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Introduction: Adrenocortical carcinoma is a rare malignancy that typically presents with advanced features and carries a poor prognosis. Complete surgical resection offers patients the best survival outcomes, but this is not always achievable and many require additional therapy for advanced features. Some literature has explored the role of chemotherapy and radiation, but little has been conducted to explore the effects of multimodal therapy. Methods: We retrospectively reviewed the National Cancer Database for adults with primary nonmetastatic adrenocortical carcinoma (ACC) who underwent either partial or radical adrenalectomy. Excluded patients included those with metastatic disease and those with primary tumor >30 cm. Patients were categorized based on adjuvant treatment; chemotherapy, radiation therapy (RT), RT + chemotherapy, or no adjuvant therapy. Overall survival (OS) was compared using survival curves, log rank tests, and multivariate survival analysis. Results: We identified 1644 patients with localized ACC treated with adrenalectomy. The median tumor size was 10.6 cm. A total of 278 patients had positive margin status (R1), and 416 patients had nodal (pN+) disease. Out of all patients, a minority (39.4%) received adjuvant therapy, which was most commonly given as chemotherapy only. Statistically significant increase in OS was noted with the use of RT + chemotherapy in the node-negative, margins-positive (pN0/pNx; R1) subgroup versus patients who did not receive adjuvant therapy (5-year OS 60.5% and 28.2%, respectively [P = 0.002]). This held true on multivariate analysis with significant improvement in OS in the pN0/pNx; R1 population with RT + chemotherapy compared to those who received no treatment (hazard ratio: 0.40 [95% confidence interval: 0.2-0.9], P = 0.02). Conclusions: Our findings support the use of adjuvant chemotherapy plus RT in patients with positive surgical margins and no nodal disease. Additional studies are required to confirm these findings, clarify the objective benefit of multimodal therapy, and to determine the optimal chemotherapy/RT combination.
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Mitochondrial mRNAs in Trypanosoma brucei undergo extensive insertion and deletion of uridylates that are catalyzed by the RNA editing core complex (RECC) and directed by hundreds of small guide RNAs (gRNAs) that base pair with mRNA. RECC is largely RNA-free, and accessory mitochondrial RNA-binding complex 1 (MRB1) variants serve as scaffolds for the assembly of mRNA-gRNA hybrids and RECC. However, the molecular steps that create higher-order holoenzymes ("editosomes") are unknown. Previously, we identified an RNA editing helicase 2-associated subcomplex (REH2C) and showed that REH2 binds RNA. Here we showed that REH2C is an mRNA-associated ribonucleoprotein (mRNP) subcomplex with editing substrates, intermediates, and products. We isolated this mRNP from mitochondria lacking gRNA-bound RNP (gRNP) subcomplexes and identified REH2-associated cofactors 1 and 2 ((H2)F1 and (H2)F2). (H2)F1 is an octa-zinc finger protein required for mRNP-gRNP docking, pre-mRNA and RECC loading, and RNP formation with a short synthetic RNA duplex. REH2 and other eukaryotic DEAH/RHA-type helicases share a conserved regulatory C-terminal domain cluster that includes an oligonucleotide-binding fold. Recombinant REH2 and (H2)F1 constructs associate in a purified complex in vitro. We propose a model of stepwise editosome assembly that entails controlled docking of mRNP and gRNP modules via specific base pairing between their respective mRNA and gRNA cargo and regulatory REH2 and (H2)F1 subunits of the novel mRNP that may control specificity checkpoints in the editing pathway.