High P53 Expression Research Articles

Analysis of Molecular Pretreated Tumor Profiles as Predictive Biomarkers of Therapeutic Response and Survival Outcomes after Neoadjuvant Therapy for Rectal Cancer in Moroccan Population.

Pathologic features depending on tumor response to preoperative chemoradiotherapy are important to determine the outcomes in patients with rectal cancer. Evaluating the potential predictive roles of biomarker expression and their prognostic impact is a promising challenge. We reported here the immunohistochemical staining of a panel marker of mismatch repair protein (MMR), Ki67, HER-2, and p53. Additionally, identification of somatic mutations of KRAS, NRAS, and BRAF genes were performed by direct sequencing and pyrosequencing in pretreated biopsy tissues from 57 patients diagnosed for rectal cancer. Clinical features and pathological criteria for postneoadjuvant treatment surgical resection specimen's data were collected. Immunohistochemical expression and mutational status were correlated with therapeutic response, overall survival, and disease progression. The mean age of patients was 56 years. Seven (12.3%) out of 57 patients had a complete therapeutic response. Our analysis showed that when using complete therapeutic response (Dworak 4) and incomplete therapeutic response (Dworak 3, 2, and 1) as grouping factor, high p53 expression at the pretreatment biopsy was significantly associated to an incomplete response (p = 0.002). For 20 and 2 out of 57, KRAS and NRAS mutations were detected, respectively. The majority of these mutations affected codon 12. KRAS mutations detected at codon 146 (A146T, A146V) was associated with the appearance of recurrence and distant metastasis (p = 0.019). A high expression of HER-2 corresponding to score 3+ was observed in 3 pretreatment biopsy specimens. This class was significantly associated with a short relapse-free survival (p = 0.002). Furthermore, the high expression of Ki67 was moderately correlated with an older age (p = 0.016, r = 0.319). In addition, this shows that high p53 expression in the pretreatment biopsy was associated with an incomplete response in surgical resection specimens after neoadjuvant treatment, and a HER-2 score 3+ can be a predictive factor of distant metastasis and local recurrence. Larger, prospective, and more studies are needed.

Clinical and Prognostic Implications of P21 (WAF1/CIP1) Expression in Patients with Esophageal Cancer: A Systematic Review and Meta-Analysis.

Background Previous studies have demonstrated that P21 (WAF1/CIP1) is a valuable prognostic factor in several malignant tumors. However, it is not known whether P21 can predict the prognosis in patients with esophageal cancer (EC). The aim of this research was to investigate the contribution of P21 expression to the clinicopathological characteristics and of EC. Methods A systematic review and meta-analysis of study focusing on P21 expression, clinicopathological characteristics, and clinical outcomes in patients with EC was performed using seven databases (PubMed, Embase, Web of Science, and four Chinese databases). Pooled hazard ratios and odds ratios were used to explore the association between P21 expression, clinicopathological characteristics, and outcomes in patients with EC. The heterogeneity of the studies was classified by the I2 statistic. The sensitivity analysis was then utilized to assess the robustness of the results. Finally, the funnel plot and Begg's test were used to evaluate the publication bias. Results Forty-five studies with 3098 patients were eligible for inclusion in the meta-analysis. Thirty of these studies reported on clinicopathological characteristics and 15 on clinical outcomes. The pooled hazard ratio of 1.456 (95% confidence intervals 1.033–2.053, P = 0.032) for overall survival indicated that a low P21 expression level was an unfavorable prognostic factor for a clinical outcome in patients with EC. Furthermore, the pooled odds ratio confirmed an association between decreased P21 expression and poor clinicopathological characteristics, including differentiation, lymph node metastasis, invasion, and higher grade and clinical stage. Notably, high P21 expression was a significant predictor of a favorable response to chemotherapy. There was no evidence of publication bias. Conclusion Reduced P21 expression is associated with a poor outcome in patients with EC.

Expression and clinical significance of p62 protein in colon cancer.

p62 is a multifunctional protein involved in multiple cellular processes including proliferation, drug sensitivity and autophagy-associated cancer cell growth. However, the role of p62 in colon cancer remains controversial. Here we investigated the expression of p62 protein in colon cancer and its clinical significance.Patients with colon adenocarcinoma who underwent resection at the Third Affiliated Teaching Hospital of Xinjiang Medical University (Affiliated Cancer Hospital) were retrospectively analyzed. The expression of p62 protein in tumor tissues and adjacent normal tissues was detected by immunohistochemistry and western-blotting. Real-time quantitative polymerase chain reaction was used to detect the expression level of p62 messenger ribonucleic acid in specimens. Progression-free survival (PFS) and overall survival (OS) were assessed using Kaplan-Meier method and the log-rank test.A total of 85 colon cancer patients were enrolled, including 55 (64.71%) patients with high p62 expression, and 30 (35.29%) patients with low p62 expression. The transcription and expression level of p62 in colon cancer tissues were higher than those in adjacent normal tissues (P < .01). High expression of p62 was an independent risk factor for the poor prognosis (PFS and OS) of colon cancer.p62 may be a potential indicator of determining the progression and prognosis evaluation of colon cancer.

Nomogram for prediction of pathologic complete remission using biomarker expression and endoscopic finding after preoperative chemoradiotherapy in rectal cancer.

ObjectiveThe aim of this study is to develop a nomogram for prediction of pathologic complete remission (pCR) after preoperative chemoradiotherapy (CRT) for rectal cancer.MethodsmRNA expression levels of seven molecular markers [p53, p21, Ki-67, vascular endothelial growth factor (VEGF), CD133, CD24, CD44] were measured by reverse transcriptase polymerase chain reaction (RT-PCR) in 120 rectal cancers. Endoscopic findings of clinical complete remission (cCR) and biologic variables were used to construct nomogram in the training group (n=80), which was validated in the validation group (n=40).ResultsmRNA expression levels of four markers (p53, p21, Ki67, CD133) correlated with pCR (24/80, 30.0%) in the training group. Low expression of p53 and/or high expression of p21, Ki67 and CD133 showed greater pCR rate. pCR was shown in 18 (69.2%) of 26 cases showing endoscopic cCR in the training group. Higher pCR rate was demonstrated in lower tumor location than middle tumor (19/49, 38.8% vs. 5/31, 16.1%). A nomogram for prediction of pCR was developed from the multivariate prediction model using these six variables, which showed good discrimination ability in the training group [area under the curve (AUC)=0.945] and validation group (AUC=0.922). The calibration plot showed good agreement between actual and predicted pCR in both patient groups. ConclusionsNomogram for assessment of pCR can be useful for making treatment decisions after CRT according to predicted responses.

Prognostic Significance of P16, EZH2, FOXJ1, and Tenascin Expression in Pediatric Ependymoma

Background: The prognosis of pediatric ependymomas remains poor, with treatment being predominantly based on surgery with or without radiotherapy. The lack of robust therapeutic molecular markers for clinical use has hampered attempts to improve survival from ependymomas. This study aimed to assess the prognostic significance of p16, enhancer of zeste homolog 2 (EZH2), forkhead box protein J 1 (FOXJ1), and tenascin in pediatric ependymomas by evaluating their immunohistochemical expression and comparing them with clinical outcomes. Methods: A total of 22 children (< 14 years) with ependymoma were retrospectively analyzed for the expression of p16, EZH2, FOXJ1, and tenascin by immunohistochemical staining. Kaplan-Meier analysis was used to evaluate the association between immunohistochemical marker expression and patient survival. Results: Higher expression of p16, EZH2, FOXJ1, and tenascin was observed in 59.0%, 36.3%, 40.9%, and 68.1% of the ependymoma samples, respectively. Patients with p16-positive and p16-negative tumors had an overall median survival time of 5.38 and 3.38 years and an overall cumulative survival rate of 44.5% and 36.5%, respectively. P16 negativity was significantly associated with poorer outcome (P = 0.009). No relationship was observed between EZH2, FOXJ1, and tenascin expression and overall survival (P = 0.904, 0.844, and 0.646, respectively). Conclusions: Loss of p16 expression was associated with poor prognosis and may be used for risk stratification. Limitations of the present study include its small sample size and variable sensitivity of different antibody clones and detection methods. Int J Clin Pediatr. 2020;9(3):67-71 doi: https://doi.org/10.14740/ijcp385

The association between expression of p53 and aggressiveness of serous adenocarcinoma of the uterine cervix

Background:Serous adenocarcinoma of the uterine cervix is an extremely rare variant of cervical adenocarcinoma. This study aimed to evaluate the clinicopathological and molecular features and outcomes of serous adenocarcinoma of the uterine cervix (SACC).Materials and Methods:This was a retrospective study conducted based on the clinical and pathological data of seven patients diagnosed with SACC after hysterectomy, who were evaluated at the gynecologic oncologic centers between 2010 and 2019.Results:Five cases were diagnosed at Stage IB and two at Stage IV. All patients underwent radical hysterectomy with bilateral salpingo-oophorectomy and subsequently received postoperative radiotherapy or chemotherapy. One patient showed persistent disease, and two patients suffered recurrence. Immunohistochemical study showed that three (43%) of the seven patients were positive for p53, and among these three patients, two with diffuse strong p53 expression experienced an aggressive course with recurrences at pelvic lymph nodes, lung, and brain.Conclusion:High p53 expression and advanced stage may be associated with poorer clinical outcomes in SACC, which suggest that immunohistochemistry may contribute to the prediction of prognosis.

MGMT expression in pituitary corticotroph adenomas and its relationship to clinical, pathological, and ultrastructural parameters in patients with Cushing's disease.

Transsphenoidal surgery is the treatment of choice in Cushing's disease (CD), although even late recurrences occur in some patients. Low expression of O-6-methylguanine-DNA methyltransferase (MGMT) has been linked to ahigh risk of relapse in pituitary tumours, but the evidence for corticotroph adenomas is limited. Therefore, we investigated whether MGMT expression was associated with CD remission or clinicopathological markers of tumour aggressiveness among patients with corticotroph adenomas. We included 72 consecutive patients (83% female, mean age ±SD: 44.15 ±15.15 years) with CD, who underwent transsphenoidal adenomectomy between 2012 and 2018. The invasiveness of corticotroph tumours was assessed based on the Knosp scale. Immunohistochemistry was used to analyse MGMT expression as well as the proliferation markers (Ki-67, p53, mitotic index). Electron microscopy was used to categorise tumours into densely or sparsely granulated. Early biochemical remission was evaluated in all patients 6 months after pituitary surgery. Early remission was observed in 47 (65%) patients 6 months after surgery. MGMT expression was > 75% in half of all tumours, < 25% in 14 tumours, and 25-50% or 50-75% in 11 tumours. Lower MGMT expression was associated with alarger tumour diameter (p = 0.001), higher adrenocorticotropic hormone (ACTH) concentration (p = 0.002), higher p53 expression (p = 0.026), and higher frequency of sparsely granulated corticotroph adenomas (p = 0.009). Low MGMT expression was significantly related to lower frequency of early clinical remission (p = 0.005). MGMT predicted the outcomes of transsphenoidal surgery for CD. Pituitary corticotroph adenomas with low MGMT expression may be associated with increased invasiveness and poorer prognosis.

The prognostic significance of serum CA125 levels with ER, PR, P53 and Ki-67 expression in endometrial carcinomas.

The present study evaluates the relationship between the expression levels of hormone receptors (HRs), Ki-67, p53 and serum cancer antigen 125 (CA125) levels in endometrial cancer and clinicopathological risk factors, and determines their prognostic values. This retrospective study included 49 patients with endometrial cancer whose estrogen receptor (ER) and progesterone receptor (PR) Ki-67 and p53 expression levels were determined through immunohistochemical methods, and whose preoperative serum CA125 levels were measured. These factors relationship with various clinicopathological factors, progression-free survival (PFS) and overall survival (OS) was investigated. The study included 49 patients with EC with a mean age of 61 ± 10 years. The rate of HR positivity was significantly higher in the endometrioid histology group than in the non-endometroid histology group (p = 0.026). A high level of Ki- 67 expression was found to be associated with a non-endometroid histology (p = 0.016), and a high tumor grade (p < 0.001) and a high p53 expression were found to be associated with advanced disease stage (p = 0.026). A positive correlation was found between p53 and Ki-67, a negative correlation was found between p53 and Ki-67 and the presence of HR. Significant relationship was not found between HR status, p53, Ki-67, CA125 and either other clinicopathological risk factors or survival. While HR positivity indicates favorable clinicopathological prognostic factors, high Ki-67 and high p53 expression indicate unfavorable ones. However, no direct effect of these factors on prognosis was found in this study.

Immunohistochemical detection of senescence markers in human sarcomas

Senescent cells in tumors are not inert cells but exert bystander effects by developing secretory phenotypes affecting the extracellular matrix and interfering the biological behavior of adjacent tumor cells. We assessed putative senescent cell content in a series of human sarcomas, using in parallel markers related to cell proliferation (Ki67), DNA damage (γH2Ax), lipofuscin detection (SenTraGor®) and two cyclin-dependent kinase CDK-inhibitors (p16/INK4a and p21/cip/waf21). Necrosis was directly linked with the size of tumors (p = 0.02, r = 0.25), number of mitosis (p = 0.05, r = 0.21) and inversely with the expression of γH2Ax (p = 0.01, r = 0.28). Smaller tumors (less than 3 cm) had a higher p16 expression (p = 0.07); Moreover, in group analysis, tumors with lack of expression of p16 had significantly higher necrosis score (p = 0.03). Linear regression analysis showed that p21 expression was strongly and directly related with MIB1 (p < 0.0001, r = 0.44) and with Lipofuscin expression (p = 0.02, r = 0.26). Senescence markers are extensively expressed in human sarcomas and correlated with histopathological features. However, p16, p21 and Lipofuscin expression show different patterns, suggesting that these markers may detect different senescence phenotypes. In addition, our data suggest that the novel marker SenTraGor® may detect phenotypes of senescent cells involving p21 activation.

Clinical Outcome of Mantle Cell Lymphoma Patients with High Risk Biology (high Ki-67, blastic MCL, or high p53 expression)

INTRODUCTION: Mantle cell lymphoma (MCL) is a distinct lymphoma subtype with a wide variation of clinical course. Previously a clinically defined risk score (MIPI) was established which partly reflects the heterogeneity of clinical outcome in this disease (Hoster, JCO 2004). Based on prospective trials, cytology (classical type vs. blastoid variant; Hoster, JCO 2016), cell proliferation as determined by Ki-67expression (Hoster, JCO 2016), and p53 alterations (Eskelund, Blood 2017; Aukema, Blood 2018) all have been identified as major drivers of a rapidly progressing disease, independent of MIPI. Aim of this study was to assess the clinical outcome of patients with at least one of these 3 different biological risk factors in a large uniformly treated patient population. METHODS: All patients were treated in the MCL Younger (Hermine, Lancet 2016) and MCL Elderly trials (Kluin-Nelemans, NEJM 2012) of the European MCL Network. Formalin fixed paraffin embedded (FFPE) diagnostic patients' material was classified as classical or blastic/pleomorphic variant and analyzed by Ki-67 or p53 immunohistochemistry on either tissue microarrays or whole tissue sections. Patients were classified as having high risk biology if they displayed blastoid cytomorphology, Ki-67 ≥30% according to the published guidelines, or high p53 staining indicating a mutated gene status expression. As control, standard risk disease patients had classical MCL with low Ki-67 &lt;30%, and p53 IHC expression ≤50%. RESULTS: In 365 MCL (MCL younger: n=192, MCL elderly: n=173) out of 1229 study patients, at least one of the biological parameters indicated a high risk biology, or high risk biology was excluded by determination of all 3 parameters. No major survival difference was observed for patients with and without IHC data available, excluding a major selection bias. 65 of 319 analysed cases displayed a blastoid cytomorphology (20%), 175 of 345 cases had an increased Ki-67&gt;30% (51%), and 54 of 254 cases displayed a mutated p53 status (21%). Based on the selection procedure of the cases, a total of 224 cased displayed a high risk biology (63%) vs 130 cases with confirmed standard risk disease(37%). Median failure-free (6.3 years vs, 2.2 years; p&lt; 0.0001) and overall survival (median not reached vs. 4 years; p&lt;0.0001) was significantly prolonged in the standard risk cohort compared with the high risk biology group. These significant differences were detected in both, patients treated with conventionally dosed chemotherapy (median PFS: 3.8 vs. 1.3 years, p=0.0001; OS: median not reached vs 2.5 years, p&lt;0.0001) as well as patients receiving a cytarabine containing induction and autologous transplantation (median PFS: 7.5 vs. 3.7 years, p=0.0011; OS: median not reached vs 6.5 years, p&lt;0.0001). Interestingly, MIPI remained a prognostic factor in the groups of patients without and with high-risk biology (FFS low risk disease: p=0.0223); PFS high risk disease: p&lt;0.0001), and distribution of risk groups differed only slightly in these subsets of patients (biological low risk: 51% low/32%intermediate/17% high MIPI; biological high risk: 31% low/35% intermediate/34% high MIPI). Similar results were observed for overall survival. CONCLUSIONS: Although our enrichment strategy does not allow the estimation of the frequency of high risk biology and the patient group with standard risk disease is underrepresented in this evaluation, the patients with high risk biology as defined by blastoid variant, Ki-67 &gt;30%, or high p53 expression had a significantly shorter failure-free and overall survival even without consideration of the clinical features of the disease (MIPI). As these biological factors seems to dictate the sometimes dismal clinical course of the disease, we recommend to incorporate these factors in routine diagnostic practice. Future studies should investigate the differential impact of targeted therapies in this biologically defined subset of patients. Disclosures Dreyling: Sandoz: Other: Scientific advisory board; Roche: Other: Scientific advisory board, Research Funding, Speakers Bureau; Novartis: Other: Scientific advisory board; Mundipharma: Other: Scientific advisory board, Research Funding; Janssen: Other: Scientific advisory board, Research Funding, Speakers Bureau; Gilead: Other: Scientific advisory board, Speakers Bureau; Celgene: Other: Scientific advisory board, Research Funding, Speakers Bureau; Acerta: Other: Scientific advisory board; Bayer: Other: Scientific advisory board, Speakers Bureau. Hoster:Roche Pharma AG: Other: Travel support; Janssen: Research Funding. Unterhalt:F. Hoffmann-La Roche: Research Funding. Hermine:AB science: Consultancy, Equity Ownership, Honoraria, Research Funding; Celgene: Research Funding; Novartis: Research Funding. Klapper:Roche, Takeda, Amgen, Regeneron: Honoraria, Research Funding.

413P - The state of molecular biological markers in osteosarcoma

BackgroundTo study of immunohistochemical markers of proliferation and apoptosis are important prognostic indicators for predicting the clinical course of tumours and the development of therapeutic tactics. MethodsThe p53 suppressor gene, the bcl-2 oncogene and the Ki-67 antigen are responsible for DNA repair, cell division and apoptosis. In all patients, tumour material was obtained using biopsies and operations. In tumour tissue samples fixed by neutral formalin with standard wiring and embedded in paraffin, tumour markers of apoptosis and proliferation were determined - p53, bcl-2, Ki – 67. A positive result was the presence of specific brown staining of the nuclei in the detection of the Ki-67 antigen and the p53 gene suppressor and the cytoplasm in the detection of the expression of bCl-2. ResultsCases where the nucleus or cytoplasm was not stained by reaction with antibodies to p53, Ki-67 and bcl-2 or the number of positive cells was less than 10%, the reaction was considered negative (0). Weak (1+) reaction was considered when staining 10-30% of cells; medium reaction (2+) - when staining 30-50% of cells; strong reaction (3+) - intense staining from 70 or more cells. We carried out a comparative assessment of the effectiveness of treatment of patients depending on the type of therapy and the phenotype of tumour cells. Among patients who received systemic chemotherapy, the full effect was observed in 13% of patients. With negative and weakly positive reactions to the mutant p53 gene and Ki 67 among them was 70.6%, and with moderate and strong expression of bcl-2 (80%). Patients with a phenotype of tumour cells with a negative or weakly positive IHC response to the mutant p53 gene (58.5% of patients), weakly positive expression of Ki 67 (70.6% of patients), and high expression of bcl-2 (46.4 % of patients). In 37.4% of patients from this group, the effect of therapy was negative, most of them had tumour cells with high expression of the mutant p53 and Ki 67 gene, and no expression of bcl-2. ConclusionsIt was established that with positive expression of p53 + Ki-67 + and negative bcl-2 parameters, patients had an unfavourable prognosis. Legal entity responsible for the studyRonc. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

Tumor stromal type is associated with stromal PD-L1 expression and predicts outcomes in breast cancer.

Background/AimThe aim of this study is to determine the relationship between stromal types, PD-L1 status and clinicopathological characteristics in patients with different molecular subtypes of breast cancer.Materials and methodsProtein expression levels of PD-L1 were determined by immunohistochemistry assay. Stromal type was classified based on the maturity of the tumor stroma.ResultsDifferent subtypes of breast cancer had distinct stromal types. Tumors from patients with mature stroma had lower pathological N stage and AJCC stage, more frequent high p53 expression and positive stromal PD-L1 staining. Hormone receptor negative patients had higher frequency of positive stromal PD-L1 staining. Stromal PD-L1 status was also associated with different breast cancer subtypes and EGFR expression level. Importantly, our data revealed that stromal types and stromal PD-L1 status were independent prognostic factors.ConclusionThis study highlighted the importance of stromal types and stromal PD-L1 status in determining clinical outcomes in patients with breast cancer, and suggested that stromal type classification might be readily incorporated into routine clinical risk assessment following curative resection or optimal therapeutic design.

Abstract 4627: Mutant p53 regulation in a Li-Fraumeni mouse model

Abstract The p53 tumor suppressor is maintained mainly at low physiological levels in normal cells by its two major inhibitors, Mdm2 and Mdm4. Mdm2 is a E3 ubiquitin ligase while Mdm4 binds to p53 and inhibits its transactivation activity. Deletion of either inhibitor results in p53-dependent embryonic lethality in mice. p53 is one of the most commonly mutated genes in human cancer. While we have gained considerable knowledge about wild-type p53 regulation and mode of action, our understanding of the oncogenic activity of mutant p53 lags behind. We know that mutant p53 is regulated in the same manner as wild-type p53. In a mouse model of Li-Fraumeni syndrome, Mdm2 binds and inhibits the hot spot mutant p53R172H (p53R175H in humans). Here we show that Mdm4, like Mdm2, regulates p53R172H stability in vivo, and that endogenous Mdm2 cannot compensate for this stabilization. Thus, mutant p53 mice that lack Mdm4 have stable high levels of p53R172H and display accelerated tumor development and an increased range of tumor types, compared to mutant p53 mice. Furthermore, when we compared mutant mice with the loss of two different alleles of both negative regulators, Mdm2 and Mdm4, we observed an even higher level of p53. This finding reveals that several tissues can tolerate high expression of oncogenic p53 and indicates a collaborative activity of these inhibitors in regulating mutant p53. The analysis of these mice uncovered new and unexpected functions of mutant p53 that we will discuss for the first time at the AACR 2019 meeting. Citation Format: Tamara Terzian, Molly Plehaty, Nema Sobhani, Wanida Stevens, Stefan Marasligiller, Tara Srinivas, Rohan Mylavarapu, Yvonne Clarke, Farinaz Arbab, Brendon Podell, Roderick Bronson. Mutant p53 regulation in a Li-Fraumeni mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4627.

Abstract 2061: A novel small molecule inhibitor of MDM2-p53 (APG-115) has antitumor activity in gastric adenocarcinoma

Abstract Background: The amplification of Murine Double Minute 2 (MDM2) and mutation of P53 are significant processes in the incidence of gastric cancer. APG-115, a small molecular inhibitor of MDM2-P53, is a novel potential anticancer agent. We aim to investigate the anticancer effect of APG-115 in gastric cancer. Methods: We selected 87 pairs of gastric cancer tissues (primary tumors and metastatic tissues). Using Immunohistochemistry (IHC) and Fluorescence in situ hybridization (FISH), we examined the expression and amplification of MDM2 and P53. Using MTS, we examined the anti-proliferation activity of APG-115 in five gastric cancer cell lines (AGS, MKN-45, BGC-823, NCI-N87, NUGC-3) by CCK-8 assay. We used western blot analysis and siRNA interference for mechanism exploration to examine the anti-cancer activity of APG-115 in p53 wild type gastric cancer cell lines. Gastric cancer cell xenograft nude mice models were used for in vivo efficacy evaluation. Results: We examined 87 pairs of gastric cancer tissues in IHC. The results suggested that the primary tumors and metastatic tissues with high expression of MDM2 and P53 have shortened survival. The proliferation inhibition of APG-115 on p53 wild-type gastric cancer cells of AGS and MKN45 was concentration and time dependent. APG-115 induced apoptosis in gastric cancer cells. APG-115 can induced cell-cycle arrest in G1/G0 phase in the p53 wild-type of gastric cancer cells. APG-115 exhibited potent antitumor activity against established human gastric cancer xenografts. Conclusions: APG-115 can inhibitor tumor growth in p53 wild-type gastric cancer cells by inducing apoptosis and cell cycle arrest both in vitro and vivo. APG-115 can serve as an effective and precise therapeutic strategy for gastric cancer. Citation Format: Lin Zhang, Luo Qiuyun, Yan Xianglei, Xueping Wan, Luping Yuan, Yuxing Zhang, Suna Zhou, Wentao Pan, Mengxian Pan, Miaozhen Qiu, Shijuan Mai, Dajun Yang. A novel small molecule inhibitor of MDM2-p53 (APG-115) has antitumor activity in gastric adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2061.

High α B-crystallin and p53 co-expression is associated with poor prognosis in ovarian cancer.

Objectives: The present study investigated the correlation between α B-crystallin (CRYAB, HSPB5) and p53 expression in ovarian cancer and further analyzed the relationship between their expression and clinicopathology and the prognostic value of their co-expression in ovarian cancer. Methods: CRYAB and p53 expression was assessed using immunohistochemistry on ovarian cancer tumor tissues from 103 cases and validated in an independent group of 103 ovarian cancer patients. Results: High CRYAB and p53 expression rates in ovarian cancer tissues were 61.17% (63/103) and 57.28% (59/103), respectively, and their expression was positively correlated (r = 0.525, P=0.000). High CRYAB expression was significantly correlated with tumor size (P=0.028), lymph node metastasis (P=0.000), distant metastasis (P=0.005), tumor node metastasis (TNM) stage (P=0.002), and survival (P=0.000), while high p53 expression was significantly correlated with tumor size (P=0.006), pathological grade (P=0.023), lymph node metastasis (P=0.001), and survival (P=0.000). Further studies found that the high CRYAB and p53 co-expression was also significantly correlated with pathological grade (P=0.024), lymph node metastasis (P=0.000), Distant metastasis (P=0.015), TNM stage (P=0.013), and survival (P=0.000). High expression of either CRYAB or p53 and high co-expression of CRYAB and p53 were significantly correlated with poor disease-free survival (DFS) and overall survival (OS), respectively (P<0.05). Patients with high CRYAB and p53 co-expression had the worst prognoses among the groups. In addition, multivariate Cox regression models showed that high expression of either CRYAB or p53 and high co-expression of CRYAB and p53 were independent prognostic factors for DFS and OS (P<0.05). Moreover, the positive correlation and prognostic value of CRYAB and p53 expression were verified in another independent dataset. Conclusions: We demonstrated that patients with high CRYAB and p53 co-expression in ovarian cancer have significantly increased risks of recurrence, metastasis, and death compared with other patients. Therefore, more frequent follow-up of patients with high CRYAB and p53 co-expression is required. Our results also suggest that combination therapy with CRYAB inhibitors and p53 blockers may benefit future treatment of ovarian cancer patients with high co-expression of CRYAB and p53.

Patterns of Early p21 Dynamics Determine Proliferation-Senescence Cell Fate after Chemotherapy

Chemotherapy is designed to induce cell death. However, at non-lethal doses, cancer cells can choose to remain proliferative or become senescent. The slow development of senescence makes studying this decision challenging. Here, by analyzing single-cell p21 dynamics before, during, and days after drug treatment, we link three distinct patterns of early p21 dynamics to final cell fate. Surprisingly, while high p21 expression is classically associated with senescence, we find the opposite at early times during drug treatment: most senescence-fated cells express much lower p21 levels than proliferation-fated cells. We demonstrate that these dynamics lead to a p21 "Goldilocks zone" for proliferation, in which modest increases of p21 expression can lead to an undesirable increase of cancer cell proliferation. Our study identifies a counter-intuitive role for early p21 dynamics in the cell-fate decision and pinpoints a source of proliferative cancer cells that can emerge after exposure to non-lethal doses of chemotherapy.

Therapeutic targeting of mutant p53 in pediatric acute lymphoblastic leukemia.

Alterations of the tumor suppressor gene TP53 are found in different cancers, in particular in carcinomas of adults. In pediatric acute lymphoblastic leukemia (ALL), TP53 mutations are infrequent but enriched at relapse. As in most cancers, mainly DNA-binding domain missense mutations are found, resulting in accumulation of mutant p53, poor therapy response, and inferior outcome. Different strategies to target mutant p53 have been developed including reactivation of p53’s wildtype function by the small molecule APR-246. We investigated TP53 mutations in cell lines and 62 B-cell precursor ALL samples and evaluated the activity of APR-246 in TP53-mutated or wildtype ALL. We identified cases with TP53 missense mutations, high (mutant) p53 expression and insensitivity to the DNA-damaging agent doxorubicin. In TP53-mutated ALL, APR-246 induced apoptosis showing strong anti-leukemia activity. APR-246 restored mutant p53 to its wildtype conformation, leading to pathway activation with induction of transcriptional targets and re-sensitization to genotoxic therapy in vitro and in vivo. In addition, induction of oxidative stress contributed to APR-246-mediated cell death. In a preclinical model of patient-derived TP53-mutant ALL, APR-246 reduced leukemia burden and synergized strongly with the genotoxic agent doxorubicin, leading to superior leukemia-free survival in vivo. Thus, targeting mutant p53 by APR-246, restoring its tumor suppressive function, seems to be an effective therapeutic strategy for this high-risk group of TP53-mutant ALL.

Prognostic value of mutant p53, Ki-67, and TTF-1 and their correlation with EGFR mutation in patients with non-small cell lung cancer.

The clinical characteristics of non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutation have been well studied. However, the correlation of EGFR mutation with mutant p53, Ki-67, and thyroid transcription factor 1 (TTF-1) and their prognostic value remain indistinct. Clinical and pathological characteristics and overall survival were analysed retrospectively in 523 surgically resected NSCLC patients. The expression levels of p53, Ki-67, and TTF-1 protein were detected by immunohistochemistry, and an amplification refractory mutation system was used to access the status of EGFR mutations. Of 523 patients with surgically resected NSCLC, 210 patients (38.4%) harboured EGFR mutations. Compared to the EGFR wild-type lung cancer, mutated EGFR harboured significantly increased mutant p53-positive or TTF-1-positive tumors (P<0.001 and<0.001, respectively). Former or current smokers, pathological stage and mutant p53-or TTF-1-positive status were independent predictors of EGFR mutation (P=0.001, 0.014, 0.014 and <0.001, respectively). Patients with p53 under expression had significantly better overall survival in the whole cohort and wild-type EGFR cohort (P=0.0010 and 0.0020, respectively) as well as in Ki-67-negative and TTF-1-positive patients (P<0.0001 and 0.0009, and P<0.0001 and 0.0004, respectively). Interestingly, in patients harbouring EGFR mutations, p53-under expression and Ki-67-negative cases still had better survival than positive cases, whereas there was no obvious difference between TTF-1-negative and TTF-1-positive cases (P=0.0198, 0.0068 and 0.3684, respectively). Finally, in NSCLC patients with wild-type EGFR, positive Ki-67 expression was the independent predictor for the worst survival (P=0.022). The expression levels of mutant p53, Ki-67, and TTF-1 were correlated with EGFR mutation. High expression of mutant p53 and Ki-67 correlated with poor survival in the entire cohort, EGFR mutation or wild-type cohort. In addition, Ki-67 might have an impact on the prognosis for patients with NSCLC with wild-type EGFR.

Predictors of an Invasive Breast Cancer Recurrence after DCIS: A Systematic Review and Meta-analyses.

We performed a systematic review with meta-analyses to summarize current knowledge on prognostic factors for invasive disease after a diagnosis of ductal carcinoma in situ (DCIS). Eligible studies assessed risk of invasive recurrence in women primarily diagnosed and treated for DCIS and included at least 10 ipsilateral-invasive breast cancer events and 1 year of follow-up. Quality in Prognosis Studies tool was used for risk of bias assessment. Meta-analyses were performed to estimate the average effect size of the prognostic factors. Of 1,781 articles reviewed, 40 articles met the inclusion criteria. Highest risk of bias was attributable to insufficient handling of confounders and poorly described study groups. Six prognostic factors were statistically significant in the meta-analyses: African-American race [pooled estimate (ES), 1.43; 95% confidence interval (CI), 1.15-1.79], premenopausal status (ES, 1.59; 95% CI, 1.20-2.11), detection by palpation (ES, 1.84; 95% CI, 1.47-2.29), involved margins (ES, 1.63; 95% CI, 1.14-2.32), high histologic grade (ES, 1.36; 95% CI, 1.04-1.77), and high p16 expression (ES, 1.51; 95% CI, 1.04-2.19). Six prognostic factors associated with invasive recurrence were identified, whereas many other factors need confirmation in well-designed studies on large patient numbers. Furthermore, we identified frequently occurring biases in studies on invasive recurrence after DCIS. Avoiding these common methodological pitfalls can improve future study designs.

The prognostic significance of p63 cytoplasmic expression in colorectal cancer. An immunohistochemical study.

Objectives:To evaluate p63 expression pattern in Saudi colorectal cancer (CRC) patients and correlate that with clinicopathological parameters and its role in carcinogenesis and prognosis.Methods:Archival tumor samples were analyzed by immunohistochemistry for p63 expression in 324 consecutive Saudi patients diagnosed with CRC between January 2006 and December 2017 at the Pathology Department of a tertiary care Hospital, Madinah, Saudi Arabia.Results:P63 over-expression was absent in normal mucosa, while 12.5% cases of adenoma showed its over-expression. In CRC, p63 expression was high in 24.1% of cases. There were no significant correlations between p63 expression and gender, tumor location, tumor size, and tumor histologic differentiation. However, high p63 expression revealed a significant correlation with age (p=0.035), tumor type (p=0.004), American Joint Committee on Cancer stage (p=0.046), lymph node metastasis (p=0.006), lymphovascular invasion (p=0.006), distant metastasis (p=0.049) high Ki67 expression (p=0.000) and K-ras expression (p=0.002). The Kaplan-Meier analysis revealed a shorter period of survival with p63 over-expression (p<0.001). The Cox-regression model analysis showed that p63 over-expression was an independent prognostic marker in CRC (p=0.000).Conclusion:P63 expression increased from normal to adenoma to carcinoma sequence. Moreover, p63 cytoplasmic expression seems to be related to high Ki67 indexing, K-ras expression, advanced tumor stage and poor clinical outcome of CRC. These findings suggest a significant role of cytoplasmic p63 expression in tumor progression and prognosis.