Telomerase expression abrogates rapamycin-induced irreversible growth arrest of uterine fibroid smooth muscle cells

Senescence-associated secretory phenotype (SASP) and uterine fibroids: Association with PD-L1 activation and collagen deposition

Uterine fibroids (or uterine leiomyoma, UFs) are one of the most prevalent benign uterine tumors with high proliferation and collagen synthesis capabilities. UFs are a significant worldwide health issue for women, affecting their physical and financial well-being. Risk factors for UFs include age, racial disparities, obesity, uterine infections, hormonal variation, and lifestyle (i.e., diet, exercise, stress, and smoking). Senescence and its associated secretory phenotypes (SASPs) are among the most salient changes accompanying the aging process. As a result, SASPs are suggested to be one of the major contributors to developing UFs. Interleukin 6 (IL-6), IL-8, IL-1, chemokine ligand 20 (CCL-20), and transforming growth factor-beta (TGF-β) are the most prominent SASPs associated with aging. In addition, different processes contribute to UFs such as collagen deposition and the changes in the immune microenvironment. Programmed death ligand 1 is a major player in the tumor immune microenvironment, which helps tumor cells evade immune attacks. This review focuses on the correlation of SASPs on two axes of tumor progression: immune suppression and collagen deposition. This review opens the door towards more investigations regarding changes in the UF immune microenvironment and age-UFs correlation and thus, a novel targeting approach for UF treatment.

Safety and efficacy of sirolimus in recurrent intravenous leiomyomatosis, pulmonary benign metastatic leiomyomatosis, and leiomyomatosis peritonealis disseminata: a pilot study

BACKGROUND

Intravenous leiomyomatosis (IVL), pulmonary benign metastatic leiomyomatosis (PBML), and leiomyomatosis peritonealis disseminata (LPD) are leiomyomas with special growth patterns and high postoperative recurrence rates. We report the safety and efficacy of a pilot study of sirolimus in the treatment of recurrent IVL, PBML, and recurrent LPD.

METHODS

This was a pilot study to evaluate the safety and efficacy of sirolimus in the treatment of leiomyomatosis (ClinicalTrials.gov identifier NCT03500367) conducted in China. Patients received oral sirolimus 2 mg once a day for a maximum of 60 months or until disease progression, intolerable toxicity, withdrawal of consent, or investigator decision to stop. The primary end point of this study was the objective response rate. Secondary end points included safety and tolerability, disease control rate, and progression-free survival.

RESULTS

A total of 15 patients with leiomyomatosis were included in the study, including five with recurrent IVL, eight with PBML and two with recurrent LPD. The median follow-up time was 15 months (range 6-54 months), nine patients (60%) had treatment-related adverse events (including all levels), and two patients had treatment-related grade 3 or 4 adverse events. The objective response rate was 20.0% (95% CI, 7.1-45.2%), and the disease control rate was 86.7% (95% CI, 62.1-96.3%). Partial response was achieved in three patients. The median response time in the three partial response patients was 33 months (range 29-36 months), and the sustained remission time of these three patients reached 0, 18, and 25 months, respectively.

CONCLUSIONS

Sirolimus was safe and effective in the treatment of recurrent IVL, PBML, and recurrent LPD.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT03500367. Registered on 18 April 2018.

Quantitative assessment of human uterine fibroid xenograft using sequential in vivo bioluminescence imaging

Uterine fibroid is one of the most common solid tumors occurring in reproductive age women. Lack of accurate methods for In vivo quantitative assessment of uterine fibroid progression severely impedes the basic research and drug screen of this disease. To solve this problem, the correlation between bioluminescence imaging (BLI) and initial cell number used to form xenograft was investigated in this study. The results showed that both subcutaneous (SC) and intraperitoneal (IP) D-luciferin administration led to fast increase of bioluminescence signal (BLS) intensity and caused large variation of peak signal intensity of xenografts through the analysis of BLI kinetic curves. We found that a distinct linear stage appeared in xenograft BLI curve for each mouse subjected to IP-injection of D-luciferin. Moreover, a high positive correlation was found between linear slope and the initial number of human uterine fibroid smooth muscle cells (fSMCs) used for xenograft formation. Our research indicates that the slope of linear stage in BLI curve is more appropriate for in vivo quantitative assessment of human uterine fibroid xenograft.

Gene regulatory network underlying the immortalization of epithelial cells

BACKGROUND

Tumorigenic transformation of human epithelial cells in vitro has been described experimentally as the potential result of spontaneous immortalization. This process is characterized by a series of cell-state transitions, in which normal epithelial cells acquire first a senescent state which is later surpassed to attain a mesenchymal stem-like phenotype with a potentially tumorigenic behavior. In this paper we aim to provide a system-level mechanistic explanation to the emergence of these cell types, and to the time-ordered transition patterns that are common to neoplasias of epithelial origin. To this end, we first integrate published functional and well-curated molecular data of the components and interactions that have been found to be involved in such cell states and transitions into a network of 41 molecular components. We then reduce this initial network by removing simple mediators (i.e., linear pathways), and formalize the resulting regulatory core into logical rules that govern the dynamics of each of the network components as a function of the states of its regulators.

RESULTS

Computational dynamic analysis shows that our proposed Gene Regulatory Network model recovers exactly three attractors, each of them defined by a specific gene expression profile that corresponds to the epithelial, senescent, and mesenchymal stem-like cellular phenotypes, respectively. We show that although a mesenchymal stem-like state can be attained even under unperturbed physiological conditions, the likelihood of converging to this state is increased when pro-inflammatory conditions are simulated, providing a systems-level mechanistic explanation for the carcinogenic role of chronic inflammatory conditions observed in the clinic. We also found that the regulatory core yields an epigenetic landscape that restricts temporal patterns of progression between the steady states, such that recovered patterns resemble the time-ordered transitions observed during the spontaneous immortalization of epithelial cells, both in vivo and in vitro.

CONCLUSION

Our study strongly suggests that the in vitro tumorigenic transformation of epithelial cells, which strongly correlates with the patterns observed during the pathological progression of epithelial carcinogenesis in vivo, emerges from underlying regulatory networks involved in epithelial trans-differentiation during development.

Everolimus as an mTOR Inhibitor Suppresses Endometriotic Implants: an Experimental Rat Study

Introduction Mammalian target of rapamycin is a pathway to block apoptosis. Recent studies showed that the activity of mammalian target of rapamycin pathway increases in endometriotic lesions. Aim of the present study was to study the effect of everolimus agent, a rapamycin analog, in an experimental endometriosis model. Materials and Methods Endometriosis established by the autotransplantation of uterine tissue in the peritoneal cavity was confirmed in 24 rats. The animals were then randomly divided into three groups to receive either everolimus (1.5 mg/kg/day, p. o.), anastrozole (0.004 mg/day, p. o.), or normal saline (0.1 mL, i. p.) for 14 days. Endometriotic foci were excised, stained with hematoxylin and eosin, and endometriosis was scored semiquantitatively. In addition, immunohistochemical examination were performed using primary antibodies of vascular endothelial growth factor, CD117, and Bax. Results Both anastrozole and everolimus lowered endometriosis scores. Significant decreases in ovarian follicles were observed following anastrozole treatment but not everolimus treatment. Conclusion Through its apoptosis-promoting effect, everolimus suppressed endometriotic foci without negatively affecting ovarian reserve. These findings support the hypothesis that everolimus merits further study on the way to developing a new endometriosis drug.