Expression of the Long Noncoding RNA DINO in Human Papillomavirus-Positive Cervical Cancer Cells Reactivates the Dormant TP53 Tumor Suppressor through ATM/CHK2 Signaling.
人乳头瘤病毒阳性宫颈癌细胞中长链非编码 RNA DINO 的表达通过 ATM/CHK2 信号重新激活休眠的 TP53 肿瘤抑制因子。
- 作者列表："Sharma S","Munger K
:Tumor cells overcome the cytostatic and cytotoxic restraints of TP53 tumor suppressor signaling through a variety of mechanisms. High-risk human papillomavirus (HPV)-positive tumor cells retain wild-type TP53 because the HPV E6/UBE3A ubiquitin ligase complex targets TP53 for proteasomal degradation. While restoration of TP53 in tumor cells holds great promise for cancer therapy, attempts to functionally restore the dormant TP53 tumor suppressor in HPV-positive cancer cells by inhibiting the HPV E6/UBE3A ubiquitin ligase complex have not yet been successful. The damage-induced long noncoding RNA, DINO (DINOL), is a TP53 transcriptional target that has been reported to bind to and stabilize TP53, thereby amplifying TP53 signaling. We show that HPV-positive cervical carcinoma cells contain low levels of DINO because of HPV E6/UBE3A-mediated TP53 degradation. Acute DINO expression overrides HPV16 E6/UBE3A-mediated TP53 degradation, causing TP53 stabilization and increased expression of TP53 transcriptional target genes. This causes a marked sensitization to chemotherapy agents and renders cells vulnerable to metabolic stress. Acute DINO expression in HPV-positive cervical cancer cells induces hallmarks of DNA damage response signaling, and TP53 activation involves ATM/CHK2 signaling. DINO upregulation in response to DNA damage is independent of ATM/CHK2 and can occur in cancer cells that express mutant TP53.IMPORTANCE Functional restoration of the TP53 tumor suppressor holds great promise for anticancer therapy. Current strategies are focused on modulating TP53 regulatory proteins. Long noncoding RNAs (lncRNAs) have emerged as important regulators of TP53 as well as modulators of downstream tumor-suppressive transcriptional responses. Unlike many other cancer types, human papillomavirus (HPV)-positive cancer cells retain wild-type TP53 that is rendered dysfunctional by the viral E6 protein. We show that acute expression of the damage-induced long noncoding RNA, DINO, a known TP53 transcriptional target and functional modulator, causes TP53 reactivation in HPV-positive cervical cancer cells. This causes increased vulnerability to standard chemotherapeutics as well as biguanide compounds that cause metabolic stress. Hence, strategies that target DINO may be useful for restoring TP53 tumor suppressor activity in HPV-positive cancers and other tumor types that retain wild-type TP53.
: 肿瘤细胞通过多种机制克服 TP53 肿瘤抑制信号的细胞抑制和细胞毒性限制。高危型人乳头瘤病毒 (HPV) 阳性肿瘤细胞保留野生型 TP53，因为 HPV E6/UBE3A 泛素连接酶复合物靶向 TP53 进行蛋白酶体降解。虽然肿瘤细胞中 TP53 的恢复为癌症治疗带来了巨大的希望,通过抑制 HPV E6/UBE3A 泛素连接酶复合物在功能上恢复 HPV 阳性癌细胞中休眠的 TP53 肿瘤抑制因子的尝试尚未成功。损伤诱导的长链非编码 RNA DINO (DINOL) 是 TP53 转录靶点，据报道可结合并稳定 TP53，从而扩增 TP53 信号。我们发现，由于 HPV E6/UBE3A-mediated TP53 的降解，HPV 阳性的宫颈癌细胞中含有低水平的 DINO。急性 DINO 表达覆盖 HPV16 E6/UBE3A-mediated TP53 降解，引起 TP53 稳定和 TP53 转录靶基因表达增加。这导致对化疗药物的显著致敏，并使细胞容易受到代谢应激。HPV 阳性宫颈癌细胞中的急性 DINO 表达诱导 DNA 损伤反应信号的标志，TP53 激活涉及 ATM/CHK2 信号。DINO 对 DNA 损伤的反应上调独立于 ATM/CHK2，可以发生在表达突变型 TP53 重要性的癌细胞中，TP53 肿瘤抑制因子的功能恢复为抗癌治疗带来巨大希望。目前的策略集中在调节 TP53 调控蛋白。长链非编码 rna (lncRNAs) 已经成为 TP53 的重要调控因子以及下游肿瘤抑制转录反应的调节剂。与许多其他癌症类型不同，人乳头瘤病毒 (HPV) 阳性癌细胞保留野生型 TP53，病毒 E6 蛋白使其功能失调。我们发现损伤诱导的长链非编码 RNA DINO 的急性表达，DINO 是一种已知的 TP53 转录靶点和功能调节剂，在 HPV 阳性宫颈癌细胞中引起 TP53 再激活。这导致标准化疗药物以及引起代谢应激的双胍类化合物的脆弱性增加。因此，靶向 DINO 的策略可能有助于恢复 HPV 阳性癌症和其他保留野生型 TP53 的肿瘤类型中的 TP53 肿瘤抑制活性。
METHODS:STUDY OBJECTIVE:To evaluate the differences in perioperative outcomes and immediate complication rates between laparoscopic myomectomy for submucous myomas and laparoscopic myomectomy for myomas in other locations. DESIGN:Retrospective cohort study. SETTING:University-affiliated hospital in London. PATIENTS:A total of 350 patients with symptomatic uterine myomas underwent laparoscopic myomectomy. Thirty-three of these were performed for submucous myomas (group 1), and 317 were for myomas in other uterine locations (group 2). INTERVENTIONS:Analysis of prospectively collected data on patient demographics, myoma characteristics, perioperative outcomes, and immediate complications. MEASUREMENTS AND MAIN RESULTS:Patient demographics, including age, body mass index, and parity, were similar in the 2 groups. No significant differences in myoma characteristics were seen between groups 1 and 2, including the mean dimension of largest myoma (7.1 vs 7.8 cm, respectively; p = .35), mean number of myomas removed (3.8 vs 4.1; p = .665), and mean mass of myomas removed (142.0 g vs 227.3 g; p = .186). There were also no significant between-group differences in any perioperative outcomes, including mean blood loss (226.8 mL vs 266.4 mL; p = .373), duration of surgery (103 minutes vs 113 minutes; p = .264), and duration of hospital stay (1.4 days vs 1.7 days; p = .057). No complications arose from laparoscopic resection of submucous myomas. CONCLUSION:Laparoscopic myomectomy for submucous myomas has similar perioperative outcomes and immediate complications as laparoscopic myomectomy for other myomas and can be considered for large or type 2 submucous myomas.
METHODS:INTRODUCTION:Laparoscopic myomectomy can be difficult when fibroids are large and numerous. This may result in extensive intraoperative bleeding and the need for a conversion to a laparotomy. Medical pretreatment prior to surgery might reduce these risks by decreasing fibroid size and vascularization of the fibroid. We compared pretreatment with ulipristal acetate (UPA) vs gonadotropin-releasing hormone agonists (GnRHa) prior to laparoscopic myomectomy on several intra- and postoperative outcomes. MATERIAL AND METHODS:We performed a non-inferiority double-blind randomized controlled trial in nine hospitals in the Netherlands. Women were randomized between daily oral UPA for 12 weeks and single placebo injection or single intramuscular injection with leuprolide acetate and daily placebo tablets for 12 weeks. The primary outcome was intraoperative blood loss. Secondary outcomes were reduction of fibroid volume, suturing time, total surgery time and surgical ease. RESULTS:Thirty women received UPA and 25 women leuprolide acetate. Non-inferiority of UPA regarding intraoperative blood loss was not demonstrated. When pretreated with UPA, median intraoperative blood loss was statistically significantly higher (525 mL [348-1025] vs 280 mL[100-500]; P = 0.011) and suturing time of the first fibroid was statistically significantly longer (40 minutes [28-48] vs 22 minutes [14-33]; P = 0.003) compared with GnRHa. Pretreatment with UPA showed smaller reduction in fibroid volume preoperatively compared with GnRHa (-7.2% [-35.5 to 54.1] vs -38.4% [-71.5 to -19.3]; P = 0.001). Laparoscopic myomectomies in women pretreated with UPA were subjectively judged more difficult than in women pretreated with GnRHa. CONCLUSIONS:Non-inferiority of UPA in terms of intraoperative blood loss could not be established, possibly due to the preliminary termination of the study. Pretreatment with GnRHa was more favorable than UPA in terms of fibroid volume reduction, intraoperative blood loss, hemoglobin drop directly postoperatively, suturing time of the first fibroid and several subjective surgical ease parameters.
METHODS:AIMS:Hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome is caused by germline mutations in the Fumarate hydratase (FH) gene. In young women, the syndrome often presents with symptomatic uterine leiomyomas, leading to myomectomy or hysterectomy. In this study, we aimed to investigate the incidence and mutational profiles of FH-negative leiomyomas from young patients, thus allowing for early identification and triage of syndromic patients for surveillance. METHODS AND RESULTS:We evaluated 153 cases of uterine leiomyomas from women aged up to 30 years for loss of FH expression by tissue microarray (TMA)-based immunohistochemical staining. Mutational analysis of tumours with loss of FH was carried out by polymerase chain reaction (PCR) amplification of 10 exons within the FH gene and subsequent Sanger sequencing. The status of promoter methylation was assessed by bisulphite sequencing. Loss of FH protein expression was detected in seven (4.6%) of 153 tested uterine leiomyomas from young patients. All FH-negative leiomyomas displayed staghorn vasculature and fibrillary/neurophil-like cytoplasm. We found that six (86%) of seven FH-negative tumours detected by immunohistochemistry harboured FH mutations, 50% of which contained germline mutations. In particular, the germline mutational rate in FH gene was 2.0% (three of 153 cases). Bisulphite sequencing analysis failed to detect promoter methylation in any of the seven tumours. CONCLUSION:Our study showed a relatively high rate of FH germline mutation in FH-negative uterine leiomyomas from patients aged up to 30 years. While genetic mutations confer protein expression loss, epigenetic regulation of the FH gene appears to be unrelated to this phenotype.