Ki-67 Immunoreactivity Research Articles

Inhibition of cell proliferation by a selective inhibitor of the Ca2+-activated Cl− channel, Ano1

BackgroundIon channels play important roles in regulation of cellular proliferation. Ano1 (TMEM16A) is a Ca2+-activated Cl− channel expressed in several tumors and cell types. In the muscle layers of the gastrointestinal tract Ano1 is selectively expressed in interstitial cells of Cajal (ICC) and appears to be required for normal gastrointestinal slow wave electrical activity. However, Ano1 is expressed in all classes of ICC, including those that do not generate slow waves suggesting that Ano1 may have other functions. Indeed, a role for Ano1 in regulating proliferation of tumors and ICC has been recently suggested. Recently, a high-throughput screen identified a small molecule, T16Ainh-A01 as a specific inhibitor of Ano1. AimTo investigate the effect of the T16Ainh-A01 inhibitor on proliferation in ICC and in the Ano1-expressing human pancreatic cancer cell line CFPAC-1. MethodsInhibition of Ano1 was demonstrated by whole cell voltage clamp recordings of currents in cells transfected with full-length human Ano1. The effect of T16Ainh-A01 on ICC proliferation was examined in situ in organotypic cultures of intact mouse small intestinal smooth muscle strips and in primary cell cultures prepared from these tissues. ICC were identified by Kit immunoreactivity. Proliferating ICC and CFPAC-1 cells were identified by immunoreactivity for the nuclear antigen Ki67 or EdU incorporation, respectively. ResultsT16Ainh-A01 inhibited Ca2+-activated Cl− currents by 60% at 10μM in a voltage-independent fashion. Proliferation of ICC was significantly reduced in primary cultures from BALB/c mice following treatment with T16Ainh-A01. Proliferation of the CFPAC-1 human cell-line was also reduced by T16Ainh-A01. In organotypic cultures of smooth muscle strips from mouse jejunum, the proliferation of ICC was reduced but the total number of proliferating cells/confocal stack was not affected, suggesting that the inhibitory effect was specific for ICC. ConclusionsThe selective Ano1 inhibitor T16Ainh-A01 inhibited Ca2+-activated Cl− currents, reduced the number of proliferating ICC in culture and inhibited proliferation in the pancreatic cancer cell line CFPAC-1. These data support the notion that chloride channels in general and Ano1 in particular are involved in the regulation of proliferation.

Ki-67 Labeling Index as an Adjunct in the Diagnosis of Serous Tubal Intraepithelial Carcinoma

There is mounting evidence that serous tubal intraepithelial carcinoma (STIC) may be the immediate precursor of ovarian high-grade serous carcinoma (HGSC) but the criteria for its diagnosis are not well established as highlighted in a recent study showing that interobserver reproducibility, even among expert gynecologic pathologists, was moderate at best. Given the clinical significance of a diagnosis of STIC in a patient who has no other evidence of ovarian carcinoma, this is a serious issue that we felt needed to be addressed. Although it is not clear, at this time, whether such a patient should or should not be treated, the importance of an accurate and reproducible diagnosis of precursors of ovarian carcinoma cannot be underestimated. We hypothesized that an elevated Ki-67 labeling index may aid the diagnosis of STIC. Accordingly, we compared the Ki-67 index of STIC and HGSC to normal fallopian tube epithelium (FTE) in the same patients and to a control group of patients without carcinoma, matched for age. A total of 41 STICs were analyzed, of which 35 were associated with a concurrent HGSC. In FTE, immunoreactivity for Ki-67 was restricted to a few scattered cells (mean 2.0%). No statistically significant difference was found between patients with and without HGSC (P>0.05). However, both STICs and HGSC had significantly higher Ki-67 indices than normal FTE (P<0.0001). STICs uniformly had an elevated Ki-67 labeling index that ranged from 11.7% to 71.1% (average 35.6%). There was no correlation of the Ki-67 labeling index in the STICs and the associated HGSC, as the labeling index was lower in STIC in 18/35 (51.4%) whereas it was higher in 17/35 (48.6%) (P=0.86). In conclusion, the findings in this study indicate that compared with FTE, STICs have a significantly higher Ki-67 index similar to HGSC. Accordingly, the Ki-67 index can aid the diagnosis of intraepithelial tubal proliferations suspicious for STIC. Therefore, we propose that a Ki-67 index of 10% is a useful diagnostic tool to distinguish STICs from normal FTE.

Immunoreactivity of Ki-67/β-tubulin and immunocolocalization with active caspase-3 in rat dentate gyrus during postnatal development

This study was based on our previous report that the expression of active caspase-3 kept at a high level in dentate gyrus during postnatal development, which is not related to an apoptotic event. We addressed the hypothesis that the active caspase-3 expression may be related to a nonapoptotic role in the regulation of the cell cycle and differentiation or other physiological functions. To confirm this hypothesis, through a temporal investigation from postnatal day (P) 0, 4, 7, 10, 14, 21, 28, to 56, based on immunofluorescent method, we dual labeled active caspase-3 with Ki-67 or β-tubulin in the dentate gyrus. Our results showed a minority of active caspase-3 positive cells were colabeled with the proliferation marker Ki-67 in stratum moleculare (MOL), granular cell layer (GCL), subgranular zone (SGZ) and polymorphic stratum (POLY) from P0 to P14, and the colabeled cells decreased gradually with age. From P21 to P56, the colocalization of the two proteins was mainly focused on SGZ. There was a positive correlation between the positive cells of active caspase-3 with that of Ki-67. In addition, an extensive colocalization between active caspase-3 and β-tubulin was observed at all the age groups. There was a strong positive correlation between the intensity of active caspase-3 in GCL with that of β-tubulin in MOL, GCL and POLY of dentate gyrus and the stratum lucidum of CA3. Our data raised the possibility of a nonapoptotic role of active caspase-3 in dentate gyrus, which may be partly associated with cellular proliferation and differentiation, and also may be related to neurite outgrowth, axonal transport, or dendrite elongation of granular cells during postnatal development.

Dural angioleiomyoma of the middle cranial fossa: a case report and review of the literature

We describe a case of dural angioleiomyoma (ALM) of the middle cranial fossa. A 62-year-old man was referred to our center for fracture of the left clavicle because of a fall, and he had a sudden seizure during admission. The mass was completely resected. The tumor base was located at the bottom of the temporal lobe in the front of the petrous apex and near the cavernous sinus. After 7 months, the postoperative course demonstrated no tumor recurrence. The lesion had the typical appearance of ALM. Mitoses and necrosis were not identified. The lesion contained multifocality of fat in some areas of spindle-shaped cells, and markedly myxoid change was present. The spindle cells were positive for SMA and DES and negative for EMA, HMB-45, p53 and p16. A small focus of fat was positive for S-100. Less than 1% of the tumor cells showed immunoreactivity for Ki-67. EBV-encoded RNA was negative for tumor cells. Stainings for p53, p16, Ki-67 and EBV infection need to be carried out in cases of intracranial ALM because they are correlated with the biological behavior and prognosis of the tumor.

Intraductal tubulopapillary neoplasm of the pancreas on fine needle aspiration: Case Report with Differential Diagnosis

Intraductal tubulopapillary neoplasm (ITPN) is a rare primary pancreatic neoplasm accounting for less than 1% of all pancreatic exocrine neoplasms and 3% of intraductal neoplasms of the pancreas. Data on this entity are still limited. Here, we report a case of ITPN with cytopathologic and histopathologic findings. A 41-year-old woman with a 2.2 cm cyst in the head of the pancreas for five years was referred to our institution. The endoscopic ultrasound-guided fine-needle aspiration produced cytospins were moderately cellular with a few fragments of markedly atypical epithelium. The neoplastic cells displayed high-grade nuclear atypia with enlarged, eccentric nuclei, anisonucleosis and prominent nucleoli, irregular nuclear membranes, high nucleus to cytoplasmic (N/C) ratios, and a moderate amount of cytoplasm with no intracytoplasmic mucin. Histologically, the lesion was found to be an ITPN with focal high-grade dysplasia. No invasive carcinoma was identified. The neoplastic cells exhibited luminal immunolabeling for MUC-1, but were negative for MUC-2, trypsin, chymotrypsin, and P53. Approximately 5% of the neoplastic cells showed Ki-67 immunoreactivity. ITPN of pancreas may be a source of markedly atypical epithelial cells in pancreatic cystic aspiration. Clinical and radiographic findings, molecular mutational analysis, in combination with cytological features are essential to differentiate it from other disease entities.

Analysis of clinically relevant values of Ki-67 labeling index in Japanese breast cancer patients

It has become important to standardize the methods of Ki-67 evaluation in breast cancer patients, especially those used in the interpretation and scoring of immunoreactivity. Therefore, in this study, we examined the Ki-67 immunoreactivity of breast cancer surgical specimens processed and stained in the same manner in one single Japanese institution by counting nuclear immunoreactivity in the same fashion. We examined 408 Japanese breast cancers with invasive ductal carcinoma and studied the correlation between Ki-67 labeling index and ER/HER2 status and histological grade of breast cancer. We also analyzed overall survival (OS) and disease-free survival (DFS) of these patients according to individual Ki-67 labeling index. There were statistically significant differences of Ki-67 labeling index between ER positive/HER2 negative and ER positive/HER2 positive, ER negative/HER2 positive or ER negative/HER2 negative, and ER positive/HER2 positive and ER negative/HER2 negative groups (all P<0.001). There were also statistically significant differences of Ki-67 labeling index among each histological grade (P<0.001, respectively). As for multivariate analyses, Ki-67 labeling index was strongly associated with OS (HR 39.12, P=0.031) and DFS (HR 10.85, P=0.011) in ER positive and HER2 negative breast cancer patients. In addition, a statistically significant difference was noted between classical luminal A group and "20% luminal A" in DFS (P=0.039) but not between classical luminal A group and "25% luminal A" (P=0.105). A significant positive correlation was detected between Ki-67 labeling index and ER/HER2 status and histological grades of the cases examined in our study. The suggested optimal cutoff point of Ki-67 labeling index is between 20 and 25% in ER positive and HER2 negative breast cancer patients.

Enhancement of Urinary Bladder Carcinogenesis by the Role of Chronic Bacterial Infection-induced Inflammation (Imunnohistochemical and Biochemical studies)

Background: Bacterial infections traditionally have not been considered major causes of cancer. Recently, however, bacteria have been linked to cancer by two mechanisms: induction of chronic inflammation and production of carcinogenic bacterial metabolites. The most specific example of the inflammatory mechanism of carcinogenesis is Escherichia coliinfection. E. coli has been epidemiologically linked to urothelial carcinoma of the urinary bladder by its propensity to cause lifelong inflammation. This inflammation is in turn thought to cause cancer by inducing cell proliferation and production of mutagenic free radicals and N-nitroso compounds. Material and methods: After each 3, 6 and 9 months of daily oral administration ofdibutyl amine (DBA) plus sodium nitrate (nitrosamine precursors) in drinking water, curcuma in grinding diet and bladder injection with E. coli, rats were sacrificed. The excited bladder were dissected, processed and stained with H&E and anti-Ki67 immunohistochemical stains. This was followed by Elisa for caspse-3 and statistical analysis. Results: The current results indicated that E. coli infection in the bladder tissues increases the carcinogenic ability of nitrosamine precursors through caused marked alteration in the form hyperplastic, dysplastic and metaplastic urothelium. Also, there was a statistically significant increase in ki67 immunoreactivity in urothelium. However, a statistically significant decrease in the concentration of caspase-3 in bladder tissue consequently caused the process of carcinogenesis. All these changes were less marked after curcuma treatment when compared with the group that not treated with curcuma. Conclusion: Bacterial infection of the urinary bladder may play a major additive and possible role in bladder carcinogenesis. Rhizome of curcuma may have a protective action during induction of urinary bladder tumors.

Deletion of the epidermal growth factor receptor in renal proximal tubule epithelial cells delays recovery from acute kidney injury

To determine the role of epidermal growth factor receptor (EGFR) activation in renal functional and structural recovery from acute kidney injury (AKI), we generated mice with a specific EGFR deletion in the renal proximal tubule (EGFRptKO). Ischemia–reperfusion injury markedly activated EGFR in control littermate mice; however, this was inhibited in either the knockout or wild-type mice given erlotinib, a specific EGFR tyrosine kinase inhibitor. Blood urea nitrogen and serum creatinine increased to a comparable level in EGFRptKO and control mice 24 h after reperfusion, but the subsequent rate of renal function recovery was markedly slowed in the knockout mice. Twenty-four hours after reperfusion, both the knockout and the inhibitor-treated mice had a similar degree of histologic renal injury as control mice, but at day 6 there was minimal evidence of injury in the control mice while both EGFRptKO and erlotinib-treated mice still had persistent proximal tubule dilation, epithelial simplification, and cast formation. Additionally, renal cell proliferation was delayed due to decreased ERK and Akt signaling. Thus, our studies provide both genetic and pharmacologic evidence that proximal tubule EGFR activation plays an important role in the recovery phase after acute kidney injury.

An assessment of the diagnostic criteria for sessile serrated adenoma/polyps: SSA/Ps using image processing software analysis for Ki67 immunohistochemistry

BackgroundSerrated polyps belong to a heterogeneous group of lesions that are generally characterized morphologically. This type of lesion is thought to be the precursor of sporadic carcinomas with microsatellite instability, and probably also the precursor for CpG island-methylated microsatellite-stable carcinomas. For practical purposes, according to the 2010 WHO classification, the diagnostic criteria for sessile serrated adenomas/polyps (SSA/Ps) was established by the research project “Potential of Cancerization of Colorectal Serrated Lesions” led by the Japanese Society for Cancer of the Colon and Rectum. The aim of this study was to evaluate the validity of the morphologic characteristics established in Japan by using immunohistochemical staining for Ki-67.MethodsTo calculate the target cells, 2 contiguous crypts which could be detected from the bottom of the crypt to the surface of the colorectal epithelium were selected. To validate the proliferative activity, we evaluated the percentage and the asymmetrical staining pattern of Ki67 positive cells in each individual crypt. To examine the immunoreactivity of Ki67, computer-assisted cytometrical analysis was performed.ResultsSSA/Ps had a higher proliferative activity as compared to hyperplastic polyps (HPs) based on the difference in incidence of Ki67 positive cells, and the former also exhibited a significantly higher asymmetric distribution of these cells as compared to HPs, even in lesions with a diameter <10 mm.ConclusionWe conclude that assessment of the pathological findings of SSA/Ps, including crypt dilation, irregularly branching crypts, and horizontally arranged basal crypts (inverted T- and/or L-shaped crypts) is appropriate to show a significantly higher proliferative activity as compared to HPs. Further, the use of two-dimensional image analysis software is an objective and reproducible method for this type of histological examination.Virtual slidesThe virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/6718091416698112

Angiotensin‐(1‐7) reduces proliferation and angiogenesis of human prostate cancer xenografts with a decrease in angiogenic factors and an increase in sFlt‐1

Prostate cancer is the most frequently diagnosed malignancy and the second-leading cause of cancer death in men. The purpose of this study was to determine the anti-proliferative and anti-angiogenic efficacy of angiotensin-(1-7) [Ang-(1-7)], an endogenous peptide hormone, in human prostate cancer xenografts. Human LNCaP prostate cancer cells were injected into the flank of athymic mice and tumors were treated with Ang-(1-7) for 54 days. Tumor growth and angiogenesis were determined by immunohistochemistry and western blot hybridization. Ang-(1-7) markedly reduced the volume and wet weight of LNCaP xenograft tumors. Histological analysis of tumor sections from saline-treated mice showed increased Ki67 immunoreactivity and enhanced phosphorylation of the MAP kinases ERK1/2 compared to tumors from Ang-(1-7)-treated mice, suggesting that the heptapeptide reduces cell proliferation. Intratumoral vessel density was decreased in Ang-(1-7)-treated mice with an associated reduction in vascular endothelial growth factor (VEGF) and placental growth factor (PlGF), suggesting that the heptapeptide attenuates vascularization by reducing angiogenic factors. Ang-(1-7) administration markedly increased the soluble fraction of VEGF receptor 1 (sFlt-1), with a concomitant reduction in VEGF receptors 1 and 2. sFlt-1 serves as a decoy receptor that traps VEGF and PlGF, making the ligands unavailable to membrane-bound VEGF receptors and preventing activation of pro-angiogenic signaling. The decrease in PlGF and VEGF coupled with the increase in sFlt-1 suggests that Ang-(1-7) may serve as a novel anti-angiogenic therapy for prostate cancer. Further, the pleiotropic mechanisms of action by Ang-(1-7) may limit angiogenic resistance that occurs with VEGF inhibitors or receptor blockers.

Su1126 Omeprazole Blocksth2-Cytokine-Stimulated Secretion of Eotaxin-3 in Esophageal Squamous Cells From Patients With EoE and From Patients With GERD

Eosinophilic esophagitis (EoE) has been recognized as a chronic disease of the esophagus in children and adults. Chronic inflammation of the esophagus may lead to malignant transformation of cells. Malignant or pre-malignant (dysplasia) conditions of the esophagus in EoE has not been reported. p53, a mutated intracellular oncogene marker, and Ki-67, a nuclear antigen associated with cell proliferation, were found to be increased in patients with Barrett's esophagus and esophageal cancer. Aim: To evaluate the presence of p53 and Ki-67 in children with EoE. Materials: Esophageal biopsies of children with EoE (Test Group), children with GERD (Control 1), adults with EoE (Control 2), adults with esophageal cancer (Control 3), and children with normal esophagus (Control 4), comprised our patient population. The immunreactivity of monoclonal oncogene p53 (DAKO, DO-7) and monoclonal Ki-67 cell marker (DAKO, Clone MIB-1) were utilized. Immunoreactivity of p53 was considered positive when at least 10% of the cells stained positive (Wang 1993). Ki-67 immunoreactivity was calculated as a percentage of positive cells per at least 500 cells (Feith 2004). Results: A total of 50 esophageal biopsies were available, 25 children with EoE, 15 children with GERD, 15 children with normal esophagus, 3 adults with EoE, and 2 adults with esophageal cancer. p53 was negative in normal mucosa but was Ki-67 positive in the basal layer (proliferative zone). Adult biopsies with esophageal cancer were positive for both markers. Immunoreactivity of p53 and Ki-67 was significantly higher in EoE vs. normal esophagus (Table). Conclusion: Oncogene p53 and Ki-67 immunoreactivity were higher in the EoE compared to the GERD and the normal group. Our data suggested an active cell proliferation in the esophagus of children with EoE and GERD. Whether the positive immunoreactivity of p53 in EoE children represents a real genetic mutation or false positive results is yet to be resolved (Rice 1994). Oncogene immunoreactivity in EoE

Su1125 Tumor Suppressive Gene p-53 and Cell Proliferation Marker KI-67 in Children With Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) has been recognized as a chronic disease of the esophagus in children and adults. Chronic inflammation of the esophagus may lead to malignant transformation of cells. Malignant or pre-malignant (dysplasia) conditions of the esophagus in EoE has not been reported. p53, a mutated intracellular oncogene marker, and Ki-67, a nuclear antigen associated with cell proliferation, were found to be increased in patients with Barrett's esophagus and esophageal cancer. Aim: To evaluate the presence of p53 and Ki-67 in children with EoE. Materials: Esophageal biopsies of children with EoE (Test Group), children with GERD (Control 1), adults with EoE (Control 2), adults with esophageal cancer (Control 3), and children with normal esophagus (Control 4), comprised our patient population. The immunreactivity of monoclonal oncogene p53 (DAKO, DO-7) and monoclonal Ki-67 cell marker (DAKO, Clone MIB-1) were utilized. Immunoreactivity of p53 was considered positive when at least 10% of the cells stained positive (Wang 1993). Ki-67 immunoreactivity was calculated as a percentage of positive cells per at least 500 cells (Feith 2004). Results: A total of 50 esophageal biopsies were available, 25 children with EoE, 15 children with GERD, 15 children with normal esophagus, 3 adults with EoE, and 2 adults with esophageal cancer. p53 was negative in normal mucosa but was Ki-67 positive in the basal layer (proliferative zone). Adult biopsies with esophageal cancer were positive for both markers. Immunoreactivity of p53 and Ki-67 was significantly higher in EoE vs. normal esophagus (Table). Conclusion: Oncogene p53 and Ki-67 immunoreactivity were higher in the EoE compared to the GERD and the normal group. Our data suggested an active cell proliferation in the esophagus of children with EoE and GERD. Whether the positive immunoreactivity of p53 in EoE children represents a real genetic mutation or false positive results is yet to be resolved (Rice 1994). Oncogene immunoreactivity in EoE

Nek2A contributes to tumorigenic growth and possibly functions as potential therapeutic target for human breast cancer

Nek2A (NIMA-related kinases 2A) has been known as an important centrosome regulatory factor. The aim of this study was to investigate the expression of Nek2A and the role it played in different stages of breast cancer. We detected the expression of Nek2A in both mRNA and protein levels in MCF10 cell lines including MCF-10A, MCF-10DCIS.com, MCF-10CA1a and in human breast samples which contained normal breast tissue (NBT), breast ductal carcinoma in situ (DCIS), and invasive ductal carcinoma (IDC). Our study revealed that the mRNA and protein expression of Nek2A were significantly up-regulated in MCF-10DCIS.com and MCF-10CA1a cell lines as well as in human primary breast cancer tissue (DCIS and IDC). Our study also presented a correlation between Nek2A mRNA expression and some clinic pathological factors. We found that Nek2A mRNA expression was associated with molecular subtypes, ER, PR and Ki-67 immunoreactivity (P<0.05) in DCIS and associated with histological grade, lymph node metastasis, molecular subtypes, c-erbB-2, and Ki-67 expression (P<0.05) in IDC. In addition, we observed that ectopic expression of Nek2A in "normal" immortalized MCF-10A breast epithelial cell resulted in increased Nek2A which lead to abnormal centrosomes. Furthermore, knockdown of Nek2A in MCF-10DCIS.com could remarkably inhibit cell proliferation and induce cell cycle arrest in MCF-10DCIS.com cell line. These data suggested that Nek2A might bear a close relationship with development and progression of breast carcinoma, and highlighted its role as a novel potential biomarker for diagnosis and a possible therapeutic target for human breast cancer especially for DCIS.

Effects of acrylamide exposure on serum hormones, gene expression, cell proliferation, and histopathology in male reproductive tissues of Fischer 344 rats

Acrylamide (AA) is a reactive monomer used in many technological applications, but it is the incidental formation during cooking of common starchy foods that leads to pervasive human exposure, typically in the range of 1μg/kg body weight (bw)/day (d). AA is carcinogenic in multiple organs from both sexes of several rodent models and a consistent body of evidence points to a genotoxic mechanism based on metabolism to a DNA-reactive epoxide, glycidamide (GA). In F344 rats, tumorigenesis occurs in several hormonally regulated tissues (thyroid, mammary gland, and peri-testicular mesothelium), which has prompted speculation about endocrine dysregulation as a possible mechanism. The present study evaluated the effects of a 14d exposure to AA administered through the drinking water on reproductive tissues and the hypothalamic-pituitary-testes (HPG) axis in male F344 rats. The doses selected encompass a range from approximately 2.5mg/kgbw/d, which is carcinogenic after lifetime exposure, to 50mg/kgbw/d, a maximally tolerable dose that causes hind limb paralysis. AA caused significant changes in serum hormones, histopathology, testicular gene expression, and cell proliferation, especially at the highest dose. Despite strong evidence for activation of the HPG axis subsequent to decreases in testosterone levels, and histopathological changes associated with significant effects on Leydig and germ cells, with concomitant mRNA expression changes, the precise mechanism(s) for AA-induced testicular toxicity remains unclear; however, the absence of evidence for increased proliferation of the peri-testicular mesothelium (Ki-67 immunoreactivity) does not support hormonal dysregulation as a contributing factor to the predisposition of this tissue to the carcinogenic effects of AA.

Segment- and cell-specific expression of D-type cyclins in the postnatal mouse epididymis

Sperm transport, maturation and storage are the essential functions of the epididymis. The epididymis in the mouse is structurally characterized by regional and segmental organization including caput, corpus and cauda epididymis that are comprised of 10 segments. Although several growth factor signaling pathways have been discovered in the epididymis, how these converge onto the cell cycle components is unknown. To begin to elucidate the growth factor control of cell cycle events in the epididymis, we analyzed the expression of D-type cyclins at different postnatal ages. At 7d, cyclin D1 was mainly expressed in the cauda epithelium, by 14d its expression occurred in the epithelium of caput, corpus and cauda that persisted up to 21d. By 42d, cyclin D1 was mostly detectable in the principal cells of the caput and corpus (segments 1–7) but not in the cauda epididymis. Expression of cyclin D2, unlike that of cyclin D1, was evident only at 42d but not earlier, and was mostly confined to corpus and cauda epithelium. In contrast to both cyclins D1 and D2, cyclin D3 was expressed primarily in the interstitium at 7d and by 21d its expression was localized to the epithelium of the corpus and cauda epididymis. By 42d, expression of cyclin D3 peaked in segments 6–10 and confined to basal and principal cells of the corpus and apical cells of the cauda epithelium. Ki67 immunoreactivity confirmed absence of cell proliferation despite continued expression of D-type cyclins in the adult epididymis. Collectively, on the basis of our immunophenotyping and protein expression data, we conclude that the D-type cyclins are expressed in a development-, segment-, and cell-specific manner in the postnatal mouse epididymis.

Fluctuations in cell proliferation, apoptosis, and cell cycle regulation at the early stage of tumor promotion in rat two-stage carcinogenesis models

We previously demonstrated that 28-day administration of carcinogens that evoked cell proliferation as determined by immunoreactivity for Ki-67 or minichromosome maintenance 3 (Mcm3), in many target organs, increased the numbers of topoisomerase (Topo) IIα(+), ubiquitin D (Ubd)(+), and TUNEL(+) apoptotic cells. We also found increased co-expression of Topo IIα and Ubd, suggestive of increased spindle checkpoint disruption at the M phase. To investigate the roles of these markers in the early stages of carcinogenesis, we examined distribution changes in several carcinogenic target organs using rat initiation-promotion models. Promoting agents targeting the liver (piperonyl butoxide, methapyrilene hydrochloride), thyroid (sulfadimethoxine), urinary bladder (phenylethyl isothiocyanate), and forestomach and glandular stomach (catechol) were administered to rats after initiation treatment for each target organ. Numbers of Ki-67(+), Mcm3(+), Topo IIα(+) and TUNEL(+) cells increased within preneoplastic lesions as determined by glutathione S-transferase placental form in the liver or phospho-p44/42 mitogen-activated protein kinase in the thyroid, and hyperplastic lesions having no known preneoplastic markers in the urinary bladder, forestomach and glandular stomach. On the other hand, Ubd(+) cells did not increase within these preneoplastic lesions, but increased within hyperplastic lesions. These results suggest that both cell proliferation and apoptosis may be involved in the formation of preneoplastic lesions in the liver and thyroid examined here; however, spindle checkpoint disruption may not be involved in this process. Changes in hyperplastic lesions of the urinary bladder, forestomach and glandular stomach are similar to the 28-day carcinogen-treated cases, suggestive of the hyperplastic cellular character before the preneoplastic state.

Ozone Exposure Suppresses Proliferative Response in Mice Skin

Ozone Exposure Suppresses Proliferative Response in Mice Skin

Immunohistochemical study of osteopontin, Ki-67, and CD34 of psoriasis in Mansoura, Egypt

Psoriasis is a chronic inflammatory skin disease characterized by hyper-proliferation, abnormal differentiation, and inflammatory infiltration in epidermis and dermis. We planned this study to analyze probable associations between Osteopontin (OPN), Ki-67, CD34, and histopathological features in psoriasis. We studied OPN expression and its correlation with Ki-67 and CD34 expression in lesional, non-lesional skin, and normal skin. Immunoreactivity for OPN and Ki-67 was based on the level of epidermal staining. CD34 expression was scored as mild, moderate, and strong, according to the number of stained dermal capillaries. Our results showed statistically significant differences in the expression of OPN, Ki-67, and CD34 between lesional and non-lesional skin as well as between non-lesional skin and control group (P ≤ 0.001). In addition, there was a significant difference in the expression of OPN, Ki-67, and CD34 between control and lesional group (P=0.02, P=0.02, and P=0.04, respectively). OPN expression seems to be related to Ki-67 (proliferation index) and CD34 expression (angiogenesis marker) confirming its role in the pathogenesis of psoriasis. Then "anti- OPN and anti-angiogenesis" may eventually become a useful therapeutic approach in psoriasis.

Intraductal neoplasm of the intrahepatic bile duct: Clinicopathological study of 24 cases

To investigate the clinicopathological features of intraductal neoplasm of the intrahepatic bile duct (INihB). Clinicopathological features of 24 cases of INihB, which were previously diagnosed as biliary papillomatosis or intraductal growth of intrahepatic biliary neoplasm, were reviewed. Mucin immunohistochemistry was performed for mucin (MUC)1, MUC2, MUC5AC and MUC6. Ki-67, P53 and β-catenin immunoreactivity were also examined. We categorized each tumor as adenoma (low grade), borderline (intermediate grade), and malignant (carcinoma in situ, high grade including tumors with microinvasion). Among 24 cases of INihB, we identified 24 tumors. Twenty of 24 tumors (83%) were composed of a papillary structure; the same feature observed in intraductal papillary neoplasm of the bile duct (IPNB). In contrast, the remaining four tumors (17%) showed both tubular and papillary structures. In three of the four tumors (75%), macroscopic mucin secretion was limited but microscopic intracellular mucin was evident. Histologically, 16 tumors (67%) were malignant, three (12%) were borderline, and five (21%) were adenoma. Microinvasion was found in four cases (17%). Immunohistochemical analysis revealed that MUC1 was not expressed in the borderline/adenoma group but was expressed only in malignant lesions (P = 0.0095). Ki-67 labeling index (LI) was significantly higher in the malignant group than in the borderline/adenoma group (22.2 ± 15.5 vs 7.5 ± 6.3, P < 0.01). In the 16 malignant cases, expression of MUC5AC showed borderline significant association with high Ki-67 LI (P = 0.0622). Nuclear expression of β-catenin was observed in two (8%) of the 24 tumors, and these two tumors also showed MUC1 expression. P53 was negative in all tumors. Some cases of INihB have a tubular structure, and are subcategorized as IPNB with tubular structure. MUC1 expression in INihB correlates positively with degree of malignancy.

P53/MDM2 co-expression correlates with the tumour differentiation in oral squamous cell carcinoma - a retrospective study and a systematic review

Background: MDM2 and p53 are involved in a negative feedback loop where p53 regulates MDM2 at the transcriptional level. MDM2, in turn, downregulates p53. This co-ordinated interaction between these proteins is set to play an important role in the regulation of cell cycle progression following DNA damage to cells. The over-expression of both p53 and MDM2 has been reported in various cancers. However there are only few studies discussing the co-expression of MDM2 with p53 in oral squamous cell carcinoma Aim: The purpose of this study was to determine the correlation of co-expression of p53, MDM2, and Ki-67 proteins with clinico-pathological factors in oral squamous cell carcinoma (OSCC) and to conduct a systematic review of the co-expression of p53/MDM2. Method: This is a retrospective descriptive study and a systematic review. Formalin-fixed paraffinembedded tissues from 45 OSCC cases were stained by immunohistochemistry (IHC) for p53, MDM2, and Ki-67 proteins. Results: Immuno-reactivity for p53, MDM2, and Ki-67 was seen in 75.6%, 97.8%, and 62.2% cases of OSCC respectively. The co-expression of p53 and MDM2 (p53/MDM2) was detected in 97.1%, however there was no significant correlation between p53 and MDM2 expression. Notably, p53/MDM2 coexpression was significantly associated with tumour differentiation (p-value = 0.045). The Ki-67LI was not significantly associated with neither MDM2 nor p53/MDM2 co-expression (p-value = 0.268, 0.916 respectively). Conclusion: The expression of MDM2 was not signif icantly associated with p53 expression suggesting that MDM2 expression is mediated by p53-independent pathways or mutated p53 could not induce the expression of MDM2 in this set of OSCCs. The only clinico-pathological parameter that correlates significantly with co-expression of p53/MDM2 is tumour differentiation where it is suggestive that the co-expression of these 2 proteins is indicative of aggressive tumour behavior.