Increased expression of senescence markers p14(ARF) and p16(INK4a) in breast cancer is associated with an increased risk of disease recurrence and poor survival outcome

In Vitro Investigation of Therapy-Induced Senescence and Senescence Escape in Breast Cancer Cells Using Novel Flow Cytometry-Based Methods

Although cellular senescence was originally defined as an irreversible form of cell cycle arrest, in therapy-induced senescence models, the emergence of proliferative senescence-escaped cancer cells has been reported by several groups, challenging the definition of senescence. Indeed, senescence-escaped cancer cells may contribute to resistance to cancer treatment. Here, to study senescence escape and isolate senescence-escaped cells, we developed novel flow cytometry-based methods using the proliferation marker Ki-67 and CellTrace CFSE live-staining. We investigated the role of a novel senescence marker (DPP4/CD26) and a senolytic drug (azithromycin) on the senescence-escaping ability of MCF-7 and MDA-MB-231 breast cancer cells. Our results show that the expression of DPP4/CD26 is significantly increased in both senescent MCF-7 and MDA-MB-231 cells. While not essential for senescence induction, DPP4/CD26 contributed to promoting senescence escape in MCF-7 cells but not in MDA-MB-231 cells. Our results also confirmed the potential senolytic effect of azithromycin in senescent cancer cells. Importantly, the combination of azithromycin and a DPP4 inhibitor (sitagliptin) demonstrated a synergistic effect in senescent MCF-7 cells and reduced the number of senescence-escaped cells. Although further research is needed, our results and novel methods could contribute to the investigation of the mechanisms of senescence escape and the identification of potential therapeutic targets. Indeed, DPP4/CD26 could be a promising marker and a novel target to potentially decrease senescence escape in cancer.

The impact of the senescent microenvironment on tumorigenesis: Insights for cancer therapy

The growing global burden of cancer, especially among people aged 60 years and over, has become a key public health issue. This trend suggests the need for a deeper understanding of the various cancer types in order to develop universally effective treatments. A prospective area of research involves elucidating the interplay between the senescent microenvironment and tumor genesis. Currently, most oncology research focuses on adulthood and tends to ignore the potential role of senescent individuals on tumor progression. Senescent cells produce a senescence-associated secretory phenotype (SASP) that has a dual role in the tumor microenvironment (TME). While SASP components can remodel the TME and thus hinder tumor cell proliferation, they can also promote tumorigenesis and progression via pro-inflammatory and pro-proliferative mechanisms. To address this gap, our review seeks to investigate the influence of senescent microenvironment changes on tumor development and their potential implications for cancer therapies.

Elongin B promotes breast cancer progression by ubiquitinating tumor suppressor p14/ARF

Elongin B (ELOB), a pivotal element in the ELOB/c-Cullin2/5-SOCS-box E3 ubiquitin-protein ligase complex, plays a significant role in catalyzing the ubiquitination and subsequent degradation of a broad spectrum of target proteins. Notably, it is documented to facilitate these processes. However, the regulatory role of ELOB in breast cancer remains ambiguous. In this study, through bio-informatic analysis of The Cancer Genome Atlas and Fudan University Shanghai Cancer Center database, we demonstrated that ELOB was over-expressed in breast cancer tissues and was related to unfavorable prognosis. Additionally, pathway enrichment analysis illustrated that high expression of ELOB was associated with multiple cancer promoting pathways, like cell cycle, DNA replication, proteasome and PI3K - Akt signaling pathway, indicating ELOB as a potential anticancer target. Then, we confirmed that both in vivo and in vitro, the proliferation of breast cancer cells could be significantly suppressed by the down-regulation of ELOB. Mechanically, immunoprecipitation and in vivo ubiquitination assays prompted that, as the core element of Cullin2-RBX1-ELOB E3 ligase (CRL2) complex, ELOB regulated the ubiquitination and the subsequent degradation of oncoprotein p14/ARF. Moreover, the anticancer efficacy of erasing ELOB could be rescued by simultaneous knockdown of p14/ARF. Finally, through analyzing breast cancer tissue microarrays and western blot of patient samples, we demonstrated that the expression of ELOB in tumor tissues was elevated in compared to adjacent normal tissues. In conclusion, ELOB is identified to be a promising innovative target for the drug development of breast cancer by promoting the ubiquitination and degradation of oncoprotein p14/ARF.

A Conversation with ChatGPT on Contentious Issues in Senescence and Cancer Research

Artificial intelligence (AI) platforms, such as Generative Pretrained Transformer (ChatGPT), have achieved a high degree of popularity within the scientific community due to their utility in providing evidence-based reviews of the literature. However, the accuracy and reliability of the information output and the ability to provide critical analysis of the literature, especially with respect to highly controversial issues, has generally not been evaluated. In this work, we arranged a question/answer session with ChatGPT regarding several unresolved questions in the field of cancer research relating to therapy-induced senescence (TIS), including the topics of senescence reversibility, its connection to tumor dormancy, and the pharmacology of the newly emerging drug class of senolytics. ChatGPT generally provided responses consistent with the available literature, although occasionally overlooking essential components of the current understanding of the role of TIS in cancer biology and treatment. Although ChatGPT, and similar AI platforms, have utility in providing an accurate evidence-based review of the literature, their outputs should still be considered carefully, especially with respect to unresolved issues in tumor biology. SIGNIFICANCE STATEMENT: Artificial Intelligence platforms have provided great utility for researchers to investigate biomedical literature in a prompt manner. However, several issues arise when it comes to certain unresolved biological questions, especially in the cancer field. This work provided a discussion with ChatGPT regarding some of the yet-to-be-fully-elucidated conundrums of the role of therapy-induced senescence in cancer treatment and highlights the strengths and weaknesses in utilizing such platforms for analyzing the scientific literature on this topic.

Immunoexpression of HER2 pathway related markers in HER2 invasive breast carcinomas treated with trastuzumab

PURPOSE

We evaluated the immunoexpression of potential markers involved in the HER2 pathway in invasive breast carcinoma with HER2 amplification treated with trastuzumab.

METHODS

Samples of ninety patients diagnosed and treated at two public Brazilian hospitals with overexpressed invasive carcinoma between 2009 and 2018 were included. Several markers (Bcl-2, CDK4, cyclin D1, EGFR, IGF1, IGF-1R, MDM2, MUC4, p16, p21, p27, p53, PTEN, RA, TNFα, and VEGF) were immune analyzed in the tumor by immunohistochemistry and then correlated with clinicopathological variables.

RESULTS

Tumor sample expression results determined potential markers of good prognosis with statistically significant values: cyclin D1 with a nuclear grade, and recurrence; IGF-1 with tumor size, and death; p16 with a response after treatment; PTEN with a response after treatment, and death. Markers of poor prognosis: p53 with histological, and nuclear grade; IGF-1R with a compromised lymph node. The treatment resistance rate after trastuzumab was 40%; the overall survival was 4.13 years (95% CI 5.1-12.5) and the disease-free survival was 3.6 years (95% CI 5.1-13.1).

CONCLUSIONS

The tumor samples profile demonstrated that cyclin D1, IGF-1, p16, and PTEN presented the potential for a good prognosis and p53 and IGF-1R for worse.

Therapy-induced senescence as a component of tumor biology: Evidence from clinical cancer

Therapy-Induced Senescence (TIS) is an established response to anticancer therapy in a variety of cancer models. Ample evidence has characterized the triggers, hallmarks, and functional outcomes of TIS in preclinical studies; however, limited evidence delineates TIS in clinical cancer (human tumor samples). We examined the literature that investigated the induction of TIS in samples derived from human cancers and highlighted the major findings that suggested that TIS represents a main constituent of tumor biology. The most frequently utilized approach to identify TIS in human cancers was to investigate the protein expression of senescence-associated markers (such as cyclins, cyclin-dependent kinase inhibitors, Ki67, DNA damage repair response markers, DEC1, and DcR1) via immunohistochemical techniques using formalin-fixed paraffin-embedded (FFPE) tissue samples and/or testing the upregulation of Senescence-Associated β-galactosidase (SA-β-gal) in frozen sections of unfixed tumor samples. Collectively, and in studies where the extent of TIS was determined, TIS was detected in 31-66% of tumors exposed to various forms of chemotherapy. Moreover, TIS was not only limited to both malignant and non-malignant components of tumoral tissue but was also identified in samples of normal (non-transformed) tissue upon chemo- or radiotherapy exposure. Nevertheless, the available evidence continues to be limited and requires a more rigorous assessment of in vivo senescence based on novel approaches and more reliable molecular signatures. The accurate assessment of TIS will be beneficial for determining its relevant contribution to the overall outcome of cancer therapy and the potential translatability of senotherapeutics.

Impairment of IgG Fc functions promotes tumor progression and suppresses NK cell antitumor actions

Natural killer (NK) cells mediate antibody dependent cytotoxic killing of cancer cells via cross-linking FcγR on NK cells with IgG-Fc. Studies have shown that the single-hinge cleaved IgGs (scIgGs) have dysfunctional Fc and failed engagement with FcγRs on immune cells. However, little is known about how scIgGs impact on antitumor immunity in the tumor microenvironment. In this study, we revealed a significant association of tumor scIgGs with tumor progression and poor outcomes of breast cancer patients (n = 547). Using multiple mouse tumor models, we demonstrated that tumor scIgGs reduced NK cell cytotoxic activities and resulted in aggressive tumor progression. We further showed that an anti-hinge specific monoclonal antibody (AHA) rescued the dysfunctional Fc in scIgGs by providing a functional Fc and restored NK cell cytotoxic activity. These findings point to a novel immunotherapeutic strategy to enhance Fc engagement with FcγRs for activation of anticancer immunity.

Therapy-Induced Senescence: Opportunities to Improve Anticancer Therapy

Cellular senescence is an essential tumor suppressive mechanism that prevents the propagation of oncogenically activated, genetically unstable, and/or damaged cells. Induction of tumor cell senescence is also one of the underlying mechanisms by which cancer therapies exert antitumor activity. However, an increasing body of evidence from preclinical studies demonstrates that radiation and chemotherapy cause accumulation of senescent cells (SnCs) both in tumor and normal tissue. SnCs in tumors can, paradoxically, promote tumor relapse, metastasis, and resistance to therapy, in part, through expression of the senescence-associated secretory phenotype. In addition, SnCs in normal tissue can contribute to certain radiation- and chemotherapy-induced side effects. Because of its multiple roles, cellular senescence could serve as an important target in the fight against cancer. This commentary provides a summary of the discussion at the National Cancer Institute Workshop on Radiation, Senescence, and Cancer (August 10-11, 2020, National Cancer Institute, Bethesda, MD) regarding the current status of senescence research, heterogeneity of therapy-induced senescence, current status of senotherapeutics and molecular biomarkers, a concept of "one-two punch" cancer therapy (consisting of therapeutics to induce tumor cell senescence followed by selective clearance of SnCs), and its integration with personalized adaptive tumor therapy. It also identifies key knowledge gaps and outlines future directions in this emerging field to improve treatment outcomes for cancer patients.

Breast Cancer and p16: Role in Proliferation, Malignant Transformation and Progression

The definition of new molecular biomarkers could provide a more reliable approach in predicting the prognosis of invasive breast cancers (IBC). The aim of this study is to analyze the expression of p16 protein in IBC, as well as its participation in malignant transformation. The study included 147 patients diagnosed with IBC. The presence of non-invasive lesions (NIL) was noted in each IBC and surrounding tissue. p16 expression was determined by reading the percentage of nuclear and/or cytoplasmic expression in epithelial cells of IBC and NIL, but also in stromal fibroblasts. Results showed that expression of p16 increases with the progression of cytological changes in the epithelium; it is significantly higher in IBC compared to NIL (p < 0.0005). Cytoplasmic p16 expression is more prevalent in IBC (76.6%), as opposed to nuclear staining, which is characteristic of most NIL (21.1%). There is a difference in p16 expression between different molecular subtypes of IBC (p = 0.025). In the group of p16 positive tumors, pronounced mononuclear infiltrates (p = 0.047) and increased expression of p16 in stromal fibroblasts (p = 0.044) were noted. In conclusion, p16 protein plays an important role in proliferation, malignant transformation, as well as in progression from NIL to IBC.

Possibility of inducing tumor cell senescence during therapy

The treatment options for cancer include surgery, radiotherapy and chemotherapy. However, the traditional approach of high-dose chemotherapy brings tremendous toxic side effects to patients, as well as potentially causing drug resistance. Drug resistance affects cell proliferation, cell senescence and apoptosis. Cellular senescence refers to the process in which cells change from an active proliferative status to a growth-arrested status. There are multiple factors that regulate this process and cellular senescence is activated by various pathways. Senescent cells present specific characteristics, such as an increased cell volume, flattened cell body morphology, ceased cell division and the expression of β-galactosidase. Tumor senescence can be categorized into replicative senescence and premature senescence. Cellular senescence may inhibit the occurrence and development of tumors, serving as an innovative strategy for the treatment of cancer. The present review mainly focuses on senescent biomarkers, methods for the induction of cellular senescence and its possible application in the treatment of cancer.

Ribosomal RNA Transcription Regulation in Breast Cancer

Ribosome biogenesis is a complex process that is responsible for the formation of ribosomes and ultimately global protein synthesis. The first step in this process is the synthesis of the ribosomal RNA in the nucleolus, transcribed by RNA Polymerase I. Historically, abnormal nucleolar structure is indicative of poor cancer prognoses. In recent years, it has been shown that ribosome biogenesis, and rDNA transcription in particular, is dysregulated in cancer cells. Coupled with advancements in screening technology that allowed for the discovery of novel drugs targeting RNA Polymerase I, this transcriptional machinery is an increasingly viable target for cancer therapies. In this review, we discuss ribosome biogenesis in breast cancer and the different cellular pathways involved. Moreover, we discuss current therapeutics that have been found to affect rDNA transcription and more novel drugs that target rDNA transcription machinery as a promising avenue for breast cancer treatment.

An interdependent network of functional enhancers regulates transcription and EZH2 loading at the INK4a/ARF locus

The INK4a/ARF locus encodes important cell-cycle regulators p14ARF, p15INK4b, and p16INK4a. The neighboring gene desert to this locus is the most reproducible GWAS hotspot that harbors one of the densest enhancer clusters in the genome. However, how multiple enhancers that overlap with GWAS variants regulate the INK4a/ARF locus is unknown, which is an important step in linking genetic variation with associated diseases. Here, we show that INK4a/ARF promoters interact with a subset of enhancers in the cluster, independent of their H3K27ac and eRNA levels. Interacting enhancers transcriptionally control each other and INK4a/ARF promoters over long distances as an interdependent single unit. The deletion of even a single interacting enhancer results in an unexpected collapse of the entire enhancer cluster and leads to EZH2 enrichment on promoters in an ANRIL-independent manner. Dysregulated genes genome-wide mimic 9p21-associated diseases under these scenarios. Our results highlight intricate dependencies of promoter-interacting enhancers on each other.

Senescence and Cancer: A Review of Clinical Implications of Senescence and Senotherapies

Cellular senescence is a key component of human aging that can be induced by a range of stimuli, including DNA damage, cellular stress, telomere shortening, and the activation of oncogenes. Senescence is generally regarded as a tumour suppressive process, both by preventing cancer cell proliferation and suppressing malignant progression from pre-malignant to malignant disease. It may also be a key effector mechanism of many types of anticancer therapies, such as chemotherapy, radiotherapy, and endocrine therapies, both directly and via bioactive molecules released by senescent cells that may stimulate an immune response. However, senescence may contribute to reduced patient resilience to cancer therapies and may provide a pathway for disease recurrence after cancer therapy. A new group of drugs, senotherapies, (drugs which interact with senescent cells to interfere with their pro-aging impacts by either selectively destroying senescent cells (senolytic drugs) or inhibiting their function (senostatic drugs)) are under active investigation to determine whether they can enhance the efficacy of cancer therapies and improve resilience to cancer treatments. Senolytic drugs include quercetin, navitoclax, and fisetin and preclinical and early phase clinical data are emerging of their potential role in cancer treatments, although none are yet in routine use clinically. This article provides a review of these issues.

Intravenous 5-fluoro-2'-deoxycytidine administered with tetrahydrouridine increases the proportion of p16-expressing circulating tumor cells in patients with advanced solid tumors

PURPOSE

Following promising responses to the DNA methyltransferase (DNMT) inhibitor 5-fluoro-2'-deoxycytidine (FdCyd) combined with tetrahydrouridine (THU) in phase 1 testing, we initiated a non-randomized phase 2 study to assess response to this combination in patients with advanced solid tumor types for which tumor suppressor gene methylation is potentially prognostic. To obtain pharmacodynamic evidence for DNMT inhibition by FdCyd, we developed a novel method for detecting expression of tumor suppressor protein p16/INK4A in circulating tumor cells (CTCs).

METHODS

Patients in histology-specific strata (breast, head and neck [H&N], or non-small cell lung cancers [NSCLC] or urothelial transitional cell carcinoma) were administered FdCyd (100 mg/m2) and THU (350 mg/m2) intravenously 5 days/week for 2 weeks, in 28-day cycles, and progression-free survival (PFS) rate and objective response rate (ORR) were evaluated. Blood specimens were collected for CTC analysis.

RESULTS

Ninety-three eligible patients were enrolled (29 breast, 21 H&N, 25 NSCLC, and 18 urothelial). There were three partial responses. All strata were terminated early due to insufficient responses (H&N, NSCLC) or slow accrual (breast, urothelial). However, the preliminary 4-month PFS rate (42%) in the urothelial stratum exceeded the predefined goal-though the ORR (5.6%) did not. An increase in the proportion of p16-expressing cytokeratin-positive CTCs was detected in 69% of patients evaluable for clinical and CTC response, but was not significantly associated with clinical response.

CONCLUSION

Further study of FdCyd + THU is potentially warranted in urothelial carcinoma but not NSCLC or breast or H&N cancer. Increase in the proportion of p16-expressing cytokeratin-positive CTCs is a pharmacodynamic marker of FdCyd target engagement.

Association between genetic variants at 9p21 locus with risk of breast cancer: A systematic review and meta-analysis

Breast cancer (BC) is the most frequent tumor in women and genetic factors are among the main risk factors contributing to this malignancy. Chromosome 9p21 contains important regulatory non-coding RNAs and is associated with multiple malignancies including BC. The current meta-analysis aimed to investigate the association between genetic variants within the 9p21 locus and risk of breast cancer. A literature search was performed using PubMed, Web of Science, Embase, MEDLINE, Scopus and Clinical key databases. Nine studies containing 23,726 subjects were eligible for the final analysis and specific odds ratios (OR) and confidence intervals (95% CI) were evaluated to assess the strength of the associations. In the pooled analysis, there was an association between the genetic variations in 9p21 locus (CDKN2A/2B) with risk of breast cancer with a standard OR of 1.22 (95% CI: 1.04-1.45, P = 0.016; random-effects model), supporting the significance of this locus as a novel risk factor for breast cancer patients. In conclusion, our results showed that 9p21 region is positively associated with risk of BC and its polymorphisms may be a candidate marker for BC susceptibility.

Atorvastatin-induced senescence of hepatocellular carcinoma is mediated by downregulation of hTERT through the suppression of the IL-6/STAT3 pathway

Hepatocellular carcinoma (HCC), a hepatic malignancy, has a poor prognosis and contributes to cancer-related death worldwide. Cellular senescence is an anticancer therapeutic strategy that causes irreversible cell cycle arrest and enables immune-mediated clearance of cancer cells. Atorvastatin, an HMG-CoA reductase inhibitor, has been shown to inhibit tumor growth and induce apoptosis or autophagy in malignant tumors. However, whether atorvastatin can induce HCC cell senescence and the mechanisms involved are poorly understood. The effects of atorvastatin-induced senescence were examined in both HCC cells and mouse xenograft models. The phenomenon and mechanism of senescence were examined by cell cycle analysis, senescence-associated β-galactosidase (SA-β-gal) staining and western blotting in HCC cells, and HCC tissues from mice were analyzed by immunohistochemical (IHC) staining. We demonstrated that atorvastatin induced cell growth inhibition and G0/G1 phase cell cycle arrest, leading to senescence in HCC cells. Atorvastatin-induced senescence was independent of p53, p14, and p16, and atorvastatin not only decreased the secretion of IL-6, a major senescence-associated secretory phenotype (SASP) factor, and the phosphorylation of STAT3 but also inhibited the expression of hTERT, a catalytic subunit of telomerase. Supplementation with exogenous IL-6 reversed both atorvastatin-induced suppression of STAT3 phosphorylation and hTERT expression and atorvastatin-induced senescence. Overexpression of constitutively activated STAT3 rescued HCC cells from atorvastatin-induced hTERT suppression and senescence. Moreover, atorvastatin decreased tumor growth in mouse xenograft models. Consistent with these results, atorvastatin decreased the IL-6, p-STAT3, and hTERT levels and increased β-gal expression in tumor sections. Taken together, these data indicate that atorvastatin can induce atypical cellular senescence in HCC cells to inhibit tumor growth, an effect mediated by downregulation of hTERT through suppression of the IL-6/STAT3 pathway.

P16 as a marker of carcinoma in effusions and peritoneal washing

BACKGROUND

Considering the potential of p16 as a marker for diagnosis, prognosis and therapeutic response, the aim of this study was to assess its presence, via immunocytochemistry, in metastatic carcinoma of different primary sites and histological types obtained from effusions and peritoneal washings. A total of 118 samples including 85 of metastatic carcinoma and 33 samples of benign effusion/peritoneal washing were prepared by the plasma/thromboplastin method. Immunocytochemistry reactions were performed on cell block sections using antibodies against p16, claudin-4, MOC-31, calretinin, HBME and CD68.

RESULTS

P16 overexpression was observed in 88.23% of all carcinoma samples. All cervix adenocarcinoma samples showed p16 overexpression. Overexpression in adenocarcinomas of ovary, lung and breast was observed in 93.75, 93.10 and 75% of the samples, respectively. Overexpression was observed in all different histological types analyzed: small cell carcinoma (lung), squamous cell carcinoma (cervical) and urothelial carcinoma (bladder). The specificity of p16 for carcinoma detection was of 96.96%.

CONCLUSION

Overexpression of p16 was observed in most metastatic carcinoma, from different primary sites and histological types, obtained from effusions and peritoneal washings. Due to its high frequency of overexpression in metastatic carcinoma, p16 may play a possible role in tumor progression and it may be considered as a complementary diagnostic marker depending on histological type and primary site of carcinoma.

Cortical Brain Age from Pre-treatment to Post-chemotherapy in Patients with Breast Cancer

Chemotherapy-related cognitive impairment and associated brain changes may reflect accelerated brain aging; however, empirical evidence for this theory is limited. The purpose of this study was to measure brain aging in newly diagnosed patients with breast cancer treated with chemotherapy (n = 43) and compare its longitudinal change to that of controls (n = 50). Brain age indices, derived from cortical measures, were compared between women with breast cancer and matched healthy controls across 3 timepoints (time 1: pre-surgery, time 2: 1 month following chemotherapy completion, and time 3: 1-year post-chemotherapy). The breast cancer group showed a significant decrease in cortical thickness across the 3 timepoints (p < .001) and a trend towards significant increase in predicted brain age especially from pre-treatment (time 1) to post-chemotherapy (time 2) compared to controls (p = 0.08). Greater increase in predicted brain age was related to several clinical factors (HER-2 status, surgery type, and history of neoadjuvant chemotherapy) and greater decrease in cortical thickness was associated with greater decrease in performance on a verbal learning task from time 1 to time 3 (r = - 0.48, p < .01). This study demonstrated evidence of increased cortical brain aging in middle-aged patients with breast cancer following chemotherapy treatment that was associated with decreased verbal memory performance.

Role of PGRMC1 in cell physiology of cervical cancer

AIMS

The most frequent cancers among women worldwide. The mortality of cervical cancer has declined significantly primarily due to the widespread use of Pap smear tests as a screening test and therapeutic vaccination. However, cervical cancer still remains a severe disease among the female population, as the prognosis of metastatic cervical cancer is very poor.

KEY METHODS

In this study, we performed 2D-DIGE and MALDI-TOF/TOF MS to analyze differentially expressed proteins between HeLa and invasive HeLa-I5 cells..

KEY FINDINGS

According to our proteomics data, 68 differentially expressed proteins between the HeLa and HeLa-I5 cells were identified. One of these differentially expressed proteins, Progesterone receptor membrane component 1 (PGRMC1), was selected as a candidate for further studies. To correlate the role of PGRMC1 with cellular migration and cancer progression, small interfering RNA (siRNA) was used to knockdown the expression of PGRMC1. Similar function of PGRMC1 was also observed in two other cervical cancer lines, CaSki and ME-180.

SIGNIFICANCE

PGRMC1 plays an essential role in regulating cancer progression and metastasis of cervical cancer cells, thus serving as a potential therapeutic target for cervical cancer.

Differential expression of senescence tumour markers and its implications on survival outcomes of breast cancer patients

Breast cancer is a heterogeneous disease displaying different histopathological characteristics, molecular profiling and clinical behavior. This study describes the expression patterns of senescence markers P53, DEC1 and DCR2 and assesses their significance on patient survival as a single or combined marker with P16 or P14 using breast cancer progression series. One thousand and eighty (1080) patients with primary invasive ductal carcinoma, no special type, were recruited through an 11-year retrospective study period. We constructed tissue microarrays of normal, benign hyperplasia, ductal carcinoma in situ and invasive ductal carcinoma from each patient and performed immunohistochemical staining to study the protein expression. Statistical analysis includes Pearson chi-square, Kaplan-Meier log ran test and Cox proportional hazard regression were undertaken to determine the associations and predict the survival outcomes. P53, DEC1 and DCR2 expression correlated significantly with normal, benign, premalignant and malignant tissues with (p<0.05). The expression profile of these genes increases from normal to benign to premalignant and plateaued from premalignant to malignant phenotype. There is a significant association between P53 protein expression and age, grade, staging, lymphovascular invasion, estrogen receptor, progesterone receptor and HER2 whereas DCR2 protein expression significantly correlated with tumour grade, hormone receptors status and HER2 (p<0.05 respectively). P53 overexpression correlated with increased risk of relapse (p = 0.002) specifically in patients who did not receive hormone therapy (p = 0.005) or chemotherapy (p<0.0001). The combination of P53+/P16+ is significantly correlated with poor overall and disease-free survival, whereas a combination of P53+/P14+ is associated with worse outcome in disease-free survival (p<0.05 respectively). P53 overexpression appears to be a univariate predictor of poor disease-free survival. The expression profiles of DEC1 and DCR2 do not appear to correlate with patient survival outcomes. The combination of P53 with P16, rather P53 expression alone, appears to provide more useful clinical information on patient survival outcomes in breast cancer.

Cellular Senescence in the Treatment of Ovarian Cancer

Objective

This review aimed to update the research and development of cellular senescence in the treatment of ovarian cancer. We discussed the current mechanisms of senescence and the major biomarkers of senescence, especially the methods of cellular senescence in the treatment of ovarian cancer.

Materials and Methods

We collected all relevant studies in PubMed from 1995 to 2017. The search terms included senescence and cancer, senescence and ovarian cancer, senescence-associated secretory phenotype, ovarian cancer and chemotherapy, radiotherapy, or biotherapy. PubMed search with the key words senescence and ovarian cancer lists approximately 85 publications. After excluding the duplicated articles, we selected 68 articles most relevant to senescence and ovarian cancer in this review.

Results

Cellular senescence plays a key role in various biological processes of ovarian cancer, which is closely related with the occurrence, development, and treatment of ovarian cancer. Cellular senescence on the one hand can reduce the dose of chemotherapy in ovarian cancer; on the other hand, it also can solve the problem of tumor resistance to apoptosis. Therefore, cellular senescence has been shown to be the third intracellular mechanism of ovarian cancer prevention followed by cellular DNA repair and apoptosis.

Conclusions

In the near future, cellular senescence therapy could be a powerful tool for ovarian cancer treatment.

Immunostaining for p53 and p16CDKN2A Protein Is Not Predictive of Prognosis for Dogs with Malignant Mammary Gland Neoplasms

Mammary gland tumors (MGTs) are common in dogs and show a variable clinical behavior that is difficult to predict. Currently, few immunohistochemical markers have been established to predict the prognosis of a canine MGT. However, p53 immunostaining has been variably reported to be prognostic for canine MGTs. Additionally, while p16^CDK2NA protein (p16) immunostaining has been found to be prognostic for human breast cancers, this marker has never been evaluated as a prognostic marker for canine neoplasms. In the present study, the prognostic utility of p53 and p16 was evaluated in 35 canine malignant MGTs. It was observed that 19 (54%) dogs died due to their MGTs with an overall mean survival time (MST) of 882 days. Seven MGTs showed p53 immunostaining, but this was not significantly associated with death (4 of 7 vs. 15 of 28; p = 0.6) or MST (670 vs. 934 days; p = 0.57). Five dogs had MGTs with no p16 immunostaining, 28 MGTs had intermediate p16 immunostaining, and two MGTs had increased p16 immunostaining. Neither death due to MGT (4 of 5, 14 of 28, or 1 of 2; p = 0.28) nor MST (683, 927, and 307 days; p = 0.31) were significantly associated with p16 immunostaining. Interestingly, p53 immunostaining was significantly associated with an increase or loss of p16 immunostaining. This is the first time that p16 has been evaluated as a prognostic marker for canine neoplasms. While these results suggest that a proportion of canine MGTs develop by cellular mechanisms that alter both p53 and p16 expression, there was no evidence that defects in p53 or p16 alter the behavior of a MGT. Neither p53 nor p16 was found to significantly predict prognosis, although this could reflect the limited number of MGTs included in the study.

Combined Inhibition of mTOR and CDK4/6 Is Required for Optimal Blockade of E2F Function and Long-term Growth Inhibition in Estrogen Receptor-positive Breast Cancer

The cyclin dependent kinase (CDK)-retinoblastoma (RB)-E2F pathway plays a critical role in the control of cell cycle in estrogen receptor-positive (ER+) breast cancer. Small-molecule inhibitors of CDK4/6 have shown promise in this tumor type in combination with hormonal therapies, reflecting the particular dependence of this subtype of cancer on cyclin D1 and E2F transcription factors. mTOR inhibitors have also shown potential in clinical trials in this disease setting. Recent data have suggested cooperation between the PI3K/mTOR pathway and CDK4/6 inhibition in preventing early adaptation and eliciting growth arrest, but the mechanisms of the interplay between these pathways have not been fully elucidated. Here we show that profound and durable inhibition of ER+ breast cancer growth is likely to require multiple hits on E2F-mediated transcription. We demonstrate that inhibition of mTORC1/2 does not affect ER function directly, but does cause a decrease in cyclin D1 protein, RB phosphorylation, and E2F-mediated transcription. Combination of an mTORC1/2 inhibitor with a CDK4/6 inhibitor results in more profound effects on E2F-dependent transcription, which translates into more durable growth arrest and a delay in the onset of resistance. Combined inhibition of mTORC1/2, CDK4/6, and ER delivers even more profound and durable regressions in breast cancer cell lines and xenografts. Furthermore, we show that CDK4/6 inhibitor-resistant cell lines reactivate the CDK-RB-E2F pathway, but remain sensitive to mTORC1/2 inhibition, suggesting that mTORC1/2 inhibitors may represent an option for patients that have relapsed on CDK4/6 therapy. Mol Cancer Ther; 17(5); 908-20. ©2018 AACR.

The 9p21 locus: A potential therapeutic target and prognostic marker in breast cancer

Breast cancer is an important cause of cancer related mortality in women. Despite extensive efforts to identify valid biomarkers for risk stratification, there are relatively few with proven clinical utility. It is recognized that genetic factors play a major role in determining susceptibility to breast cancer. Recent genome-wide-association-studies and gene expression analysis have demonstrated that a locus on chromosome 9p21, which contains three genes; CDKN2B (encoding p15ink4b), CDKN2A (encoding p16ink4a and p14ARF) and the 3' end of CDKN2BAS (an antisense noncoding RNA in the INK4 locus [ANRIL]) are associated with an increased risk of this malignancy. ANRIL has a post transcriptional modulatory activity, which has been shown to perturb the expression of nearby genes and may play an important role in coordinating tissue remodeling through regulation of cell proliferation, apoptosis, aging, extra-cellular matrix remodeling, and inflammatory response. However, the role of ANRIL is not well understood in breast cancer. Hypermethylation of the p14^ARF and p16^INK4a genes is found in some tumor types. Nevertheless, further studies are necessary to confirm the clinical utility of these putative markers in risk stratification, or assessing prognosis. In this review, we have summarized the prognostic and therapeutic potential of the p14^ARF and p16^INK4a genes in patients with breast cancer.

Clinicopathological significance of p14ARF expression in lung cancer: a meta-analysis

BACKGROUND

p14ARF, a tumor suppressor protein, encoded by the p16 tumor suppressor gene, has been reported to be associated with the clinicopathological features of lung cancer. However, the evaluated outcomes were inconsistent and remained inconclusive. In this study, we conducted a meta-analysis to clarify the significance of p14ARF expression in lung cancer pathogenesis.

MATERIALS AND METHODS

Electronic databases, PubMed, Web of Knowledge, Embase, and CNKI, were retrieved to collect relevant articles with inclusion and exclusion criteria. Using Stata 12.0 software, 95% confidence intervals (CIs) and odds ratios (ORs) were calculated.

RESULTS

A total of 15 eligible case-control studies that evaluated the relationship between p14ARF expression and lung cancer were included in the meta-analysis. The results demonstrated that there were significant associations between p14ARF expression and the risk of non-small-cell lung cancer (NSCLC), lung adenocarcinoma, and lung squamous carcinoma (for NSCLC, OR =11.02, 95% CI =5.30-22.92; for lung adenocarcinoma, OR =7.28, 95% CI =3.92-13.50; and for lung squamous carcinoma, OR =14.40, 95% CI =2.83-73.24). In the stratified analysis based on race, significant associations between p14ARF expression and lung cancer risk were found in Chinese population and Caucasians (for Chinese population, OR = 7.02, 95% CI =4.48-11.00 and for Caucasians, OR =4.19, 95% CI =1.42-12.38). Furthermore, the expression of p14ARF was significantly associated with the TNM-stage of lung cancer in Chinese population (OR =2.07, 95% CI =1.38-3.10).

CONCLUSION

p14ARF expression was significantly associated with the risk of lung cancer. In addition, the data of the meta-analysis showed that there was a significant correlation between p14ARF expression and the TNM-stage of lung cancer in Chinese population.

p14 expression differences in ovarian benign, borderline and malignant epithelial tumors

BACKGROUND

Abnormalities in tumor suppressors p14, p16 and p53 are reported in several human cancers. In ovarian epithelial carcinogenesis, p16 and p53 show higher immunohistochemical staining frequencies in malignant tumors and are associated with poor prognoses. p14 was only analyzed in carcinomas, with conflicting results. There are no reports on its expression in benign and borderline tumors. This study aims to determine p14, p16 and p53 expression frequencies in ovarian benign, borderline and malignant tumors and their associations with clinical parameters.

METHODS

A cross-sectional study utilizing immunohistochemistry was performed on paraffin-embedded ovarian epithelial tumor samples. Clinical data were collected from medical records. Fisher's exact test and the Bonferroni correction were performed for frequency associations. Survival comparisons utilized Kaplan-Meier and log rank testing. Associations were considered significant when p < 0.05.

RESULTS

p14 absent expression was associated with malignant tumors (60 % positive) (p = 0.000), while 93 % and 94 % of benign and borderline tumors, respectively, were positive. p16 was positive in 94.6 % of carcinomas, 75 % of borderline and 45.7 % of benign tumors (p = 0.000). p53 negative staining was associated with benign tumors (2.9 % positive) (p = 0.016) but no difference was observed between borderline (16.7 %) and malignant tumors (29.7 %) (p = 0.560). No associations were found between expression rates, disease-free survival times or clinical variables. Carcinoma subtypes showed no difference in expression.

CONCLUSIONS

This is the first description of p14 expression in benign and borderline tumors. It remains stable in benign and borderline tumors, while carcinomas show a significant absence of staining. This may indicate that p14 abnormalities occur later in carcinogenesis. p16 and p53 frequencies increase from benign to borderline and malignant tumors, similarly to previous reports, possibly reflecting the accumulation of inactive mutant protein. The small sample size may have prevented statistically significant survival analyses and clinical correlations. Future studies should investigate genetic abnormalities in p14 coding sequences and include all types of ovarian epithelial tumors. Bigger sample sizes may be needed for significant associations.

T1 high-grade bladder carcinoma outcome: the role of p16, topoisomerase-IIα, survivin, and E-cadherin

High-grade papillary urothelial carcinoma with subepithelial connective tissue invasion (T1HG) is an aggressive disease at high risk of progression after transurethral resection/Bacillus Calmette-Guerin standardized therapy. The European Organization for Research and Treatment of Cancer has identified T1HG bladder carcinoma that is single and ≤3 cm in the largest dimension at first diagnosis as a category in which the prognosis cannot be further stratified based on conventional criteria. This category may benefit from biomarker analysis as a valuable tool to determine the patient's outcome. To further the issue of biomarkers in predicting aggressiveness in single T1HG bladder carcinoma ≤3 cm in greatest dimension at first diagnosis, we have conducted a validation study of the biomarker risk score set previously reported by our group. The study set included immunohistochemical detection of galectin-3, CD44, E-cadherin (E-CAD), CD138, p16, survivin, HYAL-1, and topoisomerase-IIα in 92 randomly selected specimens at participating institutions. Topoisomerase-IIα expression was identified as a predictor of disease-free survival. p16, survivin, and E-CAD expression predicted progression-free survival, but p16 and E-CAD also predicted overall survival. The current study validates a panel of immunohistochemical markers with the potential of being implemented in practice and supports the use of biomarkers in predicting aggressiveness in patients with first diagnosis of single T1HG bladder carcinoma ≤3 cm in greatest dimension and therefore in identifying patients who need closer surveillance or earlier aggressive treatment.