibody against claudin 18.2. A systematic review on expression of claudin 18.2 in gastric cancer was performed using the PubMed database. The following search expression was used: ("Stomach Neoplasms" [Mesh]) AND (("claudin-18[TIAB]") OR ("CLDN18[TIAB]")). A total of n=99 articles were retrieved. Of those, 17 preclinical studies about claudin 18.2 expression by immunohistochemistry were selected. The results of those studies showed great variability in the criteria used for defining the thresholds for positivity of the stain. The proportion of claudin 18.2 positive cases varied between 24% and 83%. In works using a positivity threshold set at >40% or >70% of cells with membranous/cytoplasmic staining at 2+/3+ intensity, the average rate of positive cases was 50% or 30%, respectively (similar with clones 43-14A and EPR19202). Positivity of claudin 18.2 was associated with advanced stage, diffuse phenotype and PD-L1 and EBV positivity in some of the studies. Variability in criteria used to define claudin 18.2 positivity, as well as methodological differences, could explain the variation in the proportion of positive cases described, as well as the inconsistency of the association with clinical, molecular, and survival variables. The upcoming anticlaudin 18.2 therapy in advanced gastric cancer should prompt pathology laboratories to adjust their staining protocols and evaluation criteria in their series of patients, to further establish the association of claudin expression with clinical and molecular variables.

The tumor immune microenvironment occupies an important position in gastric cancer. In this study, we investigated the relationship between indoleamine 2,3-dioxygenase 1 (IDO1), programmed cell death 1 ligand (PD-L1) expressioon, and CD8+ T-cell levels and their efficacy and prognostic value in preoperative gastric cancer specimens before neoadjuvant chemotherapy (NAC). A total of 162 patients with locally advanced gastric cancer were collected in this study. IDO1, PD-L1 expression, and CD8+ T-cell levels in the biopsy samples was detected by immunohistochemical staining, and the relationship between these indexes and the patients' clinicopathological parameters, chemotherapeutic efficacy, and prognosis were investigated. The IDO1 positivity rate was 43.2%. High expression of IDO1 was significantly associated with poor chemotherapeutic efficacy, lymph node metastasis (P<0.05). The PD-L1 positivity rate (using the combined positive score) was 38.2%, and was not related to any clinicopathological variable. Higher CD8+ T-cell levels were associated with a lower rate of lymph node metastasis and lower ypTNM stage (P<0.05). Higher CD8+ T-cell levels were negatively correlated with IDO1 expression (r=-0.224, P<0.05) and positively correlated with PD-L1 expression (r=0.254, P<0.05). Cox regression analysis demonstrated that higher CD8+ T-cell levels was an independent risk factor for overall survival (OS) and the expression of IDO1 had a significantly poorer disease-free survival (DFS). Overexpression of IDO1 and lower CD8+ T-cell levels were associated with poor survival in patients with gastric cancer who received neoadjuvant chemotherapy, and overexpression of IDO1 were associated with the poor tumor response. Our data suggest that IDO1 and CD8 testing of biopsy specimens might be a simple and effective prognostic biomarker for gastric cancer, and IDO1 could predict efficacy of neoadjuvant chemotherapy in gastric cancer.

Triple-negative breast cancer (TNBC) is challenging to treat because of its lack of specific molecular targets. The IMMUNOPEG study aimed to evaluate a novel structured method for interpreting TNBC immunohistochemistry specimens processed with VENTANA PD-L1 (SP142) assay. The study involved 10 pathologists who evaluated 50 different immunohistochemistry specimens of TNBC with programmed death ligand 1 (PD-L1) expression considered challenging and that were previously evaluated by the scientific committee, using the NAVIFY Digital Pathology platform. Initially, the overall percent agreement (OPA) was 74%, with a negative percent agreement (NPA) of 68.2% for samples classified as negative, and a positive percent agreement (PPA) of 94.5% for positive samples. After training on the method, the OPA improved significantly to 81.6%, with the NPA increasing to 80.5% and the PPA decreasing to 85.5%. The mean percentage of the tumor area occupied by PD-L1-stained immune cells decreased from 2.5% to 1.6% post-training, approaching to the scientific committee's consensus of 1.029%. The study found that the pathologists' confidence in their assessments increased significantly when using the structured method, which was found to be easy to use by 9 out of 10 pathologists. All pathologists agreed that the structured method was useful for assessing PD-L1 expression. The study suggests that this method has potential value in interpreting challenging cases of PD-L1 immunohistochemistry (IHC) in TNBC. Further refinement and a training protocol may be necessary to enhance the method's efficiency. The potential for generalizing this structured method to other IHC procedures and pathologies warrants additional research.

Colorectal cancer (CRC) is the most common gastrointestinal malignancy with a complicated behavior including relapse, metastasis, and development of resistance to chemotherapeutic drugs. Silent information regulator 2 homologue 1 (SIRT1), signal transducer and activator of transcription 3 (STAT3), and yes-associated protein (YAP) are cancer-related genes that have unclarified actions and even controversial roles in many human cancers including CRC. The current study aimed to evaluate the prognostic roles of SIRT1, STAT3, and YAP in CRC. Hundred and 13 CRC archival blocks were processed by TMA technique and immunostained with SIRT1, STAT3, and YAP antibodies. SIRT1, STAT3, and YAP are expressed in both tumor and stromal cells. SIRT1 expression in both the epithelial and stromal compartments was associated with favorable prognostic parameters, including longer overall and recurrence-free survival. In contrast, the epithelial and stromal expression of both STAT3 and YAP1 was associated with poor prognostic parameters, including short overall and recurrence-free survival. STAT3 and YAP epithelial expression showed a positive correlation with one another, but a negative correlation with epithelial SIRT1. While SIRT1 stromal expression was inversely correlated with stromal YAP expression, STAT3 and YAP concurrent stromal expression demonstrated a positive correlation with one another. There is crosstalk between CRC tumor and stromal cells by the coparallel expression of molecules such as SIRT1, STAT3, and YAP. There is a synergism between the STAT3 and YAP pathways in CRC at the level of the tumor and stroma. The tumor microenvironment of CRC could modulate tumor behavior by expressing markers suppressing invasion, such as SIRT1 or enhancing invasion, such as STAT3 and YAP.

N6-methyladenosine (m6A) is the most abundant epigenetic RNA modification in eukaryotes and plays a role in various cancers in humans. This m6A modification is regulated by m6A writers, erasers, and readers. One of the m6A erasers is α-ketoglutarate-dependent dioxygenase homolog 5 (ALKBH5). Previous studies have suggested that ALKBH5 is involved in the pathogenesis of head and neck squamous cell carcinoma. However, the role of ALKBH5 in odontogenic lesions has never been investigated. This study aimed to examine ALKBH5 expression in dental follicles (DFs), dentigerous cysts (DCs), odontogenic keratocyst (OKC), and ameloblastoma (AM) using immunohistochemistry. Six cases of DF, 20 cases of DC and OKC, respectively, and 30 cases of AM were included. The expression patterns, percentage of ALKBH5-positive cells, staining intensities, and immunoreactive scores were examined. ALKBH5 was mainly expressed in the nuclei of the epithelial cells in odontogenic lesions. The percentage of ALKBH5-positive cells was significantly higher in OKC and AM samples compared with DF samples ( P < 0.01). The percentage of ALKBH5-positive cells was also higher in OKC and AM samples than in DC samples; however, these results did not show statistical significance ( P > 0.05). ALKBH5 cell staining intensities and immunoreactive scores were significantly greater in OKC and AM samples than in DF and DC samples ( P < 0.01). Our results suggested that ALKBH5 might play a role in the pathogenesis of odontogenic lesions. Further investigation is needed to elucidate the precise molecular mechanism of the role of ALKBH5 in these diseases.

MYD88 L265P mutation is a gain-of-function driver mutation. It is observed in a significant proportion of Waldenstrom macroglobulinemia and activated B-cell subtype of diffuse large B-cell lymphoma (DLBCL; non-germinal center subtype). The incidence of this mutation in the subtypes of DLBCL has not yet been documented in the Pakistani population. This study aimed to ascertain the frequency and association of MYD88 L265P mutation within 2 subtypes of DLBCL, germinal center B-cell-like (GCB) and non-GCB B-cell lymphoma (non-GCB), in the local population. This cross-sectional study was conducted at the Armed Forces Institute of Pathology, Punjab, Pakistan. All newly diagnosed cases of DLBCL were included in the study. We analyzed 82 biopsy-proven cases of DLBCL (28 cases of GCB subtype and 54 cases of non-GCB subtype). DNA was extracted from formalin-fixed paraffin-embedded tissue blocks, and a conventional polymerase chain reaction was used to detect the MYD88 L265P mutation. The MYD88 L265P mutation was detected in 01 of 28 (3.6%) cases of the GCB subtype (95% CI: 0%-10%) and in 12 of 54 (22.2%) cases of the non-GCB subtype (95% CI: 11%-33%). Pearsos χ2 test revealed a statistically significant association of MYD88 L265P mutation with non-GCB subtype of DLBCL (P = 0.024). This association will assist in identifying a target population that may benefit from MYD88-specific treatment regimens. This may exponentially improve the outcome of patients with DLBCL harboring this mutation.

Mitochondrial ribosomal protein S5 (MRPS5) is abnormally expressed in various tumor tissues and may be a key molecule for the regulation of tumors. Our aim is to investigate the relationship between the expression of MRPS5 in clear cell renal cell carcinoma (ccRCC) and the prognosis of patients. MRPS5 expression in fresh tumoral tissues and peritumoral tissues of patients with ccRCC was examined by quantitative reverse transcription polymerase chain reaction, western blotting, and immunohistochemical staining, respectively. MRPS5 expression level in paraffin-embedded tumoral tissue samples with ccRCC was evaluated by immunohistochemical scoring criteria. The relationship between the expression of MRPS5 and the clinicopathological parameters and prognosis of patients with ccRCC was analyzed statistically. The expression of MRPS5 mRNA and protein in fresh tumoral tissues was lower than that in peritumoral tissues. Among 160 paraffin-embedded tumoral tissue samples, 99 cases (61.9%) showed high expression and 61 cases (38.1%) showed low expression of MRPS5. The expression level of MRPS5 was significantly correlated with T classification, TNM stage, and Fuhrman grade. Kaplan-Meier method and log-rank test indicated that patients with low MRPS5 expression had significantly poorer overall survival and recurrence-free survival than high MRPS5 expression. Multivariate analysis revealed that MRPS5 expression was an independent predictor of overall survival and recurrence-free survival, respectively. MRPS5 low expression was a risk factor for the prognosis of patients. The expression level of MRPS5 is significantly correlated with the postoperative survival status, which has the potential to be used as a novel prognostic biomarker for patients with ccRCC.

Introduction: In addition to mutations in KIT and PDGFRA, many other genetic alterations have been described in gastrointestinal stromal tumors (GISTs), including amplifications of C-MYC and EGFR, which are often associated with increased protein expression. The main of this study was to investigate the prognostic significance of C-MYC and EGFR expression in GISTs using immunohistochemistry (IHC).

Methods: We collected all GIST cases over a 16-year period. These cases were tested using antibodies against C-MYC (Leica, clone EP121) and EGFR (Leica, clone 113). C-MYC staining was assessed using the H-score method for nuclear, cytoplasmic, and combined staining. For EGFR staining (either cytoplasmic or nuclear), the intensity was graded as follows: 0 (no staining), 1 (weak staining), 2 (moderate staining), and 3 (strong staining). The percentage of positive cells was evaluated using a semiquantitative approach. Statistical analysis was performed using SPSS24.

Results: A total of 37 cases were included in our study. Nuclear expression of C-MYC was observed in 43% of the cases, with a high H-score in 43%. A statistically significant association was found between a high nuclear H-score for C-MYC and mitotic rate (P=0.046), as well as a high Ki-67 proliferation rate (P=0.046). However, no statistically significant associations were identified between the nuclear H-score of C-MYC and other clinical, pathologic, or survival data. Cytoplasmic expression of C-MYC was noted in 22% of cases, but no significant correlations were found with the clinicopathological data. EGFR staining was observed in 86% of cases, with a high score of 51%. EGFR expression was significantly associated with the mitotic index (P=0.012) and Ki-67 proliferation rate (P=0.046).

Conclusions: Our findings suggest that both C-MYC and EGFR may be overexpressed and/or amplified in GISTs, indicating their potential prognostic role. This could also pave the way for therapeutic strategies targeting these proteins.