Citations

Abstract RPA is a critical factor for DNA replication and replication stress response. Surprisingly, we found that chromatin RPA stability is tightly regulated. We report that the GDP/GTP exchange factor DOCK7 acts as a critical replication stress regulator to promote RPA stability on chromatin. DOCK7 is phosphorylated by ATR and then recruited by MDC1 to the chromatin and replication fork during replication stress. DOCK7-mediated Rac1/Cdc42 activation leads to the activation of PAK1, which subsequently phosphorylates RPA1 at S135 and T180 to stabilize chromatin-loaded RPA1 and ensure proper replication stress response. Moreover, DOCK7 is overexpressed in ovarian cancer and depleting DOCK7 sensitizes cancer cells to camptothecin. Taken together, our results highlight a novel role for DOCK7 in regulation of the replication stress response and highlight potential therapeutic targets to overcome chemoresistance in cancer.

Abstract Background: Crown-like structures in breast adipose tissue (CLS-B), indicative of proinflammatory conditions, are most frequently observed among obese (body mass index, BMI ≥30 kg/m2) women and may contribute to poor prognosis in this group. African-American (AA) women have disproportionately higher rates of obesity than White women, and at least one prior study suggests the prevalence of CLS-B may be higher among AA women. However, most previous studies have examined CLS-B within affected tissues, which may reflect inflammation in the tumor microenvironment, and few have examined the association between CLS-B and clinical outcomes by race. Methods: We examined the presence of CLS-B detected by CD68 immunohistochemistry in normal adjacent breast tissue from a quadrant uninvolved by tumor obtained via mastectomy among 174 African-American women and 168 White women with stage I—III breast cancer diagnosed at Emory University Hospitals (2007—2012). We also investigated associations between CLS-B and other demographic and lifestyle factors at diagnosis (e.g., BMI, smoking status, age at menarche, parity, lactation, menopausal status, hormone replacement therapy use, and family history of breast cancer). Patients were followed for an average of seven years after diagnosis for recurrence and survival. Multivariable Cox proportional hazards models were used to compute hazard ratios (HR) and 95% confidence intervals (CI) for associations between CLS-B presence and progression-free survival (PFS), controlling for BMI and other potential confounders. Results: Median age at diagnosis for both AA and White women was 54 years, with more than 60% postmenopausal among both groups. AA women were more likely than White women to be obese (52% vs. 24%) and have ER- tumors (30% vs. 12%). Presence of any CLS-B was similar between AA (32%) and White (29%) patients. In multivariable models, we did not find any association between CLS-B and race (HR=1.14, 95% CI: 0.72, 1.82) with the only statistically significant factors being BMI (≥30 vs. 18.5-<25 kg/m2: HR=4.36, 95% CI: 2.17, 8.76) and parity (1+ vs. 0 births: HR=0.43, 95% CI: 0.21, 0.91). Over follow-up, 46 breast cancer recurrences and 52 deaths (23 from breast cancer) occurred. Overall, the presence of CLS-B was not associated with PFS (multivariable HR: 0.97, 95% CI: 0.58, 1.62). When examined by race, there was a difference in the direction of the association between CLS-B and PFS among AA women (HR=1.25, 95% CI: 0.64, 2.46) compared to White women (HR=0.75, 95% CI: 0.33, 1.71), although this difference was not statistically significant (P=0.86). Conclusion: Our results show a strong, positive association between BMI and CLS-B in non-tumor tissue and an inverse association with parity. We did not observe a difference in CLS-B presence by race nor did we find CLS-B to be associated with worse progression-free survival, which is in contrast to previous studies that have examined the presence of CLS-B within specimens in close proximity to the tumor. Citation Format: Aswathy M Cheriyan, Mark E Sherman, Yuan Liu, Keerthi Gogineni, Jiaqi Liu, Jiabei He, Uma Krishnamurti, Ryan Ashiqueali, Jinjing He, Rami Yacoub, Jasmine Miller-Kleinhenz, Lauren E McCullough, Maret L Maliniak. Presence of crown-like structures in breast adipose tissue and clinical outcomes among African-American and White breast cancer patients [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr C074.

We clarify that DNA damage triggers autophagy by CHK2-FOXK axis, and misregulation of this pathway leads to chemoresistance.

Background Pancreatoblastoma (PBL) is a rare malignant pancreatic tumor seen predominantly in childhood, and its cytologic diagnosis remains challenging. Methods Twelve fine‐needle‐aspirations from 11 adults were analyzed. Results In total, 6 men and 5 women (median age, 45 years; age range, 32‐60 years) had tumors measuring a median 5.6 cm (range, 2.5‐12 cm) located in the pancreatic head (n = 7) or tail (n = 4), including 3 with familial adenomatous polyposis (FAP)/FAP‐related syndromes and 4 with metastasis at diagnosis. The median follow‐up was 39.8 months (range, 0.8‐348 months), and 5 patients died of disease. The original cytology diagnoses were: PBL (n = 2), neuroendocrine neoplasm (n = 2), poorly differentiated neuroendocrine carcinoma (n = 2), well differentiated neuroendocrine tumor (n = 1), poorly differentiated carcinoma (n = 2), “positive for malignancy” (n = 1), acinar cell carcinoma (n = 1), and epithelioid neoplasm with endocrine and acinar differentiation versus PBL (n = 1). Universal cytopathologic findings included hypercellularity; 3‐dimensional clusters; and single, monotonous, blast‐like cells that were from 1.5 to 2.0 times the size of red blood cells with high nuclear‐to‐cytoplasmic ratio, fine chromatin, small, distinct nucleoli, and a resemblance to well differentiated neuroendocrine tumor and poorly differentiated neuroendocrine carcinoma. Branching pseudopapillae (n = 7) and grooved nuclei (n = 3) raised the differential diagnosis of solid‐pseudopapillary neoplasm, but with more atypia. Uncommon features included pleomorphism (n = 4) and numerous mitoses (n = 1). Squamoid morules were seen on smears (n = 5) or cell blocks (n = 6) in 70% of patients and were characterized by epithelioid cells with elongated, streaming nuclei, fine chromatin, absent nucleoli, and positive nuclear β‐catenin (n = 6 of 8). The median Ki‐67 index was 21% (range, 2%‐70%), and neuroendocrine marker expression was common (100%), but acinar markers were variable (63%). Conclusions A combination of cytologic findings in PBL, including a predominant population of primitive blast‐like cells, subtle squamoid morules, frequent neuroendocrine and variable acinar phenotype, should facilitate accurate cytologic diagnosis and distinction from common mimics.

BackgroundHepatocellular carcinoma (HCC) rarely involves the biliary tree and may be inadvertently sampled on bile duct brushings (BDBs).MethodsThe pathology archives of 5 institutions were searched for BDBs with HCC involvement.ResultsA total of 17 BDBs from 14 patients were obtained. There was a male:female ratio of 6:1; the median age of the patients was 59.5 years (range, 22‐80 years). The median hepatic tumor size was 6.2 cm (range, 2.2‐13.0 cm). HCC risk factors included viral hepatitis (5 patients), cirrhosis (5 patients), hemochromatosis (1 patient), and alcoholic steatohepatitis (1 patient). Jaundice with elevated bilirubin, liver enzymes, and α‐fetoprotein was common. Endoscopic retrograde cholangiopancreatography demonstrated bile duct dilatation, polypoid intraductal masses (5 samples), clots/debris (2 samples), or strictures (4 samples). All BDBs had single and clustered large cells with naked atypical nuclei, granular cytoplasm, high nuclear/cytoplasmic ratios, and nuclei with prominent macronucleoli. Less common findings included clear/microvesicular cytoplasm (35%), papillae (29%), and anisonucleosis (35%). Classic HCC features (widened trabeculae [35%], endothelial wrapping [24%], multinucleation [24%], and cytoplasmic bile pigment [35%]) were uncommon. A total of 11 BDBs were diagnosed as malignant (10 with HCC and 1 with cholangiocarcinoma), 2 were diagnosed as atypical, and 1 BDB was diagnosed as negative; approximately two‐thirds were found to have polysomy on fluorescence in situ hybridization. Approximately 71% of patients died of disease at a median of 3.5 months.ConclusionsHCC may extend into the intrahepatic and/or extrahepatic biliary tree, causing masses and/or strictures that may be sampled on BDB. Although cytologically malignant, the classic features of HCC are uncommon, which can cause misdiagnosis. Cytopathologists should be mindful of this differential when evaluating BDBs, particularly when concomitant liver masses and/or HCC risk factors are present. Because of the associated high mortality and rapid rate of death, its presence should be conveyed clearly in pathology reports.

BACKGROUNDThe cytologic features of undifferentiated pancreatic carcinoma with osteoclastic giant cells (UOC) are rarely described.METHODSCytologic and clinicopathologic characteristics in 15 UOC fine‐needle aspiration (FNA) specimens were analyzed.RESULTSFNA specimens were obtained from 6 men and 8 women with a mean age of 65 years who had UOCs (head, n = 7; body, n = 3; and tail, n = 4) with a mean radiologic size 7.3 cm, and some had a cystic component (n = 9). Three cell types (osteoclastic giant cells, pleomorphic tumor giant cells, and spindled/histiocytoid cells) were observed in 12 of 15 specimens (80%); and pancreatic ductal adenocarcinoma (PDAC) was present in 11 specimens. FNA diagnoses were UOC (n = 6), PDAC (n = 5), poorly differentiated carcinoma (n = 2), “suspicious for neoplasm” (n = 1), and “negative” (n = 1). Five of 5 specimens with osteoclastic giant cells were positive for cluster of differentiation 68 (CD68) (a glycoprotein that binds to low‐density lipoprotein). Pleomorphic tumor giant cells and spindled/histiocytoid cells were positive for pancytokeratin (6 of 7 specimens), CAM5.2 (2 of 3 specimens), and epithelial membrane antigen (2 of 2 specimens). INI‐1 protein expression was retained in 3 of 3 specimens. The Ki‐67 labeling index was assessed in 3 specimens and was 12%, 18%, and 40%; 4 of 12 resected UOCs were pure, and 8 were mixed with PDAC. One resection specimen had intraductal papillary mucinous neoplasm, and 2 had mucinous cystic neoplasms. The median overall survival (OS) of patients who had UOCs identified on FNA was 8 months (6 died [OS, 8 months; range, 2‐22 months], and 8 remained alive [OS, 3 months; range, 1‐27 months]), which was similar to the survival of 74 patients who had PDACs identified on FNA (OS, 15 months; P = .279) but worse than that of the 27 patients with UOCs who did not undergo FNA (OS, 92 months; P = .0135).CONCLUSIONSThe 3 classical UOC cell types are identifiable on FNA, making cytologic diagnosis possible if considered in the differential. A PDAC component is often also observed. The survival advantage of UOC over pure PDAC appears to be negated by FNA and requires further investigation. Cancer Cytopathol 2017;125:563–75. © 2017 American Cancer Society.

Ultrasound vibro-acoustography is a novel medical imaging modality that combines the high resolution of high-frequency ultrasound with the speckle-free images obtained using low-frequency methods. This imaging modality relies on the non-linear interaction of two high frequency beams at slightly different frequencies. We describe the physics of ultrasound vibro-acoustography and outline a strategy for its modeling, simulation, and optimal design.