Subcellular localization of hTERT in breast cancer: insights into its tumorigenesis and drug resistance mechanisms in HER2-immunopositive breast cancer.

Human telomerase reverse transcriptase (hTERT) is highly expressed in various cancers, including breast cancer. Although telomere elongation is an essential role for hTERT, the nuclear export after oxdative stress has also been shown in several cancer cell lines and is associated with drug-resistance in vitro. As only a few reports focused on the subcellular localization of hTERT in clinical specimens, we performed immunohistochemistry (IHC) and analyzed the correlation between intracellular hTERT expression and the clinicopathological characteristics to identify the clinical significance of hTERT subcellular expression in breast cancers. 144 invasive breast cancers classified by IHC subtype without primary systemic therapy (PST), were selected from a surgical resection cohort and were immunostained for hTERT, p-STAT3, p-AKT and p-ERK. The nuclear and/or cytoplasmic staining intensity and proportion of hTERT were scored and compared with clinicopathological parameters. The nuclear hTERT expression was significantly correlated with HER2 expression (p = 0.00156), and the scores were significantly correlated with p-STAT3 and p-AKT expression scores (r = 0.532, p = 0.000587 and r = 0.345, p = 0.0339, respectively) in the HER2-immunopositive breast cancer including luminal-HER2 and HER2 subtypes. Furthermore, hTERT was expressed more in cytoplasm in the specimens after PST than those before PST, and the score tended to be negatively correlated with tumor shrinkage rate in HER2 subtype (r = -0.593, p = 0.0705). These results suggest that nuclear and/or cytoplasmic hTERT may play a different role before and after PST including the tumorigenesis and drug-resistance in breast cancer. Suppression of cytoplasmic hTERT expression may lead to more effective strategy for drug-resistant HER2 subtype in breast cancer.

Morphometrical Differences among Endometrial Endometrioid Carcinoma Grade 1, Grade 3, and Serous Carcinoma in Endometrial Liquid-Based Cytology Preparations.

INTRODUCTION: In Japan, the direct smearing preparation (conventional preparation) has been widely used for cytological examination of the endometrium. Problems with the conventional preparation can be dissolved by liquid-based cytology (LBC) preparation. The Yokohama System is a method for reporting endometrial cytology, but the system lumps cancers together and does not distinguish between histological types. The objective of this study was to clarify morphometrical differences among endometrial endometrioid carcinoma grade 1 (G1), grade 3 (G3), and serous carcinoma (Serous) by image analysis of endometrial LBC. METHODS: Using Papanicolaou smears prepared by LBC after sampling with a brush from 32 G1, 16 G3, and 16 Serous patients, image analysis was performed concerning the following 11 items: (1) number of layers of cluster, (2) area of cluster, (3) perimeter of cluster, (4) roundness of cluster, (5) complexity of cluster, (6) area of nucleus, (7) perimeter of nucleus, (8) roundness of nucleus, (9) complexity of nucleus, (10) area of nucleolus, and (11) nucleolus/nucleus (N/N) ratio. The data were statistically compared among G1, G3, and Serous. RESULTS: Significant differences were observed in the number of layers of cluster (G1G3G3, G1>Serous), complexity of cluster (G1Serous), and N/N ratio (G1>G3, G3

Mutant GNAS limits tumor aggressiveness in established pancreatic cancer via antagonizing the KRAS-pathway.

BACKGROUND: Mutations in GNAS drive pancreatic tumorigenesis and frequently occur in intraductal papillary mucinous neoplasm (IPMN); however, their value as a therapeutic target is yet to be determined. This study aimed at evaluating the involvement of mutant GNAS in tumor aggressiveness in established pancreatic cancer. METHODS: CRISPR/Cas9-mediated GNAS R201H silencing was performed using human primary IPMN-associated pancreatic cancer cells. The role of oncogenic GNAS in tumor maintenance was evaluated by conducting cell culture and xenograft experiments, and western blotting and transcriptome analyses were performed to uncover GNAS-driven signatures. RESULTS: Xenografts of GNAS wild-type cells were characterized by a higher Ki-67 labeling index relative to GNAS-mutant cells. Phenotypic alterations in the GNAS wild-type tumors resulted in a significant reduction in mucin production accompanied by solid with massive stromal components. Transcriptional profiling suggested an apparent conflict of mutant GNAS with KRAS signaling. A significantly higher Notch intercellular domain (NICD) was observed in the nuclear fraction of GNAS wild-type cells. Meanwhile, inhibition of protein kinase A (PKA) induced NICD in GNAS-mutant IPMN cells, suggesting that NOTCH signaling is negatively regulated by the GNAS-PKA pathway. GNAS wild-type cells were characterized by a significant invasive property relative to GNAS-mutant cells, which was mediated through the NOTCH regulatory pathway. CONCLUSIONS: Oncogenic GNAS induces mucin production, not only via MUC2 but also via MUC5AC/B, which may enlarge cystic lesions in the pancreas. The mutation may also limit tumor aggressiveness by attenuating NOTCH signaling; therefore, such tumor-suppressing effects must be considered when therapeutically inhibiting the GNAS pathway.

Outer Cutoff Value for the Box-Counting Method for Fractal Analysis of the Nucleus Using Kirsch Edge Detection.

OBJECTIVE: The complexity of chromatin (i.e., irregular geometry and distribution) is one of the important factors considered in the cytological diagnosis of cancer. Fractal analysis with Kirsch edge detection is a known technique to detect irregular geometry and distribution in an image. We examined the outer cutoff value for the box-counting (BC) method for fractal analysis of the complexity of chromatin using Kirsch edge detection. MATERIALS: The following images were used for the analysis: (1) image of the nucleus for Kirsch edge detection measuring 97 × 122 pix (10.7 × 13.4 µm) with a Feret diameter of chromatin mesh (n = 50) measuring 17.3 ± 1.8 pix (1.9 ± 0.5 µm) and chromatin network distance (n = 50) measuring 4.4 ± 1.6 pix (0.49 ± 0.18 µm), and (2) sample images for Kirsch edge detection with varying diameters (10.4, 15.9, and 18.1 µm) and network width of 0.4 µm. METHODS: Three types of bias that can affect the outcomes of fractal analysis in cytological diagnosis were defined. (1) Nuclear position bias: images of 9 different positions generated by shifting the original position of the nucleus in the middle of a 256 × 256 pix (28.1 µm) square frame in 8 compass directions. (2) Nuclear rotation bias: images of 8 different rotations obtained by rotating the original position of the nucleus in 45° increments (0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315°). (3) Nuclear size bias: images of varying size (diameter: 190 pix [10.4 µm], 290 pix [15.9 µm], and 330 pix [18.1 µm]) with the same mesh pattern (network width: 8 pix [0.4 µm]) within a 512 × 512 pix square. Different outer cutoff values for the BC method (256, 128, 64, 32, 16, and 8 pix) were applied for each bias to assess the fractal dimension and to compare the coefficient of variation (CV). RESULTS: The BC method with the outer cutoff value of 32 pix resulted in the least variation of fractal dimension. Specifically, with the cutoff value of 32 pix, the CV of nuclear position bias, nuclear rotation bias, and nuclear size bias were <1% (0.1, 0.4, and 0.3%, respectively), with no significant difference between the position and rotation bias (p = 0.19). Our study suggests that the BC method with the outer cutoff value of 32 pix is suitable for the analysis of the complexity of chromatin with chromatin mesh.

Bmi-1 Immunohistochemical Expression in Endometrial Carcinoma is Correlated with Prognostic Activity.

Background and objectives: B-lymphoma Mo-MLV insertion region 1 (Bmi-1) is a stem cell factor that is overexpressed in various human cancer tissues. It has been implicated in cancer cell proliferation, cell invasion, distant metastasis, and chemosensitivity, and is associated with patient survival. Several reports have also identified Bmi-1 protein overexpression in endometrial carcinoma; however, the relationship between Bmi-1 expression and its significance as a clinicopathological parameter is still insufficiently understood. Accordingly, the present study aimed to clarify whether immunohistochemical staining for Bmi-1 in human endometrial carcinoma and normal endometrial tissues can be used as a prognostic and cell proliferation marker. Materials and Methods: Bmi-1 expression was assessed in endometrioid carcinoma (grade 1-3) and normal endometrial tissues (in the proliferative and secretory phases) by immunohistochemistry; protein expression was evaluated using the nuclear labeling index (%) in the hot spot. Furthermore, we examined other independent prognostic and proliferation markers, including the protein levels of Ki-67, p53, and cyclin A utilizing semi-serial sections of endometrial carcinoma tissues. Results: The expression of the Bmi-1 protein was significantly higher in all grades of endometrial carcinoma than in the secretory phase of normal tissues. Moreover, Bmi-1 levels tended to be higher in G2 and G3 tissues than in G1 tissue, without reaching significance. Bmi-1 expression showed no notable differences among International Federation of Gynecology and Obstetrics (FIGO) stages in endometrial carcinoma. Furthermore, we observed a significant positive relationship between Bmi-1 and Ki-67, cyclin A, or p53 by Spearman's rank correlation test, implying that high Bmi-1 expression can be an independent prognostic marker in endometrial carcinoma. Conclusions: Our study suggests that Bmi-1 levels in endometrial carcinoma tissues may be useful as a reliable proliferation and prognostic biomarker. Recently, the promise of anti-Bmi-1 strategies for the treatment of endometrial carcinoma has been detected. Our results provide fundamental data regarding this anti-Bmi-1 strategy.