Accumulated cytotoxicity of CDK inhibitor dinaciclib with first-line chemotherapy drugs in salivary adenoid cystic carcinoma cells

The Cdk inhibitor dinaciclib as a promising anti-tumorigenic agent in biliary tract cancer

Biliary tract cancer (BTC) is a rare malignancy with rising incidence. The therapeutic options are limited and the overall survival remains poor. Cyclin-dependent kinases, drivers of cell cycle and transcription have numerous biological functions and are known to be dysregulated in numerous tumor entities. Dinaciclib is a selective Cdk1/2/5/9 inhibitor with anti-tumor activity. In the present study, the efficacy of dinaciclib was tested on a comprehensive BTC cell-line model. The results indicate a heterogeneous expression pattern of Cdk1/2/5/9, as well as various differentiation tumor markers in BTC cells. We demonstrated that dinaciclib reduces cell viability, ATP levels, and proliferation rates. Moreover, dinaciclib induces apoptosis via increased caspase 3/7 activity and reduced expression levels of the anti-apoptotic protein Mcl-1 in a concentration- and cell line -dependent manner. 3D cell culture confirms the cytotoxic impact of dinaciclib under more physiologic tumor conditions. Additionally, dinaciclib affects different cell growth regulators like EGFR and STAT3 on gene and protein level, thus decreasing tumor growth. In summary, our study indicates that dinaciclib acts as a promising anti-tumorigenic agent in 2D and 3D in vitro BTC models and thus encourages further investigation.

Cytotoxic effects of targeted agent alone or with chemotherapy in the treatment of adenoid cystic carcinoma: a preclinical study

Adenoid cystic carcinoma (ACC) is a rare malignancy characterized by high incidence of relapse. When relapsing, ACC has an indolent but relentless behaviour, thus leading to a poor long-term prognosis. The treatment of choice of relapsing ACC remains surgery followed by radiotherapy, whenever feasible. Therapeutic weapons are limited to systemic drugs. The most widely used chemotherapy regimen is the combination of cisplatin and doxorubicin, however with low response rate and not long lasting; there is also a lack of alternatives for second line therapies in case of disease progression. Therefore, a more comprehensive strategy aimed at identifying at preclinical level the most promising drugs or combination is clearly needed. In this study, the cytotoxic effects of two standard chemotherapy drugs, cisplatin and doxorubicin, and of five targeted therapy-drugs was tested in vitro, on an h-TERT immortalized ACC cell line, and in vivo, on zebrafish embryos with ACC tumoral cell xenograft. Then, combinations of one standard chemotherapy drug plus one targeted therapy drug were also evaluated, in order to find the best treatment strategy for ACC. Data obtained demonstrated that both vorinostat and olaparib significantly increased the standard chemotherapy cytotoxic effects, suggesting new interesting therapeutic options for ACC.

Expression of apoptotic protease activating factor-1 in adenoid cystic carcinoma of the salivary glands and its clinicopathological relevance

Background/Aim. Apoptotic protease-activating factor-1 (Apaf-1) is a key molecule in the intrinsic or mitochondrial pathway of apoptosis. Some pathological conditions, such as cancer, stroke, and neurodegenerative diseases, are the result of dysregulation in the intrinsic apoptosis pathway. The aim of this study was to analyze the immuno-histochemical expression of Apaf-1 in adenoid cystic carcinoma (ACC) cells of the salivary glands and its correlation with clinicopathological parameters of patients (gender, age, localization, histological type, and overall survival). Methods. Formalin-fixed, paraffin-embedded tissues of ACC of the salivary glands from 50 male and female patients with an average age of 58 years, were used for the study. We used the technique of tissue microarray (TMA blocks). Sections from the TMA mold, 5 ?m thick, were stained with the streptavidin-biotin immunohistochemical technique using primary antibodies specific for Apaf-1 (Leica Biosystems, Newcastle, UK). Stained tissue sections were analyzed by the light microscope (Olympus type BH-2). Based on the data collected, the database was created in SPSS software v. 22.0 (SPSS Inc., Chicago, ILL, USA), which was used for further statistical analysis. The statistical data analysis included methods of descriptive and analytical (inferential) statistics. Results. The results of the immunohistochemical analysis of Apaf-1 expression in the samples of patients with ACC of the salivary glands were compared with the clinicopathological parameters of these patients. The immunohistochemical expression of Apaf-1 showed no statistical significance with regard to the patients? gender (p = 0.552), age (p = 0.106), histological tumor type (p = 0.654), and localization of ACC in the salivary glands (p = 0.486). There was no statistically significant correlation observed between the overall survival of ACC patients and Apaf-1 expression in tumor cells (p = 0.340, Log-Rank test). Conclusion. With regard to ACC, Apaf-1 expression is not in correlation with clinicopathological parameters (gender, age, localization, histological tumor type, outcome of the disease, and overall survival). Therefore, we believe Apaf-1 cannot be regarded as an independent prognostic factor for course and outcome of ACC of the salivary glands.

Dinaciclib, a Bimodal Agent Effective against Endometrial Cancer

Endometrial cancer (EC) is the sixth most prevalent female cancer globally and although high rates of success are achieved when diagnosed at an early stage, the 5-year survival rate for cancers diagnosed at Stages II-IV is below 50%. Improving patient outcomes will necessitate the introduction of novel therapies to the clinic. Pan-cyclin-dependent kinase inhibitors (CDKis) have been explored as therapies for a range of cancers due to their ability to simultaneously target multiple key cellular processes, such as cell cycle progression, transcription, and DNA repair. Few studies, however, have reported on their potential for the treatment of EC. Herein, we examined the effects of the pan-CDKi dinaciclib in primary cells isolated directly from tumors and EC cell lines. Dinaciclib was shown to elicit a bimodal action in EC cell lines, disrupting both cell cycle progression and phosphorylation of the RNA polymerase carboxy terminal domain, with a concomitant reduction in Bcl-2 expression. Furthermore, the therapeutic potential of combining dinaciclib and cisplatin was explored, with the drugs demonstrating synergy at specific doses in Type I and Type II EC cell lines. Together, these results highlight the potential of dinaciclib for use as an effective EC therapy.

Prognosis and management of recurrent and/or metastatic head and neck adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is a rare tumor, usually arising in the salivary gland, accounting for 1% of all head and neck cancers. ACC may have a long-term poor prognosis, as about 40% of radically treated patients will recur locoregionally and up to 60% will develop distant metastasis. Factors influencing risk of recurrence have been well studied, but few data exist about prognostic factors in Recurrent/Metastatic (RM) setting. Moreover, treatment of RM ACC is often a challenge for clinicians, in the context of a rare disease, which may have an indolent clinical behavior or less frequently a quicker growth and with a paucity of available clinical trials. This review critically analyzes pathological and molecular prognostic factors in RM ACC and make an overview on actual therapeutic choices and future direction of therapy. Recognized prognostic factors in RM ACC are the presence and site of distant metastasis (lung vs other), the presence of nodal metastasis and of extranodal extension, skull base recurrence, disease free interval, lymphovascular invasion, solid histotypes and grading of disease, and the presence of mutation of NOTCH1 family, PI3K, and TP53. Due to disappointing results with chemotherapy, new approaches are under study, also on the basis of biomolecular research. Ongoing clinical trials are evaluating treatment targeting MYB and NOTCH1 alterations, immunotherapy or combination of targeted treatments and immune checkpoint inhibitors.