Microtentacle Formation in Ovarian Carcinoma

Jocelyn C Reader; Cong Fan; Eleanor Claire-Higgins Ory; Julia Ju; Rachel Lee; Michele I Vitolo; Paige Smith; Sulan Wu; Mc Millan Nicol Ching; Emmanuel B Asiedu; Christopher M Jewell; Gautam G Rao; Amy Fulton; Tonya J Webb; Peixin Yang; Alessandro D Santin; Huang-Chiao Huang; Stuart S Martin; Dana M Roque

doi:10.3390/cancers14030800

Microtentacle Formation in Ovarian Carcinoma

Cancers (Basel). 2022 Feb 4;14(3):800. doi: 10.3390/cancers14030800.

Authors

Jocelyn C Reader^{1

2}, Cong Fan¹, Eleanor Claire-Higgins Ory³, Julia Ju³, Rachel Lee³, Michele I Vitolo⁴, Paige Smith¹, Sulan Wu^{5

6}, Mc Millan Nicol Ching^{1

7

8}, Emmanuel B Asiedu⁹, Christopher M Jewell^{10

11}, Gautam G Rao¹, Amy Fulton^{11

12}, Tonya J Webb⁹, Peixin Yang¹³, Alessandro D Santin¹⁴, Huang-Chiao Huang¹⁰, Stuart S Martin^{4

12}, Dana M Roque¹

Affiliations

¹ Division of Gynecologic Oncology, Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
² Department of Pharmaceutical Sciences, School of Pharmacy and Health Sciences, University of Maryland Eastern Shore, Princess Anne, MD 21853, USA.
³ Department of Physiology, Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
⁴ Department of Pharmacology, Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
⁵ Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH 44074, USA.
⁶ Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
⁷ Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
⁸ Division of Cancer Imaging, Russel H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins Hospital, Baltimore, MD 21287, USA.
⁹ Department of Microbiology and Immunology, Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
¹⁰ Fischell Department of Bioengineering, University of Maryland College Park, College Park, MD 20742, USA.
¹¹ Baltimore Veterans Administration Medical Center, Baltimore, MD 21201, USA.
¹² Department of Pathology, Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
¹³ Department of Obstetrics, Gynecology & Reproductive Sciences and Biochemistry & Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
¹⁴ Division of Gynecologic Oncology, Smilow Cancer Center, Yale University, New Haven, CT 06520, USA.

Abstract

Background: The development of chemoresistance to paclitaxel and carboplatin represents a major therapeutic challenge in ovarian cancer, a disease frequently characterized by malignant ascites and extrapelvic metastasis. Microtentacles (McTNs) are tubulin-based projections observed in detached breast cancer cells. In this study, we investigated whether ovarian cancers exhibit McTNs and characterized McTN biology.

Methods: We used an established lipid-tethering mechanism to suspend and image individual cancer cells. We queried a panel of immortalized serous (OSC) and clear cell (OCCC) cell lines as well as freshly procured ascites and human ovarian surface epithelium (HOSE). We assessed by Western blot β-tubulin isotype, α-tubulin post-translational modifications and actin regulatory proteins in attached/detached states. We studied clustering in suspended conditions. Effects of treatment with microtubule depolymerizing and stabilizing drugs were described.

Results: Among cell lines, up to 30% of cells expressed McTNs. Four McTN morphologies (absent, symmetric-short, symmetric-long, tufted) were observed in immortalized cultures as well as ascites. McTN number/length varied with histology according to metastatic potential. Most OCCC overexpressed class III ß-tubulin. OCCC/OSC cell lines exhibited a trend towards more microtubule-stabilizing post-translational modifications of α-tubulin relative to HOSE. Microtubule depolymerizing drugs decreased the number/length of McTNs, confirming that McTNs are composed of tubulin. Cells that failed to form McTNs demonstrated differential expression of α-tubulin- and actin-regulating proteins relative to cells that form McTNs. Cluster formation is more susceptible to microtubule targeting agents in cells that form McTNs, suggesting a role for McTNs in aggregation.

Conclusions: McTNs likely participate in key aspects of ovarian cancer metastasis. McTNs represent a new therapeutic target for this disease that could refine therapies, including intraperitoneal drug delivery.

Keywords: clear cell carcinoma; epothilone; intraperitoneal chemotherapy; ixabepilone; microtentacle; microtubules; ovarian cancer; paclitaxel; serous carcinoma; taxane.

Abstract

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