Immunogold labelling of PCNA and Ki-67 antigen at the ultrastructural level in laryngeal squamous cell carcinoma and its correlation with lymph node metastasis and histological grade

The effects of proliferating cell nuclear antigen and p53 in patients with oral squamous cell carcinoma: a systematic review and meta-analysis

BACKGROUND

To evaluate the effect of proliferating cell nuclear antigen (PCNA) and p53 in patients with oral squamous cell carcinoma (OSCC).

METHODS

Multiple databases, including PubMed, Embase, Cochrane library, and China National Knowledge Database, were searched for relevant studies and full-text articles that evaluated the effect of PCNA and p53 in patients with OSCC. Review Manager 5.2 was adopted to estimate the impact of the results among the selected articles. Forest plots, NOS table, sensitivity analysis, and bias analysis were also conducted.

RESULTS

In total, nine eligible studies satisfied the included criteria. High PCNA expression (>50%) was significantly more prevalent in OSCC than low PCNA expression (<50%) (OR =3.88; 95% CI: 2.04-7.37; P<0.0001; I²=0%). However, there was no significant difference between p53 and OSCC (OR =1.60; 95% CI: 0.18-14.63; P=0.68; I²=86%). Low PCNA expression had a higher 5-year overall survival in OSCC patients than high PCNA expression (OR =0.47; 95% CI: 0.27-0.80; P=0.005; I²=41%). Meanwhile, p53 negative had a higher 5-year overall survival than p53 positive (OR =0.20; 95% CI: 0.10-0.42; P<0.0001; I²=0%). There was no difference between high and low PCNA in terms of metastasis (OR =0.80 with 95% CI: 0.18-3.45, I²=63%, P of over effect =0.76). The overall results showed no difference between p53 and metastasis (OR =0.38 with 95% CI: 0.13-1.10, I²=0%, P of over effect =0.07).

DISCUSSION

PCNA and p53 might be suitable for prognostic and survival evaluation in OSCC patients.

CD73 Promotes Glioblastoma Pathogenesis and Enhances Its Chemoresistance via A2B Adenosine Receptor Signaling

Glioblastoma (GB) is one of the deadliest brain cancers to afflict humans, and it has a very poor survival rate even with treatment. The extracellular adenosine-generating enzyme CD73 is involved in many cellular functions that can be usurped by tumors, including cell adhesion, proliferation, invasion, and angiogenesis. We set out to determine the role of CD73 in GB pathogenesis. To do this, we established a unique GB mouse model (CD73-FLK) in which we spatially expressed CD73 on endothelial cells in CD73^-/- mice. This allowed us to elucidate the mechanism of host CD73 versus GB-expressed CD73 by comparing GB pathogenesis in WT, CD73^-/-, and CD73-FLK mice. GB in CD73^-/- mice had decreased tumor size, decreased tumor vessel density, and reduced tumor invasiveness compared with GB in WT mice. Interestingly, GBs in CD73-FLK mice were much more invasive and caused complete distortion of the brain morphology. We showed a 20-fold upregulation of A_2B AR on GB compared with sham, and its activation induced matrix metalloproteinase-2, which enhanced GB pathogenesis. Inhibition of A_2B AR signaling decreased multidrug resistance transporter protein expression, including permeability glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1). Further, we showed that blockade of A_2B AR signaling potently increased GB cell death induced by the chemotherapeutic drug temozolomide. Together, these findings suggest that CD73 and A_2B AR play a multifaceted role in GB pathogenesis and progression and that targeting the CD73-A_2B AR axis can benefit GB patients and inform new approaches for therapy to treat GB patients.SIGNIFICANCE STATEMENT Glioblastoma (GB) is the most devastating primary brain tumor. GB patients' median survival is 16 months even with treatment. It is critical that we develop prophylaxes to advance GB treatment and improve patient survival. CD73-generated adenosine has been implicated in cancer pathogenesis, but its role in GB was not ascertained. Here, we demonstrated that host CD73 plays a prominent role in multiple areas of glioblastoma pathogenesis, including promoting GB growth, its angiogenesis, and its invasiveness. We found a 20-fold increase in A_2B adenosine receptor (AR) expression on GB compared with sham, and its inhibition increased GB chemosensitivity to temozolomide. These findings strongly indicate that blockade or inhibition of CD73 and the A_2B AR are prime targets for future GB therapy.

Immunoelectron microscope localization of androgen receptors and proliferating cell nuclear antigen in the epithelial cells of albino rat ventral prostate

Androgen receptor (AR) and proliferating cell nuclear antigen (PCNA) play a crucial role in development and progression of various prostatic diseases including prostatic carcinoma that is a leading cause of death in males. Previous studies have evaluated the expression pattern of AR and PCNA in prostate epithelial cells using immunohistochemistry (IHC). However, this technique has limited ability to identify their precise subcellular localization. Therefore, the aim of this study was to localize, subcellularly, AR and PCNA in the secretory epithelial cells of rat ventral prostate using post embedding immunogold-electron microscopy. The ventral lobes were dissected from six adult male albino rats after being perfused with paraformaldehyde. Some specimens were immuno-labeled with AR or PCNA and others were processed for immuno-electron microscope of AR and PCNA using 15-nm gold conjugated secondary antibodies. The results showed that, by immunoperoxidase reaction, AR and PCNA were localized diffusely throughout the nuclei of the epithelial cells of prostatic acini without visible cytoplasmic expression. However, the higher resolution immuno-electron microscopy was able to detect AR and PCNA in the nucleus and some cytoplasmic organelles. In conclusion, this study emphasizes the importance of immuno-electron microscopy in precise localization of AR and PCNA at the subcelullar levels in the secretory epithelial cells of the rat prostatic acini. These findings will help to further understand the mechanism of action of these receptors under normal and pathological conditions that could have future clinical application after careful human investigation.

p63 and Ki-67 immunostainings in laryngeal squamous cell carcinoma are related to survival

To examine the prognostic significance of the immunohistochemical expression of p63 and Ki-67 oncoproteins in patients with laryngeal squamous cell carcinoma, a retrospective evaluation was carried out on a cohort of 108 patients with primary laryngeal squamous cell carcinoma (LSCC) treated by primary surgery. For the immunohistochemical evaluation, tissue section obtained by formalin-fixed and paraffin-embedded tissue blocks from resection of each patient was used. Clinicopathologic data were associated with the immunostaining results. The association among the considered variables was assessed by Fisher's exact test, Mann-Whitney test, non-parametric χ(2) test, and Spearman's rho rank test was used to assess the relations among them. Differences in p63 and Ki-67 immunoreactivity among the different groups were compared via Kruskal-Wallis test and post hoc tests were performed using Mann-Whitney test with Bonferroni correction. The overall survival rate was estimated via Kaplan-Meier method, and the cumulative incidence functions for different groups were compared using log-rank statistics. Cox proportional hazard model was employed in a multivariate analysis to assess the effect of prognostic factors in the overall survival rate. Furthermore, taking into account death due to other causes, we estimated LSCC-related survival and disease-free survival rates using competing risk analysis. The results of immunohistochemical examination showed a statistically significant relationship between the up-regulation of P63 and Ki-67, an increase in histological grading, and primary tumours associated with lymph node metastases. p63 and Ki-67 up-regulation was related to a shorter disease-free survival and a significant association was found between p63 and Ki-67 percentage of positive cells and patient survival. Finally, we noticed a significant relation between p63 and Ki-67 (ρ = 0.87). On the other hand, no statistically significant associations were found between p63 and Ki-67 down-regulation and clinicopathologic data. Our findings suggest that abnormal p63 and Ki-67 immunoreactivity may be involved in the early phases of laryngeal tumorigenesis and may become a significant prognostic predictor for both overall and disease-free survivals. These biomarkers could thus help in the selection of high-risk patients with LSCC who may benefit from more aggressive therapy or chemoprevention.

Preliminary results of prognostic significance of proliferating cell nuclear antigen expression in advanced primary larynx carcinomas and lymph node metastases

INTRODUCTION

The aim of this study was to investigate the prognostic significance of proliferating cell nuclear antigen (PCNA) expression in laryngeal carcinoma in relation to clinicopathological features. Special emphasis was placed on examining the relationship of PCNA expression in the primary tumour and PCNA expression in corresponding lymph node metastases obtained from the same patients.

MATERIAL AND METHODS

The study included 60 patients with advanced larynx carcinoma who had received treatment and follow-up for at least 5 years. Sixty laryngeal carcinoma specimens and metastatic lymph nodes from 24 patients were examined for immunohistochemical PCNA expression.

RESULTS

The percentages of PCNA positive cells were significantly higher in the primary tumours which developed lymph node metastases than in those without metastases. The fraction of PCNA immunolabelled cells in metastatic lymph nodes increased significantly when compared with the PCNA positive cell score in their corresponding primary tumours obtained from the same patient. There was a significant difference in PCNA index score in primary tumours between the group of patients who survived a 5-year period and those who died within 5 years after treatment.

CONCLUSIONS

Our data demonstrate that a high proliferation index in primary larynx tumours is retained and increased in corresponding lymph node metastases. Measurement of the fraction of cancer cells stained for PCNA in primary larynx carcinomas can be helpful in selecting tumours with high aggressiveness potential that are more likely to develop neck metastases and thereby in identifying patients who need elective lymph node dissection or additional treatment.

Assessment of proliferative activity by AgNOR and PCNA in prostatic tissues of ram lambs implanted with zeranol

The aim of this study was to assess cellular proliferation using silver-stained nucleolar organizer regions (AgNOR) and the proliferating cell nuclear antigen (PCNA) in various tissues in the prostate of ram lambs implanted with increasing zeranol doses and to compare the sensitivity of different tissues of lamb prostate to zeranol. Twenty-four Akkaraman lambs were implanted with increasing zeranol doses, including 12 mg (n = 8), 24 mg (n = 8) and 96 mg (n = 8), with eight lambs serving as controls. After 33 days, the prostate tissues of the lambs were stained using AgNOR and PCNA techniques. The prostate tissues were divided into two compartments--the epithelial tissues, including glandular acinus, collecting duct and penile urethra, and the non-epithelial tissues, including interstitial tissue and striated muscle. AgNOR dots and PCNA index on each prostatic tissue were counted under a light microscope and were evaluated statistically. AgNOR staining in the treatment groups showed a higher score in the non-epithelial tissues than the epithelial components, whereas the PCNA index was significant in the epithelial tissues and non-epithelial tissues had very low PCNA immunostaining. According to the PCNA index, collecting duct epithelium showed more sensitivity to increasing zeranol doses and according to AgNOR counts, there was no difference of sensitivity to zeranol among tissues of the same origin. Both AgNOR counts and PCNA indexes seem to be valuable proliferating markers for the epithelial components of ram prostate, but PCNA index had no significance in relation to the non-epithelial components in contrast to AgNOR counts. Therefore, the controversial results arising from the combined use of both techniques as proliferating markers for the ram prostate should be considered in further studies.

The epidemiology of laryngeal cancer in Brazil

The city of São Paulo exhibits one of the highest incidences of laryngeal cancer in world and Brazil presents remarkable occurrence, compared with other Latin American countries. Around 8,000 new cases and 3,000 deaths by laryngeal cancer occur annually in the Brazilian population. In the city of São Paulo, incidence rates for laryngeal cancer among males have been decreasing since the late 1980s while, among females, the rates have shown a stable trend. This phenomenon is probably the expression of changes in gender behavior related to tobacco smoking. Several risk factors are involved in the genesis of laryngeal cancer. The most important are tobacco smoking and alcohol intake, but occupational hazards have also been associated with the disease, such as asbestos, strong inorganic acids, cement dust and free crystalline silica. Additionally, salted meat and total fat intake have been linked to elevated risk of laryngeal cancer. Conversely, several studies have confirmed that fruits, raw leaf vegetables and legumes protect against this cancer. Some researchers have postulated a possible association between laryngeal squamous cell carcinoma and human papilloma virus (HPV), but this is not universally accepted. Gastroesophageal reflux disease is weakly, but consistently correlated with laryngeal cancer. Familial cancer clusters, particularly of head and neck tumors, seem to increase the risk of laryngeal cancer. Some genetic polymorphisms, such as of genes that code for xenobiotic-metabolizing enzymes, have shown elevated risk for laryngeal cancer according to recent studies. Public health policies regarding the control of tobacco smoking and alcohol consumption, and also surveillance of carcinogen exposure in occupational settings, could have an impact on laryngeal cancer. No proposals for screening have been recommended for laryngeal cancer, but one diagnostic goal should be to avoid treatment delay when suspected symptoms have been observed.

Prognostic significance of Ki-67 expression for patients with laryngeal squamous cell carcinoma primarily treated by total laryngectomy

The aim of this study was to determine the prognostic value of Ki-67 immunostaining in laryngeal squamous cell carcinomas. Ki-67 labeling was quantified in 63 laryngeal squamous cell carcinomas by counting at least 1,000 tumor cells in the most immunoreactive area in each sample, and the Ki-67 labeling index was calculated as a percentage. The antigen expression was compared with clinical factors, histopathological grading and prognosis. The Ki-67 mean proliferation index for all patients was 25.44% ( range, 2-75%). A significant correlation was found between Ki-67 mean proliferation index and patient age ( P<0.05), T-stage ( P<0.05), nodal metastasis ( P=0.001) and recurrence ( P<0.001). There was no significant association between the Ki-67 mean proliferation index and tumor site or histologic grade. A univariate analysis showed that the Ki-67 labeling index >21% ( P<0.001), T-stage ( P<0.001) and nodal metastasis ( P=0.001) are determinants of recurrence. In the multivariate analysis, the Ki-67 labeling index >21% ( P<0.001), T-stage ( P<0.001) and nodal metastasis ( P<0.05) were independent predictors of recurrence. Kaplan-Meier plots of survival in patients with Ki-67 values above and below the median (21%) of the general study population showed that a high Ki-67 labeling index correlated with a shorter disease-free survival ( P<0.0001). The analysis of the Ki-67 labeling index at the time of initial surgery may be a powerful prognostic marker for patients with laryngeal squamous cell carcinoma and may be useful for selecting subgroups of patients who should be treated with more aggressive therapies.