P16/Ki-67 Immunostaining in the Triage of Postmenopausal Women With Low-Grade Cytology Results.

OBJECTIVE: The interpretation of postmenopausal smears and the gynecological treatment of these patients can often be difficult. The objective of this study was to assess the performance of p16/Ki-67 dual-stained cytology as a triage of atypical squamous cells of undetermined significance and low-grade intraepithelial lesion cytology results in postmenopausal women. METHODS: All consecutive atypical squamous cells of undetermined significance and low-grade intraepithelial lesion smears in 1-year period were collected and p16/Ki-67 immunostaining was performed retrospectively. The results were compared with histology results or long-term cytology follow-up in cases with no biopsy. RESULTS: The sensitivity of p16/Ki-67 immunostaining for the detection of cervical intraepithelial neoplasia (CIN) 2 and CIN 3 was 57.1% and 85.0%, respectively. The specificity for the detection of CIN 2 was 94.3% and CIN 3 92.4%. Negative predictive values for the detection of CIN 2 and CIN 3 were 96.3% and 99.6%, respectively. CONCLUSIONS: Dual p16/Ki-67 immunostaining is a useful additional method in postmenopausal patients with low-grade cytology. Considering the high specificity and negative predictive value in our study, we believe that it could be helpful in avoiding unnecessary referrals to colposcopy and thus reduce the cost of the program.

[Evaluation the triage performance of p16/Ki-67 dual staining for HR-HPV positive women].

Objective: This study aimed to evaluate the clinical performance of p16/Ki-67 dual staining for triage high risk HPV (HR-HPV) infected women. Method: Target objects were women who infected HR-HPV and received colposcopy examination between April and December of 2016 at the Second Affiliated Hospital of Zhengzhou University. Gynecologists collected the cervical exfoliated cells from eligible women for p16/Ki-67 dual staining, LBC testing and HPV DNA testing. Histology diagnosis were used as gold standard. Sensitivities, specificities, positive predictive values (PPVs), negative predictive values (NPVs) of p16/Ki-67 dual staining, LBC testing and HPV16/18 testing for triage of HR-HPV positive population were calculated and compared. Results: A total of 295 HR-HPV infected women were selected, and the mean age was (44.29±11.48) years old. Positive rates of p16/Ki-67 dual staining, HPV16/18 testing and LBC testing were 70.17% (207), 56.95% (168) and 85.76% (253), respectively. When CIN2+as the endpoint, among the three triage methods, sensitivity of p16/Ki-67 dual staining was 90.00% (95%CI: 85.06%-93.43%), higher than the value of HPV 16/18 testing, but lower than the value of LBC testing. Specificity, PPV and NPV of p16/Ki-67 dual staining were the highest [71.58% (95%CI: 61.81%-79.67%), 86.96% (95%CI:81.69%-90.88%) and 77.27% (95%CI: 67.49%-84.78%)]. When detection for CIN3+, sensitivity of p16/Ki-67 dual staining was 92.90% (95%CI: 87.74%-95.99%), lower than the value of LBC testing, but higher than the value of HPV16/18 testing. Specificity of p16/Ki-67 dual staining was 55.00% (95%CI: 46.74%-63.00%), lower than the value of HPV16/18 testing, but higher than the value of LBC testing. PPV of p16/Ki-67 dual staining was 69.57% (95%CI: 62.99%-75.43%), lower than the value of HPV 16/18 testing, but higher than the value of LBC testing. NPV of p16/Ki-67 dual staining was 87.50% (95%CI: 78.99%-92.87%), higher than value of HPV 16/18 testing, but lower than the value of LBC testing. Conclusion: p16/Ki-67 dual staining has better clinical effects than HPV 16/18 testing and LBC testing for triage women with HR-HPV infection.

Accuracy of grading pancreatic neuroendocrine neoplasms with Ki-67 index in fine-needle aspiration cellblock material.

OBJECTIVE: The aim of this study was to assess the preoperative tumour grade of pancreatic neuroendocrine neoplasms (panNENs) by determining the Ki-67 index in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) material and to correlate the preoperative tumour grade with the postoperative tumour grade in surgical specimens. METHODS: We performed a retrospective review of the institutional pathology database over a 10-year period (2007-2017) to identify all cases of panNENs with corresponding preoperative EUS-FNA cytological material and surgical specimens. Fifteen cases with adequate EUS-FNA material (more than 400 tumour cells on cellblock) were identified. The cytological and histological samples were graded based on the mitotic rate and the Ki-67 index in accordance with the 2017 World Health Organisation grading system for panNENs. The tumour grades determined on EUS-FNA cellblock material were compared with the histological tumour grades. RESULTS: Mean age at diagnosis was 64.8 ± 12.7 years (range, 38-85 years). The grading scores assigned to the cytological and histological samples were concordant in all 15 (100%) cases. Of those, two (13%) cases were scored as grade 1, nine (60%) cases as grade 2 and four (27%) cases as grade 3 tumours. CONCLUSION: Our study shows that tumour grade in patients with PanNENs can be reliably determined by assessing the Ki-67 index in EUS-FNA specimens based on the 2017 World Health Organisation classification and grading system.

Meta-analysis on the performance of p16/Ki-67 dual immunostaining in detecting high-grade cervical intraepithelial neoplasm.

AIM: Although routine screening contributes to substantial reductions in cervical cancer morbidity and mortality, the low specificity of HPV detection and limited sensitivity of cervical cytology necessitates the application of more optimized markers, such as the newly-introduced p16/Ki-67 dual-staining method. Here we reviewed several studies to evaluate the performance of this method in cervical cancer screening. METHODS: An electronic database search was performed on PubMed, Web of Science, CNKI and Wanfang Database for studies assessing p16/Ki-67 dual immunostaining in the diagnosis of high-grade cervical intraepithelial neoplasm (HGCIN) with abnormal cytological morphologies. Two reviewers screened literatures, extracted data and assessed the quality of the included studies independently. Meta-analysis was performed using ReV. Man 5.2 and Meta-DiSc 1.2 software packages. RESULTS: The absolute sensitivity of p16/Ki-67 dual staining for diagnosing HGCIN ranged from 80% to 94%, while the sensitivity of triage method with hrHPV testing ranged from 78% to 96%. The specificity of p16/Ki-67 testing and hrHPV detection for predicting absence of CIN2+ ranged from 39% to 79% and 15% to 44%, respectively. Quantitative meta-analysis showed that the pooled sensitivity of p16/ki-67 dual staining is 0.88 [95'CI (0.86-0.90)], the pooled specificity is 0.58 [95'CI (0.56-0.60)]. For hrHPV testing, the pooled sensitivity and pooled specificity is 0.94 [95'CI (0.93-0.96)] and 0.32 [95'CI (0.29-0.34)], respectively. CONCLUSIONS: p16/Ki-67 dual immunostaining had comparable sensitivity and improved specificity in screening HGCIN or CC when compared with hrHPV detection. Further studies may be beneficial to assess the efficacy of this novel biomarker, which can be potentially used as one of the initial screening assays.

Immunocytochemical staining for p53 and Ki-67 helps to characterise urothelial cells in urine cytology.

OBJECTIVE: The presence of atypical cells in urine cytology is unsatisfactory for both cytologists and clinicians. The objective of this study was to test whether p53 and Ki-67 immunostaining could improve urothelial carcinoma (UC) detection on urinary cytology. METHODS: A total of 196 urine samples were analysed, 142 from the bladder, 41 from the upper tract and 13 from ileal bladder replacement. Cytology results were expressed as normal (N) (n = 81), atypia cannot exclude low-grade UC (ALG) (n = 25), suspicious for high-grade UC (SHG) (n = 39) and high-grade UC (HG) (n = 51). Actual diagnoses were confirmed by histopathological analysis, cystoscopic examination or follow-up for at least 1 year. Immunocytochemistry performed on CytoSpin™ slides allowed the determination of the percentage of positive cells with p53 and Ki-67. RESULTS: The median percentage values [first to third quartile] of p53 and Ki-67 were 0 [0-5] and 0 [0-1] for N cytology, 5 [0-40] and 2 [1-10] for ALG, 10 [0-30] and 6 [3-25] for SHG, and 30 [10-80] and 20 [10-30] for HG, respectively. Statistically higher values were observed for both tests (P < 0.001) in positive cytologies (ALG, SHG and HG). The optimal cut-offs were 5% for p53 and 3% for Ki-67. The sensitivity and specificity for the detection of all UC were 86.4% and 76.7% for cytology alone, 81.3% and 93.2% for cytology and p53, 75.7% and 88% for cytology and Ki-67, and 68.9% and 97.5% for cytology, p53 and Ki-67, respectively. CONCLUSION: Using p53 and/or Ki-67 in addition to cytology increases the specificity without penalising the sensitivity.

HPV16 genotype, p16/Ki-67 dual staining and koilocytic morphology as potential predictors of the clinical outcome for cervical low-grade squamous intraepithelial lesions.

OBJECTIVE: To evaluate the association of human papillomavirus (HPV) 16 and non-16 genotype, p16/Ki-67 dual staining and koilocytosis and their role in the prediction of the clinical outcome of low-grade squamous intraepithelial lesion (LSIL) cytology. METHODS: One hundred and fifty-five patients with LSIL were followed up and recorded as progression, persistence or regression. HPV genotyping was performed for high-risk HPV (hrHPV) DNA-positive cases. Koilocytosis was reviewed and p16/Ki-67 dual staining was performed on reprocessed conventional cytology slides. RESULTS: HPV16 was the most frequent genotype found in 16.3% of cases. p16/Ki-67 dual staining was positive in 36.1% of all cases. Progression, including concurrent cervical intraepithelial lesion grade 2 or above (CIN2+), was recorded in 13.8% of cases. A statistically significant difference between progressive and non-progressive cases was shown by the following: hrHPV-positive versus hrHPV-negative (P = 0.022), HPV16-positive versus non-16 HPV-positive (P < 0.001) and p16/Ki-67-positive versus p16/Ki-67-negative (P < 0.001) cases. Cases with combined HPV16 and p16/Ki-67 positivity showed the highest progression rate (58.3%). Non-koilocytic HPV16-positive cases showed a 50% progression rate compared with 10.1% for koilocytic non-16 HPV-positive cases (P = 0.010). The sensitivity of p16/Ki-67 dual staining for the detection of CIN2+ lesions was 80%, comparable with hrHPV (85%). The specificity of p16/Ki-67 dual staining was 71% and of hrHPV 42%. The highest specificity was found for HPV16 genotype presence (91%), but with low sensitivity (50%). CONCLUSION: HPV genotyping, p16/Ki-67 dual staining and koilocytic morphology can be useful in the prediction of clinical outcome in women initially diagnosed with LSIL cytology.

Aggressive pituitary lesion with a remarkably high Ki-67.

The uncommon aggressive pituitary tumors are named carcinomas when metastases are detected, either in the central nervous system and/or systemically. Some cases are associated with hormonal overproduction, but most are diagnosed because of local symptoms. These neoplasias are generally refractory to current treatments. A 51 year-old woman presented sudden onset of headache, left arm paresis and left facial hypoesthesia. Computed tomography scan and magnetic resonance imaging revealed a pituitary tumor invading the left sphenoidal and cavernous sinuses. Laboratory data excluded hormonal hypersecretion. The patient underwent transsphenoidal surgery and histological findings showed a neoplasia with Ki-67 estimated at 75%. Medical imaging excluded both a primary occult tumor and central nervous system or systemic dissemination. Three weeks postoperatively, neurological condition worsened, with new onset of ataxia, bilateral ptosis, ophthalmoplegia and an increase in the size of the lesion, leading to surgical intervention by craniotomy, followed by only a few sessions of radiotherapy, because of severe disease progression. Patient died nearly 2 months after the initial manifestations. This case illustrates the aggressiveness of some pituitary lesions, the limited efficacy of current treatment modalities such as surgery or radiotherapy and the pitfalls of the current pituitary tumors classification. To our knowledge, this case corresponds to one of the most aggressive pituitary neoplasms reported so far, with a very high Ki-67 index (75%) and short survival (2 months). Ki-67 index could be of prognostic value in pituitary tumors. Pituitary tumors World Health Organization (WHO) classification could be revisited.

Improvement of the cytological diagnostic accuracy of follicular thyroid lesions by the use of the Ki-67 proliferative index in addition to cytokeratin-19 and HBME-1 immunomarkers: a study of 61 cases of liquid-based FNA cytology with histological controls.

OBJECTIVES: To evaluate HBME-1, cytokeratin-19 (CK-19) and Ki-67 immunomarkers in order to increase the diagnostic accuracy of preoperative thyroid fine needle aspiration (FNA) cytology. METHODS: Immunocytochemistry against HBME-1, CK-19 and Ki-67 was performed on 123 thyroid FNAs processed by liquid-based cytology (LBC). Statistical analysis was carried out on 61 cases with histological control and sufficient material for one or more of the three markers. The Bethesda System was used for cytological diagnosis. RESULTS: Taking into account all the cytological categories, with a cut-off of 30% of positive cells, HBME-1 (n = 47) and CK-19 (n = 53) showed a sensitivity for malignancy of 66.7% (95% confidence interval, 53.2-80.1) and 90.5% (82.6-98.4) and a specificity of 90.6% (82.3-99) and 75% (63.3-86.7), respectively. For Ki-67 (n = 54) with a cut-off of 1% of positive cells, the sensitivity was 85.0% (75.5-94.5) and the specificity 70.6% (58.4-82.7). In the follicular neoplasm/suspicious for follicular neoplasm (FN/SFN) category (n = 37), which was the focus of the study, papillary thyroid carcinomas (PTCs) were less numerous (four cases, three of which were the follicular variant), the positivity of the three immunomarkers combined showed an overall accuracy of 91% (21/23). The mean percentage of Ki-67-positive cells was increased in malignant lesions, with the exception of follicular variant PTCs: 16% ± 15.6% in two follicular carcinomas, 4.8% ± 3.2% in 13 classical PTCs, 1% ± 1.2% in five follicular variant PTCs and 0.5% ± 1.9% in 34 non-malignant lesions. CONCLUSIONS: Immunocytochemistry using HBME-1, CK-19 and the Ki-67 proliferative index increased the diagnostic accuracy of FNA in the FN/SFN category of the Bethesda System, which may help to distinguish lesions in this category with a low or high risk of malignancy. Thus, clinical management would be improved.

Chromogenic in situ hybridization and p16/Ki67 dual staining on formalin-fixed paraffin-embedded cervical specimens: correlation with HPV-DNA test, E6/E7 mRNA test, and potential clinical applications.

Although HPV-DNA test and E6/E7 mRNA analyses remain the current standard for the confirmation of human papillomavirus (HPV) infections in cytological specimens, no universally adopted techniques exist for the detection of HPV in formalin-fixed paraffin-embedded samples. Particularly, in routine laboratories, molecular assays are still time-consuming and would require a high level of expertise. In this study, we investigated the possible use of a novel HPV tyramide-based chromogenic in situ hybridization (CISH) technology to locate HPV on tissue specimens. Then, we evaluate the potential usefulness of p16(INK4a)/Ki-67 double stain on histological samples, to identify cervical cells expressing HPV E6/E7 oncogenes. In our series, CISH showed a clear signal in 95.2% of the specimens and reached a sensitivity of 86.5%. CISH positivity always matched with HPV-DNA positivity, while 100% of cases with punctated signal joined with cervical intraepithelial neoplasia grade 2 or worse (CIN2+). p16/Ki67 immunohistochemistry gave an interpretable result in 100% of the cases. The use of dual stain significantly increased the agreement between pathologists, which reached 100%. Concordance between dual stain and E6/E7 mRNA test was 89%. In our series, both CISH and p16(INK4a)/Ki67 dual stain demonstrated high grade of performances. In particular, CISH would help to distinguish episomal from integrated HPV, in order to allow conclusions regarding the prognosis of the lesion, while p16(INK4a)/Ki67 dual stain approach would confer a high level of standardization to the diagnostic procedure.

Immunostaining of p16(INK4a)/Ki-67 and L1 capsid protein on liquid-based cytology specimens obtained from ASC-H and LSIL-H cases.

BACKGROUND: Atypical squamous cell cannot exclude high-grade squamous intraepithelial lesion (ASC-H) and low-grade intraepithelial lesion cannot exclude high-grade squamous intraepithelial lesion (LSIL-H) are ambiguous diagnostic entities for the prediction of high-grade cervical lesion. Objective and reproducible tests for predicting high-grade cervical lesions are needed to reduce unnecessary colposcopic referrals or follow-ups. OBJECTIVE: We aimed to identify an adequate set of adjunctive markers to predict cervical intraepithelial neoplasia grade 2+ (CIN2+) in residual liquid-based cytology specimens (LBCS). METHODS: We conducted p16 (INK4a)/Ki-67 and L1 capsid protein immunostaining and human papillomavirus (HPV) DNA typing on 56 LBCS diagnosed with ASC-H or LSIL-H, all of which were subjected to histologic confirmation or follow-up cytologic examination. RESULTS: Positivity for p16 (INK4a)/Ki-67 was associated with a histology of CIN2+ (P=0.047) and CIN3+ (P=0.002). Negativity for L1 capsid protein was associated with CIN2+ confirmed at follow-up (P=0.02).Positivity for high-risk HPV (HR-HPV) was associated with CIN2+ confirmed at follow-up (P=0.036) and a histology of CIN2+ (P=0.037). The sensitivity, specificity, positive predictive value, and negative predictive value for predicting follow-up CIN2+ were 76.2%, 51.4%, 48.5%, and 78.3%, respectively, for p16 (INK4a)/Ki-67 immunostaining; 95.2%, 34.3%, 46.5%, and 92.3%, respectively, for L1 capsid protein; and 66.7%, 67.7%, 54.5%, and 77.8%, respectively, for HR-HPV. The classification and regression tree analysis showed that the combined results of p16 (INK4a)/Ki-67 andL1 capsid protein immunostaining and the HR-HPV test, conducted sequentially, correctly classified 81.8% of samples (27/33)in the prediction of a histology of CIN2 + in ASC-H or LSIL-H. For determination of the histology of cervical intraepithelial neoplasia grade 3+ (CIN3+)in ASC-H or LSIL-H, we found that the combined results of p16 (INK4a)/Ki-67 and L1 capsid protein immunostaining correctly classified 78.8% (26/33) of samples. CONCLUSIONS: p16(INK4a)/Ki-67 and L1 capsid protein immunostaining and HR-HPV testing of residual LBCS diagnosed with ASC-H or LSIL-H are useful objective biomarkers for predicting CIN2+. Immunostaining for p16(INK4a)/Ki-67 and L1 capsid protein are sufficient to predict CIN3+.

[Ki-67 -- new faces of an old player]. / Ki-67 -- egy régi játékos új arcai.

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.

Low-fat, high fruit and vegetable diets and weight loss do not affect biomarkers of cellular proliferation in Barrett esophagus.

Risk factors for esophageal adenocarcinoma include obesity, high fat intake, and low consumption of fruits and vegetables. This trial tested whether an intervention to reduce these risk factors in patients with Barrett esophagus, a preneoplastic condition for esophageal adenocarcinoma, could reduce biomarkers of cellular proliferation and, by inference, the risk of neoplastic progression. Eighty-seven men and women with Barrett esophagus were randomized to an intensive dietary intervention or control group. At baseline, 18 and 36 months after intervention, biopsies were obtained at 2-cm intervals throughout the length of the Barrett segment. Ki67/DNA content flow cytometry was used to assess (a) % Ki67-positive proliferating diploid G(1) cells, (b) % total Ki67-positive proliferating cells, (c) presence of aneuploidy, and (d) presence of >6% of cells in the 4N (G(2)/tetraploid) fraction of the cell cycle. We also assessed re-epithelialization and length of the Barrett segment, reflux symptoms, and medication use. The intervention effects for energy, fat, fruits and vegetables, and weight were, respectively, -314 kcal, -12.2% energy, 1.8 servings/d, and -4.0 kg at 18 months (all P < 0.005) and were smaller but remained significant at 36 months. There were no significant effects of the intervention on any biomarker of cellular proliferation. The intervention effects +/- SE for mean %G(1) Ki67+ cells were 0.98 +/- 1.58 at 18 months and 1.79 +/- 1.31 at 36 months; the relative risks (95% confidence interval) for developing >6% of cells in 4N were 0.5 (0.1-2.6) at 18 months and 0.75 (0.2-3.1) at 36 months. A single control participant developed aneuploidy. There were no significant effects on re-epithelialization, segment length, or reflux medication use. We conclude that substantial dietary change has no short-term effects on biomarkers of cellular proliferation in Barrett esophagus or on clinical observations of the Barrrett segment.

Ki-67 expression in benign breast ductal cells obtained by random periareolar fine needle aspiration.

Ki-67 expression in ductal cells obtained by random periareolar fine needle aspiration (RPFNA) is currently being used as a response biomarker in phase II breast cancer chemoprevention trials; however, Ki-67 in RPFNA has not been well studied as a risk predictor for cancer, which would support its use as a response indicator. We examined the expression of Ki-67 in RPFNA specimens with hyperplasia +/- atypia obtained from 147 women at high risk for development of breast cancer. Median Ki-67 was 1.4% (range 0-24%). Ki-67 was higher in specimens from women < 50 versus those > or = 50 (median 2% versus 0.6%; P = 0.006) and from premenopausal women versus postmenopausal women (P = 0.037); however, hormone replacement therapy (predominately low-dose estrogen without progestins) had no effect. By univariate analysis, Ki-67 was positively correlated with ductal cell number (P = 0.001) and hyperplasia with atypia (P = 0.007). By multivariable analysis, the proportion of ductal cells expressing Ki-67 was again predicted by cell number, which, in turn, was predicted by cytologic atypia. The association of Ki-67 expression with cytologic atypia, a known risk factor for development of breast cancer, provides preliminary justification for its use as a response biomarker in phase II chemoprevention trials.

Serum p53 antibodies in correlation to other biological parameters of breast cancer.

Breast cancer is the second most frequent cancer of Thai women. Mutation of p53 is a common event in breast cancer. This alteration can result in cellular accumulation of p53 and may also found in serum p53 antibodies (p53-Abs). To clarify prognostic significance of these antibodies, we evaluated p53-Abs in 158 sera of patients with breast cancer. Thirty (19%) patients were found to have p53-Abs. The incidence of p53-Abs tended to be higher in patients with advanced disease group (stages III and IV) than patients with early disease group (stages I and II) (P=0.055). Strong correlations were found between the presence of p53-Abs and p53 protein expression (P<0.001) and lymph node status (P=0.021). The presence of p53-Abs was associated with lack of estrogen (ER) receptor expression (P=0.035) but was not related to progesterone receptor (PR) (P=0.567). In addition, there was a statistically significant correlation between p53-Abs and proliferation associated antigen Ki-67 (P=0.006), but no relation between c-erbB2 oncoprotein and p53-Abs was observed (P=0.112). Additionally, no correlation was noted between the presence of p53-Abs and serum carcinoembryonic antigen (CEA) or carbohydrate antigen (CA15-3). Our findings indicate that p53-Abs appears to be a promising new parameter to evaluate the cellular biology and prognosis of breast cancer.

Immunohistochemical localization and comparison of carboxypeptidases D, E, and Z, alpha-MSH, ACTH, and MIB-1 between human anterior and corticotroph cell "basophil invasion" of the posterior pituitary.

Basophil invasion, i.e., invasion of basophilic corticotrophs from the residual intermediate lobe into the posterior lobe of the human pituitary gland, is believed to be a physiological phenomenon. This study evaluated the distribution of CPE, CPD, CPZ, alpha-MSH, ACTH, and Ki-67 immunoreactivity between human anterior pituitary and basophil invasion of the neurohypophysis. Mild to moderate immunoreactivities for CPE and CPZ were distributed relatively uniformly in the majority of the anterior pituitary cells and basophil invasion. In contrast, only corticotrophs exhibited intense CPD immunoreactivity. Basophil invasion showed similar immunoreactivities for alpha-MSH, ACTH, CPE, and CPZ as corticotrophs in the anterior pituitary, except for CPD, which was detected much less frequently. In the posterior lobe, CPE, CPD, and CPZ were present within the Herring bodies. Although no MIB-1 immunoreactivity was identified in anterior pituitary cells, limited MIB-1 labeling was detected in basophil invasion in five of ten cases. Highly selective expression of CPD in corticotrophs suggests that CPD plays a particularly important role in prohormone (POMC) processing in corticotrophs, with minimal or no significant roles in non-corticotrophs. Evidence that corticotrophs in basophil invasion are undergoing proliferation and are also phenotypically different from their counterpart in the anterior pituitary has further raised the possibility of some neoplastic potential.

The dominant source of CD4+ and CD8+ T-cell activation in HIV infection is antigenic stimulation.

To distinguish between antigenic stimulation and CD4+ T-cell homeostasis as the cause of T-cell hyperactivation in HIV infection, we studied T-cell activation in 47 patients before and during highly active antiretroviral therapy (HAART). We show that expression of human leukocyte antigen (HLA)-DR, CD38, and Ki67 on T cells decreased during HAART but remained elevated over normal values until week 48 of therapy. We confirm previous reports that T-cell activation correlates positively with plasma HIV RNA levels (suggesting antigenic stimulation), and negatively with CD4 count (suggesting CD4+ T-cell homeostasis). However, these correlations may be spurious, because misleading, due to the well-established negative correlation between CD4 count and plasma HIV RNA levels. To resolve this conflict, we computed partial correlation coefficients. Correcting for CD4 counts, we show that plasma HIV RNA levels contributed to T-cell hyperactivation. Correcting for plasma HIV RNA levels, we show that CD4+ T-cell depletion contributed to T-cell activation. Correcting for both, activation of CD4+ and CD8+ T cells remained positively correlated. Because this suggests that CD4+ and CD8+ T-cell activation is caused by a common additional factor, we conclude that antigenic stimulation by HIV or other (opportunistic) infections is the most parsimonious explanation for T-cell activation in HIV infection. Persistence of HIV antigens may explain why T-cell activation fails to revert to levels found in healthy individuals after 48 weeks of therapy.

Ki-67 reactivity in primary fallopian tube cancers.

Forty-four cases of primary cancer of the fallopian tube (PFTC) were analyzed as to Ki-67 expression, grade, stage and the cancer histological type. Among patients with an average age of 57.5 years (range 38-70 years), 27 patients were FIGO I, 7 were FIGO II and 10 were FIGO III. Histological classification of PFTC revealed 18 cases of endometrioid type, 9 serous, 7 undifferentiated, 6 urothelial, 2 clear-cell and 2 of other type. Histological grading revealed 11 cases of G1, 16 of G2 and 17 of G3 tumors. The quantity of Ki-67 positive cells was counted on 300 cancer cells in random high-power fields (10 x 40) and recorded as the labeling index (LI, %). Positive staining for Ki-67 was shown in the nuclei in all cases. Ki-67 LI values ranged from 14.2 to 97.2% (median 36.1). Ki-67 LI values were graded as > or = 36.1% as high and <36.1% as low. We did not find any significant differences in Ki-67 LI values among tumors of various clinical stages, histological grades and histological types. The p value was statistically significant only for stage as a prognostic factor.

The proliferation-specific human Ki-67 protein is a constituent of compact chromatin.

The human nuclear Ki-67 protein (Ki-67p) is expressed in proliferating, but not in quiescent, cells and is therefore widely used as a proliferation marker in histopathological research and practice. However, information regarding its intranuclear location is scarce and controversial. Here we describe the results of cell fractionation and nuclease digestion experiments using nuclei isolated from human HeLa cells in interphase. Ki-67p dissociates at 0.3-0.4 M NaCl from its nuclear binding sites, and gradient centrifugations indicate that the released Ki-67p is most likely a single molecular entity and not complexed to other proteins. In nuclei, prepared under physiological salt conditions, the binding sites are largely resistant against micrococcal nuclease. However, when prepared at very low ionic strengths, chromatin regions with associated Ki-67p become accessible to micococcal-nuclease-producing chromatin fragments that carry bound Ki-67p. We conclude that Ki-67p is a chromatin protein and resides at densely packed regions, probably heterochromatin. Our data provide a useful basis for further biochemical research on this human nuclear protein.

Biomarkers of human colonic cell growth are influenced differently by a history of colonic neoplasia and the consumption of acarbose.

The nutritional effects of butyrate on the colonic mucosa and studies of transformed cells suggest that butyrate has anti-colon cancer effects. If butyrate has antineoplastic effects, mucosal growth contrasts between normal subjects and those with a history of colonic neoplasia would parallel changes in growth characteristics caused by butyrate in a colon neoplasia population. To test this hypothesis, rectal biopsies from a survey of colonoscopy patients (n = 50) with and without a history of colonic neoplasia (controls) were compared. Similarly, rectal biopsies were compared from subjects (n = 44) with a colon neoplasia history in an acarbose-placebo crossover trial. Control subjects in the colonoscopy survey had higher bromodeoxyuridine (BrdU) uptake than subjects with a history of neoplasia (P = 0.05). The control subjects also had a higher correlation of BrdU and Ki-67 labeling (P = 0.003). Both findings were paralleled by acarbose use. Acarbose augmented BrdU uptake (P = 0.0001) and improved the correlation of BrdU and Ki-67 labeling (P = 0.013). Acarbose also augmented fecal butyrate (P = 0.0001), which was positively correlated with Ki-67 labeling (P = 0.003). p52 antigen had an earlier pattern of crypt distribution in subjects with a history of colon neoplasia but was not affected by acarbose use. Lewis-Y antigen was expressed earlier in the crypt with acarbose but had similar expression in the colonoscopy survey groups. The use of acarbose to enhance fecal butyrate concentration produced mucosal changes paralleling the findings in control subjects as opposed to those with neoplasia, supporting the concept of an antineoplastic role for butyrate.

The biochemical characterization of the DNA binding activity of pKi67.

Ki67 is only expressed in the nucleus of cycling cells. While it is employed as an operational marker of proliferation, little is known of the biochemical properties of this large protein. Using an immunoaffinity strategy for purification of pKi67, this study has shown that it can form higher-order complexes and can bind to DNA cellulose in vitro. No other co-purifying proteins could be identified, strongly suggesting that the DNA binding activity is an inherent property of pKi67. Using an electromobility shift assay, the affinity of pKi67 was shown using a range of different forms of DNA as competitors. Single-stranded DNA was the poorest competitor, followed by double-stranded DNA, with supercoiled DNA being the best competitor. In addition, it was found that purified pKi67 has a preference for AT-rich DNA. The DNA binding domain is mapped to the C-terminal domain of pKi67, and recombinant protein from the terminal 321 residues of pKi67 can bind DNA in vitro. GFP constructs from this domain were used to map regions that could target nucleolar localization and allow DNA binding. Finally, it was found that over-expression of the C-terminal 321 residues in cells induced chromatin disruption and apoptosis. These data provide strong evidence that pKi67 has a novel DNA binding activity within the C-terminal domain and that this protein can influence chromatin structure.