Przemyslaw Bozko

More than four decades after its discovery, p53 remains a central regulator of cellular homeostasis and one of the most extensively studied proteins in cancer biology

Cervical carcinoma is predominantly driven by high-risk human papillomavirus (HPV) infection, in which functional inactivation of p53 occurs mainly through viral oncoproteins rather than mutations in the TP53 gene. This raises questions concerning the prognostic relevance of TP53 gene status and p53 protein levels in this tumor type. This study aimed to systematically evaluate the prognostic significance of TP53 mutation status, p53 protein abundance, and selected downstream p53-regulated proteins in cervical carcinoma, with particular focus on tumors carrying wild-type TP53. Clinical and proteomic data from 162 cervical carcinoma patients were retrieved from The Cancer Genome Atlas (TCGA). Protein levels (p53, BAX, p21/CDKN1A, and TIGAR) were assessed using reverse-phase protein array (RPPA) data. Survival analyses were performed using Kaplan–Meier estimates with log-rank testing after stratification into quartile-based expression groups. The vast majority of tumors (~93%) harbored wild-type TP53, and the TP53 mutation status showed no association with patient survival. In tumors with wild-type TP53, p53 protein levels did not significantly correlate with overall survival, indicating a limited prognostic value. In contrast, elevated levels of the pro-apoptotic protein BAX showed a clear tendency to be associated with poorer overall and progression-free survival, suggesting BAX as a potential prognostic marker in this specific molecular context. The expression of p21/CDKN1A showed no prognostic relevance, while high TIGAR levels displayed a slight trend toward poorer survival, although without reaching statistical significance. In summary, in HPV-driven cervical carcinoma, neither the TP53 mutation status nor the p53 protein abundance reliably predict patient outcome. Instead, selected downstream effectors of p53 signaling—particularly BAX—may provide more informative prognostic insights in tumors retaining wild-type TP53. These findings highlight the importance of assessing functional outputs of p53 signaling rather than the p53 status alone in this disease context.

Pancreatic adenocarcinoma is one of the most aggressive types of cancer. Among different mechanisms generally believed to be important for the development of cancer, aberrant regulation of the p53 protein is a well-known and common feature for many cancer entities. Our work aims to analyze the impact of p53 deregulation and proteins encoded by p53 target genes on the survival of patients suffering from pancreatic adenocarcinoma. We, therefore, focused on the analysis of the selected collective for the TP53 mutation status, the p53 protein level, their correlation, and possible impacts on the prognosis/survival. We compared and analyzed a set of 123 patients. We have extracted information regarding the TP53 mutation status, p53 protein levels, the level of proteins encoded by prominent p53 target genes, and information on the overall survival. Survival analyses were displayed by Kaplan–Meier plots, using the log-rank test, in order to check for statistical significance. Protein levels were compared using the Mann–Whitney Test. We did not find any statistically significant correlation between the TP53 mutation status and the survival of the patients. Moreover, we have not found any significant correlation between the protein amount of prominent p53 target genes and the patients’ survival. However, we see a significant correlation between the p53 protein level in cancer samples and the overall survival of pancreatic adenocarcinoma patients: patients having tumors with a p53 protein level within the upper quartile of all measured cases show a significantly reduced survival compared to the rest of the patients. Thus, in pancreatic adenocarcinoma, the p53 protein level is a relevant marker for prognosis, and cancers having a high p53 protein amount show a shortened patients’ survival. In contrast, for this cancer entity, the TP53 mutation status or the protein amount of prominent p53 target genes on their own seems not to have a significant impact on survival.

Background: Ovarian cancer is one of the most aggressive types of gynecologic cancers. Many patients have a relapse within two years after diagnosis and subsequent therapy. Among different genetic changes generally believed to be important for the development of cancer, TP53 is the most common mutation in the case of ovarian tumors. Objective: Our work aims to compare the outcomes of different comparisons based on the overall survival of ovarian cancer patients, determination of TP53 status, and amount of p53 protein in tumor tissues. Methods: We analyzed and compared a collective of 436 ovarian patient’s data. Extracted data include TP53 mutation status, p53 protein level, and information on the overall survival. Values for p53 protein level in dependence of TP53 mutation status were compared using the Independent-Samples t-Test. Survival analyses were displayed by Kaplan-Meier plots, using the log-rank test to check for statistical significance. Results: We have not found any statistically significant correlations between determination of TP53 status, amount of p53 protein in tumor tissues, and overall survival of ovarian cancer patients. Conclusion: In ovarian tumors both determination of TP53 status as well as p53 protein amount has only limited diagnostic importance.

Background: Cholangiocarcinoma (CCA) is the second most common hepatobiliary cancer and associated with a poor prognosis. Only one-third of CCA cases are diagnosed at operable stages. However, a high rate of relapse has been observed postoperatively. Besides screening for operable individuals, efficacious therapeutic for recurrent and advanced CCA is urgently needed. The treatment outcome of available therapeutics is important to clarify clinical indication and facilitate the development of treatment strategies. Objective: This review aims to compare the treatment outcome of different therapeutics based on both overall survival and progression-free survival. Methods: Over one hundred peer-reviewed articles were examined. We compared the treatment outcome between different treatment methods, including tumor resection with or without postoperative systematic therapy, chemotherapies including FOFLOX, and targeted therapies, such as IDH1, K-RAS, and FGFR inhibitors. Notably, the scientific basis and outcome of available treatment methods were compared with the standard first-line therapy. Results: CCAs at early stages should firstly undergo tumor resection surgery, followed by postoperative treatment with Capecitabine. Chemotherapy can be considered as a preoperative option for unresectable CCAs. Inoperable CCAs with genetic aberrances like FGFR alterations, IDH1, and KRAS mutations should be considered with targeted therapies. Fluoropyrimidine prodrug (S-1)/Gemcitabine/Cisplatin and nab-Paclitaxel/Gemcitabine/Cisplatin show favorable outcome which hints at the triplet regimen to be superior to Gemcitabine/Cisplatin on CCA. The triplet chemotherapeutic should be tested further compared to Gemcitabine/Cisplatin among CCAs without genetic alterations. Gemcitabine plus S-1 was recently suggested as the convenient and equivalent standard first-line for advanced/recurrent biliary tract cancer. Conclusions: This review provides a comparative outcome between novel targeted therapies and currently available therapeutics.

Background and Aim: Cholangiocarcinoma has an unimproved prognosis. Interleukin 6 (IL‐6) has an oncogenic potential in some cancer diseases. However, the role of IL‐6 in cholangiocarcinoma carcinogenesis is not well understood. The current study investigated the role of IL‐6 signaling in cholangiocarcinoma carcinogenesis and efficacy of siltuximab treatment on cholangiocarcinoma in vitro and in vivo.Methods: The expression of IL‐6 was analyzed on human cholangiocarcinoma cell lines and murine and human cholangiocarcinoma tissues, using reverse transcription real‐time polymerase chain reaction and immunohistochemistry. In addition, the effect of anti‐IL‐6 chimeric monoclonal antibody, siltuximab, was investigated in vitro by proliferation, migration, and two‐dimensional and three‐dimensional invasion assays and in vivo by xenograft mouse model. Western blot was applied to study the molecular alteration.Results: Our result shows high expression of IL‐6 in human cholangiocarcinoma cells, and IL‐6 stimulants enhance cholangiocarcinoma cell proliferation. In addition, murine and human cholangiocarcinoma tissues express significantly higher levels of IL‐6, compared with adjacent non‐tumor tissues. On the cholangiocarcinoma engineered mouse model, IL‐6 level is associated with tumor volume. Taken together, our data indicate an oncogenic potential of IL‐6 in cholangiocarcinoma carcinogenesis. Siltuximab sufficiently abrogates IL‐6 signaling and inhibits cholangiocarcinoma progression in vitro and in vivo. The results additionally indicate a relative alteration of IL‐6 signaling and its molecular targets, such as STAT3, Wnt/β‐catenin, and mesenchymal markers.Conclusions: Interleukin 6 plays an essential role in cholangiocarcinoma carcinogenesis, and siltuximab has the potential to be considered as a new treatment option for cholangiocarcinoma patients.

Background: Hepatocellular carcinoma (HCC) represents a major health burden with limited curative treatment options. There is a substantial unmet need to develop innovative approaches to impact the progression of advanced HCC. Haprolid is a novel natural component isolated from myxobacteria. Haprolid has been reported as a potent selective cytotoxin against a panel of tumor cells in recent studies including HCC cells. The aims of this study are to evaluate the antitumor effect of haprolid in HCC and to understand its underlying molecular mechanisms. Methods: The efficacy of haprolid was evaluated in human HCC cell lines (Huh-7, Hep3B and HepG2) and xenograft tumors (NMRI-Foxn1^nu mice with injection of Hep3B cells). Cytotoxic activity of haprolid was determined by the WST-1 and crystal violet assay. Wound healing, transwell and tumorsphere assays were performed to investigate migration and invasion of HCC cells. Apoptosis and cell-cycle distribution were measured by flow cytometry. The effects of haprolid on the Rb/E2F and Akt/mTOR pathway were examined by immunoblotting and immunohistochemistry. Results: haprolid treatment significantly inhibited cell proliferation, migration and invasion in vitro. The epithelial–mesenchymal transition (EMT) was impaired by haprolid treatment and the expression level of N-cadherin, vimentin and Snail was downregulated. Moreover, growth of HCC cells in vitro was suppressed by inhibition of G1/S transition, and partially by induction of apoptosis. The drug induced downregulation of cell cycle regulatory proteins cyclin A, cyclin B and CDK2 and induced upregulation of p21 and p27. Further evidence showed that these effects of haprolid were associated with Rb/E2F downregulation and Akt/mTOR inhibition. Finally, in vivo nude mice experiments demonstrated significant inhibition of tumor growth upon haprolid treatment. Conclusion: Our results show that haprolid inhibits the growth of HCC through dual inhibition of Rb/E2F and Akt/mTOR pathways. Therefore, haprolid might be considered as a new and promising candidate for the palliative therapy of HCC.