Sex-specific mating pheromones in the nematode Panagrellus redivivus.

Nematodes use an extensive chemical language based on glycosides of the dideoxysugar ascarylose for developmental regulation (dauer formation), male sex attraction, aggregation, and dispersal. However, no examples of a female- or hermaphrodite-specific sex attractant have been identified to date. In this study, we investigated the pheromone system of the gonochoristic sour paste nematode Panagrellus redivivus, which produces sex-specific attractants of the opposite sex. Activity-guided fractionation of the P. redivivus exometabolome revealed that males are strongly attracted to ascr#1 (also known as daumone), an ascaroside previously identified from Caenorhabditis elegans hermaphrodites. Female P. redivivus are repelled by high concentrations of ascr#1 but are specifically attracted to a previously unknown ascaroside that we named dhas#18, a dihydroxy derivative of the known ascr#18 and an ascaroside that features extensive functionalization of the lipid-derived side chain. Targeted profiling of the P. redivivus exometabolome revealed several additional ascarosides that did not induce strong chemotaxis. We show that P. redivivus females, but not males, produce the male-attracting ascr#1, whereas males, but not females, produce the female-attracting dhas#18. These results show that ascaroside biosynthesis in P. redivivus is highly sex-specific. Furthermore, the extensive side chain functionalization in dhas#18, which is reminiscent of polyketide-derived natural products, indicates unanticipated biosynthetic capabilities in nematodes.

Overview, Diagnosis, and Perioperative Systemic Therapy of Upper Tract Urothelial Carcinoma.

Upper tract urothelial carcinoma comprises 5-10% of all urothelial carcinoma cases. This disease tends to have a more aggressive course than its lower urinary tract counterpart, with 60% of patients presenting with invasive disease and 30% of patients presenting with metastatic disease at diagnosis. The diagnostic workup of UTUC involves imaging with CT urogram, urine cytology, and direct visualization and biopsy of suspected lesions via ureteroscopy. Standard treatment of high-grade UTUC involves radical nephroureterectomy (RNU) and excision of the ipsilateral bladder cuff. Both the NCCN and EAU Guidelines include neoadjuvant chemotherapy as a treatment option for select patients with UTUC; however, there are no strict guidelines. Much of the rationale for neoadjuvant chemotherapy is based on extrapolation from data from muscle-invasive bladder cancer, which has demonstrated a 5-year OS benefit of 5-8%. Retrospective studies evaluating the use of NACT in urothelial carcinoma have yielded pathologic objective response rates of 48% in UTUC cohorts. The randomized Phase III POUT study noted a DFS advantage with adjuvant platinum-based chemotherapy, compared with surveillance in UTUC, of 70% vs. 51% at 2 years. Though not the standard of care, multiple studies have explored the use of perioperative immunotherapy or chemoimmunotherapy in the management of invasive urothelial carcinoma. The PURE-02 study explored the use of neoadjuvant pembrolizumab in patients with high-risk UTUC. A small study of 10 patients, it showed no significant signals of activity with neoadjuvant pembrolizumab. Another Phase II study of neoadjuvant ipilimumab and nivolumab in cisplatin-ineligible UTUC yielded more promising findings, with 3/9 patients attaining a pathologic CR and the remaining six pathologically downstaged. The ABACUS trial found a 31% pathologic complete response rate amongst cisplatin-ineligible MIBC patients treated with neoadjuvant atezolizumab. The use of adjuvant immunotherapy has been explored over three phase III trials. The CheckMate-274 trial found a DFS benefit with the addition of one year of adjuvant nivolumab in patients with high-risk urothelial carcinoma. The IMvigor-010 study of adjuvant atezolizumab was a negative study. The AMBASSADOR trial of adjuvant pembrolizumab is pending results. With the FDA approval of erdafitinib in metastatic urothelial carcinoma, similar targets have been explored for use in perioperative use in invasive urothelial carcinoma, as with adjuvant infigratinib in the PROOF-302 trial. As the treatment paradigm for urothelial carcinoma evolves, further prospective studies are needed to expand the perioperative treatment landscape of UTUC.