Abstract 3839
Background
Multipotent cancer stem cells (CSC) are involved in micro-evolutionary tumor adaptation to therapeutic regimens. Due to their drug-resistance, they represent a promising target for treatment strategies of advanced prostate tumors. Fenofibrate (FF) has recently been pinpointed as a potential metronomic agent that augments the sensitivity of cancer cells to chemotherapeutic drugs. Here, we hypothesized that FF interferes with the drug-resistance of prostate cancer cell populations through the interference with the functions of cancer stem cell-like (SCL) cells.
Methods
Naïve and drug-resistant DU145 cells cultivated in control conditions and in the presence of DCX and/or FF were immunostained against pluripotency markers and analyzed with fluorescent microscopy, fluorescent activated cell sorting (FACS) and image stream.
Results
FACS analyses of naïve and docetaxel (DCX)-resistant DU145 cells revealed minute sub-populations of CD133+/CD44-, CD133+/CD44+ and CD133-/CD44+ SCL cells. SCL fractions were elevated within DCX-treated naïve and DCX-resistant DU145 cell line populations. More prominent increase of SCL-fraction was also observed in naïve, and to lower extent, in drug-resistant DU145 lineages upon combined DCX/FF treatment, which confirms their drug-resistance. CD44+ cells formed the aggregates of round and loosely attached cells, surrounded by morphologically diverse cellular clusters. These SCL cells offspring displayed neoplastic and invasive phenotype similar to that of parental cells; however, they showed increased, P-gp-dependent DCX- but not DCX/FF resistance. Loss of drug-resistance over time of SCL cells offspring was accompanied by induction of their EMT and invasive potential, and combined DCX/FF treatment interfered with this process.
Conclusions
These observations confirm the phenotypic plasticity of SCL cells and its role in the maintenance of prostate cancer cell heterogeneity and drug-resistance. FF can enhance the efficiency of palliative prostate cancer therapies through the interference with the function of cancer stem cells.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Jagiellonian University, Faculty of Biochemistry, Biophysics and Biotechnology.
Funding
National Science Centre Poland.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
1945 - Randomized Phase II Study of Trabectedin/Olaparib Compared to Physician’s Choice in Subjects with Previously Treated Advanced or Recurrent Solid Tumors Harboring DNA Repair Deficiencies.
Presenter: Christoph Heilig
Session: Poster Display session 3
Resources:
Abstract
3021 - Homogenisation of Leftover Surgical Tissue across multiple cancer types: a Feasibility Study (HoLST-F)
Presenter: Lavinia Spain
Session: Poster Display session 3
Resources:
Abstract
2882 - Safety, efficacy, and immune effects of intratumoral tilsotolimod in patients with refractory solid tumors: updated results from ILLUMINATE-101
Presenter: Hani Babiker
Session: Poster Display session 3
Resources:
Abstract
1950 - Phase 1 Dose Escalation of MSC-1, a humanized anti-LIF monoclonal antibody, in patients (pts) with advanced solid tumors: Updated results
Presenter: Erkut Borazanci
Session: Poster Display session 3
Resources:
Abstract
2391 - A phase 1 study of Sym021, an anti-PD-1 antibody (Ab), alone and in combination with Sym022 (anti-LAG-3) or Sym023 (anti-TIM-3)
Presenter: Anna Spreafico
Session: Poster Display session 3
Resources:
Abstract
5692 - FPA150 (B7-H4 antibody) Phase 1 Update in Advanced Solid Tumors: Monotherapy and in Combination with Pembrolizumab
Presenter: Zev Wainberg
Session: Poster Display session 3
Resources:
Abstract
2416 - MG1124, a novel CEACAM1-targeted monoclonal antibody, has therapeutic potential as a combination partner of PD-1 inhibitors in NSCLC patients
Presenter: Eun Hee Lee
Session: Poster Display session 3
Resources:
Abstract
2661 - Tumor stroma targeting and modulation by OMTX705 ADC, a novel and potent immunotherapeutic treatment of solid tumors.
Presenter: Myriam Fabre
Session: Poster Display session 3
Resources:
Abstract
3681 - Durvalumab + monalizumab, mFOLFOX6, and bevacizumab in patients (pts) with metastatic microsatellite-stable colorectal cancer (MSS-CRC)
Presenter: May Cho
Session: Poster Display session 3
Resources:
Abstract
2664 - Phase (Ph) II study of MBG453 + spartalizumab in patients (pts) with non-small cell lung cancer (NSCLC) and melanoma pretreated with anti–PD-1/L1 therapy
Presenter: Nicholas Mach
Session: Poster Display session 3
Resources:
Abstract