Aberrant Expression of the Cell Polarity Regulator aPKCλ/ι is Associated With Disease Progression in Cervical Intraepithelial Neoplasia (CIN): A Possible Marker for Predicting CIN Prognosis

PRKCI Mediates Radiosensitivity via the Hedgehog/GLI1 Pathway in Cervical Cancer

Objective

Insensitivity to radiotherapy accounts for the majority of therapeutic failures in cervical cancer (CC) patients who undergo radical radiotherapy. We aimed to elucidate the molecular mechanisms underlying radiosensitivity to identify methods to improve the overall 5-year survival rate. The atypical protein kinase C iota (aPKCι) gene PRKCI exhibits tumor-specific copy number amplification (CNA) in CC. We investigated how PRKCI decreases radiosensitivity in CC and assessed the interplay between PRKCI and the Hedgehog (Hh)/GLI1 pathway in the present research.

Methods

The biological functions of PRKCI in CC radiosensitivity were explored through immunohistochemistry, colony formation, Cell Counting Kit-8 (CCK-8), cell cycle, apoptosis assays, and xenograft models. qRT-PCR, Western blotting analysis, and immunofluorescence assays were utilized to evaluate the interplay between PRKCI and the Hh/GLI1 pathway and its mechanism in PRKCI-decreased radiosensitivity in CC. Furthermore, the effect of auranofin (AF), a selective inhibitor of PKCι, on CC cells was explored through biochemical assays in vitro and in vivo.

Results

We found that high PRKCI expression was responsible for decreased survival in CC. PRKCI was intimately associated with radiation-triggered alterations in proliferation, the cell cycle, apoptosis, and xenograft growth. The Hh/GLI1 pathway was activated when PRKCI expression was altered. PRKCI functions downstream of the Hh/GLI1 pathway to phosphorylate and activate the transcription factor GLI1. AF acts as a radiosensitizer and showed biological effects in vitro and in vivo.

Conclusions

PRKCI is a therapeutic target for regulating radiosensitivity in CC. This molecule regulates radiosensitivity by modulating GLI1 relocalization and phosphorylation in CC via the Hh/GLI1 pathway.

3q26 Amplifications in Cervical Squamous Carcinomas

Background: Squamous carcinomas of the uterine cervix often carry mutations of the gene encoding for the catalytic sub-unit of kinase PI3K, PIK3CA. The locus of this gene at chromosome 3q26 and neighboring loci are also commonly amplified. The landscape of 3q26-amplified cases have not been previously characterized in detail in cervical cancer. Methods: Published genomic data and associated clinical data from TCGA cervical cancer cohort were analyzed at cBioportal for amplifications in genes at 3q26. The clinical and molecular characteristics of the group of patients with 3q26 amplifications was compared with the group without 3q26 amplifications. Comparative prevalence of amplification and expression of genes at 3q26 in amplified squamous cervical cancer cases were surveyed as well as 3q26 amplifications in cervical cancer cell line databases. Results: Amplification of 3q26 locus is a prevalent molecular lesion in cervical squamous cell carcinomas encountered in about 15% of cases in TCGA cohort of 247 patients. Cancer-related genes commonly amplified from 3q26 include PIK3CA, TBL1XR1, DCUN1D1, SOX2, MECOM, PRKCI, and TERC. Amplified cases do not completely overlap with PIK3CA mutant cases. Differences exist between 3q26-amplified and non-amplified carcinomas in the frequency of mutations and frequency of other amplifications. Most commonly over-expressed genes in 3q26 amplified cases include PIK3CA, TBL1XR1, DCUN1D1, and less commonly SOX2 and PRKCI. Conclusion: The subset of squamous cervical carcinomas with 3q26 amplifications is not overlapping with cancers carrying PIK3CA mutations and contains, besides PIK3CA, other cancer-associated genes that are over-expressed at the mRNA level, including TBL1XR1 and DCUN1D1. DCUN1D1, a regulator of SCF ubiquitin ligase activity, may be a relevant pathogenic player given the importance of ubiquitination and the proteasome in the disease. These observations could form the basis for therapeutic exploitation in this subset of squamous cervical carcinomas.

Glyoxalase 1 and protein kinase Cλ as potential therapeutic targets for late-stage breast cancer

Cancer cells upregulate the expression levels of glycolytic enzymes in order to reach the increased glycolysis required. One such upregulated glycolytic enzyme is glyoxalase 1 (GLO 1), which catalyzes the conversion of toxic methylglyoxal to nontoxic S-D-lactoylglutathione. Protein kinase Cλ (PKCλ) is also upregulated in various types of cancer and is involved in cancer progression. In the present study, the association between enhanced glycolysis and PKCλ in breast cancer was investigated. In human breast cancer, high GLO 1 expression was associated with high PKCλ expression at the protein (P<0.01) and mRNA levels (P<0.01). Furthermore, Wilcoxon and Cox regression model analysis revealed that patients with stage III-IV tumors with high GLO 1 and PKCλ expression had poor overall survival compared with patients expressing lower levels of these genes [P=0.040 (Gehan-Breslow generalized Wilcoxon test) and P=0.031 (hazard ratio, 2.36; 95% confidence interval, 1.08-5.16), respectively]. Treatment of MDA-MB-157 and MDA-MB-468 human basal-like breast cancer cells with TLSC702 (a GLO 1 inhibitor) and/or aurothiomalate (a PKCλ inhibitor) reduced both cell viability and tumor-sphere formation. These results suggested that GLO 1 and PKCλ were cooperatively involved in cancer progression and contributed to a poor prognosis in breast cancer. In conclusion, GLO 1 and PKCλ serve as potentially effective therapeutic targets for treatment of late-stage human breast cancer.

The Natural History of Cervical Intraepithelial Neoplasia Grades 1, 2, and 3: A Systematic Review and Meta-analysis

OBJECTIVE

The aim of the study was to obtain an updated overview of regression, persistence, and progression rates of conservatively managed cervical intraepithelial neoplasia grade 1 (CIN 1)/CIN 2/CIN 3.

METHODS

Data sources were MEDLINE, Embase, and Cochrane (January 1, 1973-April 14, 2020). Two reviewers extracted data and assessed risk of bias. To estimate outcome rates, we pooled proportions of the individual study results using random-effects meta-analysis, resulting in point estimates and corresponding 95% CIs. Heterogeneity was quantified by the I2 and τ2 measures.

RESULTS

Eighty-nine studies were included, 63 studies on CIN 1 (n = 6,080-8,767), 42 on CIN 2 (n = 2,909-3,830), and 7 on CIN 3 (n = 245-351). The overall regression, persistence, and progression to CIN 2 or worse and CIN 3 or worse rates for women with conservatively managed CIN 1 were 60% (95% CI = 55-65, I2 = 92%), 25% (95% CI = 20-30, I2 = 94%), 11% (95% CI = 8-13, I2 = 89%), and 2% (95% CI = 1-3, I2 = 82%), respectively. The overall regression, persistence, and progression rates for CIN 2 were 55% (95% CI = 50-60, I2 = 85%), 23% (95% CI = 19-28, I2 = 83%), and 19% (95% CI = 15-23, I2 = 88%), respectively. Finally, for CIN 3, these were 28% (95% CI = 17-41, I2 = 68%), 67% (95% CI = 36-91, I2 = 84%), and 2% (95% CI = 0-25, I2 = 95%), respectively. Cervical intraepithelial neoplasia grade 2 regression was significantly higher in women 30 years or younger and high-risk human papillomavirus-negative women (66%, 95% CI = 62-70, I2 = 76%; 94%, 95% CI = 84-99, I2 = 60%). Only 2/7,180 (0.03%) and 10/3,037 (0.3%) of the CIN 1 and CIN 2 cases progressed to cervical cancer.

CONCLUSIONS

Most CIN 1/CIN 2 will regress spontaneously in less than 24 months, with the highest rates in high-risk human papillomavirus-negative and young women, whereas progression to cancer is less than 0.5%. Conservative management should be considered, especially in fertile women and with expected high compliance. Given the heterogeneity in regression rates of high-grade histology, this should be classified as CIN 2 or CIN 3 to guide management.

High PKCλ expression is required for ALDH1-positive cancer stem cell function and indicates a poor clinical outcome in late-stage breast cancer patients

Despite development of markers for identification of cancer stem cells, the mechanism underlying the survival and division of cancer stem cells in breast cancer remains unclear. Here we report that PKCλ expression was enriched in basal-like breast cancer, among breast cancer subtypes, and was correlated with ALDH1A3 expression (p = 0.016, χ²-test). Late stage breast cancer patients expressing PKCλ^high and ALDH1A3^high had poorer disease-specific survival than those expressing PKCλ^low and ALDH1A3^low (p = 0.018, log rank test for Kaplan-Meier survival curves: hazard ratio 2.58, 95% CI 1.24–5.37, p = 0.011, multivariate Cox regression analysis). Functional inhibition of PKCλ through siRNA-mediated knockdown or CRISPR-Cas9-mediated knockout in ALDH1^high MDA-MB 157 and MDA-MB 468 basal-like breast cancer cells led to increases in the numbers of trypan blue-positive and active-caspase 3-positive cells, as well as suppression of tumor-sphere formation and cell migration. Furthermore, the amount of CASP3 and PARP mRNA and the level of cleaved caspase-3 protein were enhanced in PKCλ-deficient ALDH1^high cells. An Apoptosis inhibitor (z-VAD-FMK) suppressed the enhancement of cell death as well as the levels of cleaved caspase-3 protein in PKCλ deficient ALDH1^high cells. It also altered the asymmetric/symmetric distribution ratio of ALDH1A3 protein. In addition, PKCλ knockdown led to increases in cellular ROS levels in ALDH1^high cells. These results suggest that PKCλ is essential for cancer cell survival and migration, tumorigenesis, the asymmetric distribution of ALDH1A3 protein among cancer cells, and the maintenance of low ROS levels in ALDH1-positive breast cancer stem cells. This makes it a key contributor to the poorer prognosis seen in late-stage breast cancer patients.

Aberrant Nuclear Localization of aPKCλ/ι is Associated With Poorer Prognosis in Uterine Cervical Cancer

We previously reported that aberrant expression of atypical protein kinase C λ/ι (aPKCλ/ι) in low-grade squamous intraepithelial uterine cervix lesions was associated with an increased risk of progression to higher grade. This study aimed to investigate aPKCλ/ι expression patterns in cervical squamous cell carcinoma (SCC) and its association with disease progression. We immunohistochemically assessed aPKCλ/ι expression in 168 SCC samples and 13 normal uterine cervix samples. In 69.0% of SCC cases, aPKCλ/ι was expressed more abundantly than in normal epithelium, but there was no significant association between aPKCλ/ι intensity and disease progression (P=0.087, Cochran-Mantel-Haenszel test). aPKCλ/ι in normal cervical epithelium was confined to the cytoplasm or intercellular junctions. In contrast, aPKCλ/ι was predominantly localized within the nucleus in 36.9% of SCC samples (P<0.001, χ test), and the prevalence was significantly increased relative to advanced tumor stage (P<0.001, Cochran-Mantel-Haenszel test). Moreover, patients with SCC with aPKCλ/ι nuclear localization had worse prognoses than those with cytoplasmic localization (P<0.001, log-rank test). aPKCλ/ι localization differed between the intraepithelial lesion and adjacent invasive cancer in 40% of cases, while the expression pattern was similar between primary and matched metastatic tumors. In conclusion, aPKCλ/ι nuclear localization in cervical cancer is associated with tumor progression and worse prognosis. This is the first report to show aberrant nuclear aPKCλ/ι localization in a subgroup of cervical cancer patients and its association with worse prognosis.

A fluorometric hybridization assay for detecting and genotyping high-risk human papillomavirus 16 and 18 in archival tissues of cervical specimens

Early diagnosis and genotyping of high-risk human papillomavirus (HR-HPV) in cervical tissue specimens is significant for cervical cancer prevention. A sensitive microplate fluorometric hybridization assay (MFHA) was designed for the detection of HPV DNA 16 and 18 in cervical tissue. Following optimization and validation of the method, 60 formalin-fixed and paraffin-embedded cervical samples representing different cervical intraepithelial neoplasia grades of HPV-associated lesions were tested to determine the sensitivity and specificity of the assay. Using consensus GP5+/6+ biotin-labeled primers to amplify a conserved region within the L1 gene, the amplicons were added to the microplate wells coated with specific probes for the hybridization of HPV 16 and 18 individually. Final detection was performed with streptavidin-AlexaFluor488 conjugated. The results were then compared with type-specific nested polymerase chain reaction (PCR) and colorimetric microplate assay. While the agreement between the results obtained by the type-specific nested PCR and fluorometric assay for the detection of both HR-HPV types was 100%, this agreement for the detection of HPV type 16 and 18 using microplate colorimetric assay was 94.2% and 85% respectively. Overall, the results of the fluorometric and colorimetric assays are promising for detecting both HR-HPV types in a large number of cervical tissue samples with the higher MFHA assay sensitivity.

Fragment-Based Drug Discovery of Potent Protein Kinase C Iota Inhibitors

Protein kinase C iota (PKC-ι) is an atypical kinase implicated in the promotion of different cancer types. A biochemical screen of a fragment library has identified several hits from which an azaindole-based scaffold was chosen for optimization. Driven by a structure-activity relationship and supported by molecular modeling, a weakly bound fragment was systematically grown into a potent and selective inhibitor against PKC-ι.

Clinical course of untreated cervical intraepithelial neoplasia grade 2 under active surveillance: systematic review and meta-analysis

OBJECTIVE

To estimate the regression, persistence, and progression of untreated cervical intraepithelial neoplasia grade 2 (CIN2) lesions managed conservatively as well as compliance with follow-up protocols.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) from 1 January 1973 to 20 August 2016.

ELIGIBILITY CRITERIA

Studies reporting on outcomes of histologically confirmed CIN2 in non-pregnant women, managed conservatively for three or more months.

DATA SYNTHESIS

Two reviewers extracted data and assessed risk of bias. Random effects model was used to calculate pooled proportions for each outcome, and heterogeneity was assessed using I² statistics.

MAIN OUTCOME MEASURES

Rates of regression, persistence, or progression of CIN2 and default rates at different follow-up time points (3, 6, 12, 24, 36, and 60 months).

RESULTS

36 studies that included 3160 women were identified (seven randomised trials, 16 prospective cohorts, and 13 retrospective cohorts; 50% of the studies were at low risk of bias). At 24 months, the pooled rates were 50% (11 studies, 819/1470 women, 95% confidence interval 43% to 57%; I²=77%) for regression, 32% (eight studies, 334/1257 women, 23% to 42%; I²=82%) for persistence, and 18% (nine studies, 282/1445 women, 11% to 27%; I²=90%) for progression. In a subgroup analysis including 1069 women aged less than 30 years, the rates were 60% (four studies, 638/1069 women, 57% to 63%; I²=0%), 23% (two studies, 226/938 women, 20% to 26%; I²=97%), and 11% (three studies, 163/1033 women, 5% to 19%; I²=67%), respectively. The rate of non-compliance (at six to 24 months of follow-up) in prospective studies was around 10%.

CONCLUSIONS

Most CIN2 lesions, particularly in young women (<30 years), regress spontaneously. Active surveillance, rather than immediate intervention, is therefore justified, especially among young women who are likely to adhere to monitoring.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2014: CRD42014014406.

[Nomenclature of squamous cell precursor lesions of the lower female genital tract : Current aspects]

The majority of precancerous lesions of the lower female genital tract (intraepithelial neoplasia, IN) are caused by human papillomavirus (HPV) infections resulting in cellular atypia and in turn an altered tissue architecture. Depending on the pathogenesis, a distinction is made between vulvar intraepithelial neoplasia (VIN) classified as classical VIN associated with high-risk HPV infections (u-VIN) and differentiated VIN (d-VIN), which is associated with lichen sclerosus et atrophicus and p53 alterations. In the current World Health Organization (WHO) classification a novel grading system for squamous cell precancerous lesions of the lower female genital tract has been proposed, differentiating low grade squamous intraepithelial lesions (L-SIL) including condyloma and HPV-associated alterations plus VIN 1, vaginal intraepithelial neoplasia (VaIN 1) and cervical intraepithelial neoplasia (CIN 1) from high grade squamous intraepithelial lesions (H-SIL) with VIN 2 and 3, VaIN 2 and 3 as well as CIN 2 and 3. The use of p16 immunohistochemistry can assist the differentiation. The new binary classification, however, contradicts the German cytological nomenclature (Munich nomenclature III), which differentiated three grades of dysplasia in order to avoid overtreatment of patients with moderate IN. The individual nomenclatures are compared to each other. It is recommended to report the grade of precancerous lesions in addition to the SIL classification of the WHO.

Lack of an association between the aPKCλ/ι expression in prostate cancer and the patient outcomes

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This is the first study to assess aPKCλ/ι expression in primary prostate cancer with metastatic disease.

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A total of 43 patients with prostate cancer and its metastasis to the lymph node and/or bone were analyzed in this study.

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We found no strong association between aPKCλ/ι expression and the prognosis of the patients.