An applied anatomical study of bronchial artery.

The aim of this study was to reveal the external features of the bronchial artery (BA) system, so as to provide morphological basis for clinic. The BAs in 48 adult cadavers were dissected and analyzed. The number of BAs in 48 cases was 118. The incidence of BA arising from thoracic aorta, right posterior intercostal artery, and right subclavian artery was 69.49, 27.12, and 3.39%, respectively. The origin of BAs in individual specimen might be single, two, or all of them, respectively. According to the different origin and/or origins of BAs, it could be divided into five categories. As for the course of BAs, in this study, all the left BAs arising from thoracic aorta passed forward around the left side of esophagus and then entered left pulmonary hilum; most (n = 15) of the right BAs arising from thoracic aorta passed forward around the left side of esophagus and then entered right pulmonary hilum; a few (n = 8) of the right BAs arising from thoracic passed forward the right side of esophagus and bronchus and then entered right pulmonary hilum. Besides, in our group, the special courses were that right intercostal-bronchial trunk (RICBT) arising from thoracic aorta passed between vertebra and esophagus and gave off BA which curved forward around the right side of esophagus and then entered right pulmonary hilum, common bronchial trunk (CBT) arising from thoracic aorta passed forward around the left side of esophagus laying anterior to bronchus or posterior to bronchus, then dividing into a left and a right BAs entering right and left pulmonary hilum, respectively. In 4 cadavers, the RICBT gave off the radiculomedullary artery and BA in turn, so radiculomedullary artery has the same origin with BA. Of all BAs, the mean diameter of right posterior intercostal artery, CBT, left BA, and right BA was 2.17 ± 0.84, 1.79 ± 0.57, 1.44 ± 0.50, and 1.39 ± 0.38 mm, respectively. The information gained from this study will be of value in clinic application.

Inhibition of epithelial-to-mesenchymal transition augments antitumor efficacy of nanotherapeutics in pancreatic ductal adenocarcinoma.

Intrinsic drug resistance mechanisms of tumor cells often reduce intracellular drug concentration to suboptimal levels. Epithelial-to-mesenchymal transition (EMT) is a pivotal process in tumor progression and metastasis that confers an aggressive phenotype as well as resistance to chemotherapeutics. Therefore, it is imperative to develop novel strategies and identify new targets to improve the overall efficacy of cancer treatment. We developed SN38 (active metabolite of irinotecan)-assembled glycol chitosan nanoparticles (cSN38) for the treatment of pancreatic ductal adenocarcinoma (PDAC). Furthermore, cSN38 and the TGF-ß1 inhibitor LY364947 formed composite nanoparticles upon self-assembly (cSN38 + LY), which obviated the poor aqueous solubility of LY364947 and enhanced drug sensitivity. The therapeutic efficacy of cSN38 + LY nanotherapeutics was studied in vitro and in vivo using suitable models. The cSN38 nanoparticles exhibited an antitumor effect that was significantly attenuated by TGF-ß-induced EMT. The cellular uptake of SN38 was impeded during EMT, which affected the therapeutic efficacy. The combination of LY364947 and cSN38 markedly enhanced the cellular uptake of SN38, increased cytotoxic effects, and inhibited EMT in PDAC cells in vitro. Furthermore, cSN38 + LY significantly inhibited PDAC xenograft growth in vivo. The cSN38 + LY nanoparticles increased the therapeutic efficacy of cSN38 via repressing the EMT of PDAC cells. Our findings provide a rationale for designing nanoscale therapeutics to combat PDAC.

Deubiquitinating PABPC1 by USP10 upregulates CLK2 translation to promote tumor progression in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is extremely malignant with limited treatment options. Deubiquitinases (DUBs), which cleave ubiquitin on substrates, can regulate tumor progression and are appealing therapeutic targets, but there are few related studies in PDAC. In our study, we screened the expression levels and prognostic value of USP family members based on published databases and selected USP10 as the potential interventional target in PDAC. IHC staining of the PDAC microarray revealed that USP10 expression was an adverse clinical feature of PDAC. USP10 promoted tumor growth both in vivo and in vitro in PDAC. Co-IP experiments revealed that USP10 directly interacts with PABPC1. Deubiquitination assays revealed that USP10 decreased the K27/29-linked ubiquitination level of the RRM2 domain of PABPC1. Deubiquitinated PABPC1 was able to couple more CLK2 mRNA and eIF4G1, which increased the translation efficiency. Replacing PABPC1 with a mutant that could not be ubiquitinated impaired USP10 knock-down-mediated tumor suppression in PDAC. Targeting USP10 significantly delayed the growth of cell-derived xenograft and patient-derived xenograft tumors. Collectively, our study first identified USP10 as the DUB of PABPC1 and provided a rationale for potential therapeutic options for PDAC with high USP10 expression.

SIGLEC15 amplifies immunosuppressive properties of tumor-associated macrophages in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) usually presents infrequent infiltration of T lymphocytes. The known immune-checkpoint inhibitors to date focus on activating T cells and manifest limited effectiveness in PDAC. SIGLEC15 was identified as a novel tumor-associated macrophage (TAM)-related immune-checkpoint in other cancer types, while its immunosuppressive role and clinical significance remained unclear in PDAC. In our study, SIGLEC15 presented immunosuppressive relevance in PDAC via bioinformatic analysis and expressed on TAM and PDAC cells. SIGLEC15+ TAM, rather than SIGLEC15+ PDAC cells or SIGLEC15- TAM, correlated with poor prognosis and immunosuppressive microenvironment in the PDAC microarray cohort. Compared with SIGLEC15- TAM, SIGLEC15+ TAM presented an M2-like phenotype that could be modulated by SIGLEC15 in a tumor cell-dependent manner. In mechanism, SIGLEC15 interacted with PDAC-expressed sialic acid, preferentially α-2, 3 sialic acids, to stimulate SYK phosphorylation in TAM, which further promoted its immunoregulatory cytokines and chemokines production. In vivo, SIGLEC15+ TAM also presented an M2-like phenotype, accelerated tumor growth, and facilitated immunosuppressive microenvironment, which was greatly abolished by SYK inhibitor. Our study highlighted a novel M2-promoting function of SIGLEC15 and strongly suggested SIGLEC15 as a potential immunotherapeutic target for PDAC.