Biological Behavior Research Articles

Sarcomatoid and Rhabdoid Renal Cell Carcinoma: Clinical, Pathologic, and Molecular Genetic Features.

Renal cell carcinoma (RCC) with sarcomatoid and rhabdoid morphologies has an aggressive biological behavior and a typically poor prognosis. The current 2022 WHO classification of renal tumors does not include them as distinct histologic entities but rather as transformational changes that may arise in a background of various distinct histologic types of RCC. The sarcomatoid component shows malignant spindle cells that may grow as intersecting fascicles, which is reminiscent of pleomorphic undifferentiated sarcoma. The rhabdoid cells are epithelioid cells with eccentrically located vesicular nuclei with prominent nucleoli and large intracytoplasmic eosinophilic inclusions. Studies have shown that RCCs with sarcomatoid and rhabdoid differentiation have distinctive molecular features. Sarcomatoid RCC harbors shared genomic alterations in carcinomatous and rhabdoid components, but also enrichment of specific genomic alterations in the sarcomatoid element, suggesting molecular pathways for development of sarcomatoid growth from a common clonal ancestor. Rhabdoid differentiation also arises through clonal evolution although less is known of specific genomic alterations in rhabdoid cells. Historically, treatment has lacked efficacy, although recently immunotherapy with PD-1/PD-L1/CTLA-4 inhibitors has produced significant clinical responses. Reporting of sarcomatoid and rhabdoid features in renal cell carcinoma is required by the College of American Pathologists and the International Collaboration on Cancer Reporting. This manuscript reviews the clinical, pathologic, and molecular features of sarcomatoid RCC and rhabdoid RCC with emphasis on the morphologic features of these tumors, significance of diagnostic recognition, the molecular mechanisms of tumorigenesis and differentiation along sarcomatoid and rhabdoid lines, and advances in treatment, particularly immunotherapy.

[Advances in immunotherapy for pulmonary sarcomatoid carcinoma].

Pulmonary sarcomatoid carcinoma (PSC) is a rare, poorly differentiated non-small cell lung cancer (NSCLC) that contains sarcomatoid components or sarcomatoid differentiation, and accounts for less than 1% of all lung tumors. Compared to other types of NSCLC, PSC has more invasive biological behavior, is prone to metastasis, and has a higher recurrence rate after early surgery. Its greater resistance to traditional treatments leads to a poorer prognosis compared to other NSCLCs. Immunotherapy offers the possibility of long-term survival for PSC patients.

CLIC4 Function in the Epithelial-Mesenchymal Transition of Epithelial Odontogenic Lesions.

Odontogenic lesions constitute a heterogeneous group of lesions. CLIC4 protein regulates different cellular processes, including epithelial-mesenchymal transition and fibroblast-myofibroblast transdifferentiation. This study analyzed CLIC4, E-cadherin, Vimentin, and α-SMA immunoexpression in epithelial odontogenic lesions that exhibit different biological behavior. It analyzed the immunoexpression of CLIC4, E-cadherin, and Vimentin in the epithelial cells, as well as CLIC4 and α-SMA in the mesenchymal cells, of ameloblastoma (AM) (n = 16), odontogenic keratocyst (OKC) (n = 20), and adenomatoid odontogenic tumor (AOT) (n = 8). Immunoexpressions were categorized as score 0 (0% positive cells), 1 (< 25%), 2 (≥ 25% - < 50%), 3 (≥ 50% - < 75%), or 4 (≥ 75%). Cytoplasmic CLIC4 immunoexpression was higher in AM and AOT (p < 0.001) epithelial cells. Nuclear-cytoplasmic CLIC4 was higher in OKC's epithelial lining (p < 0.001). Membrane (p = 0.012) and membrane-cytoplasmic (p < 0.001) E-cadherin immunoexpression were higher in OKC, while cytoplasmic E-cadherin expression was higher in AM and AOT (p < 0.001). Vimentin immunoexpression was higher in AM and AOT (p < 0.001). Stromal CLIC4 was higher in AM and OKC (p = 0.008). Similarly, α-SMA immunoexpression was higher in AM and OKC (p = 0.037). Correlations in these proteins' immunoexpression were observed in AM and OKC (p < 0.05). CLIC4 seems to regulate the epithelial-mesenchymal transition, modifying E-cadherin and Vimentin expression. In mesenchymal cells, CLIC4 may play a role in fibroblast-myofibroblast transdifferentiation. CLIC4 may be associated with epithelial odontogenic lesions with aggressive biological behavior.

Notch-targeted Therapeutic in Colorectal Cancer by Notch1 Attenuation via Tumor Microenvironment-Responsive Cascade DNA Delivery.

The Notch signaling is a key molecular pathway that regulates cell fate and development. Aberrant Notch signaling can lead to carcinogenesis and progression of malignant tumors. However, current therapies targeting Notch pathway lack specificity and induce high toxicity. In this report, we design a tumor microenvironment-responsive and injectable hydrogel to load plasmid DNA complexes as a cascade gene delivery system to achieve precise Notch-targeted gene therapy of colorectal cancer (CRC). The hydrogels were prepared through cross-linking between phenylboric acid groups-containing poly(oligo(ethylene glycol)methacrylate) (POEGMA) and epigallocatechin gallate (EGCG), which were used to load the complexes between plasmid DNA encoding short hairpin RNAs of Notch1 (shNotch1) and fluorinated polyamidoamine (PAMAM-F) (PAMAM-F/shNotch1). In response to low pH and H2O2 in tumor microenvironment, the hydrogel can be dissociated and release the complexes for precise delivery of shNotch1 into tumor cells and inhibit Notch1 activity to suppress malignant biological behaviors of CRC. In the subcutaneous tumor model of CRC, PAMAM-F/shNotch1-loaded hydrogels can accurately attenuate Notch1 activity and significantly inhibit tumor growth without affecting Notch signal in adjacent normal tissues. Therefore, this therapeutic system can precisely inhibit Notch1 signal in CRC with high responsiveness and low toxicity, providing a promising Notch-targeted gene therapeutic for human malignancy. This article is protected by copyright. All rights reserved.

Synthesis and characterizations of MoS2 nanoflowers and spectroscopic study of their interaction with bovine serum albumin.

Molybdenum disulfide nanoflowers (MoS2 NFs) were prepared by hydrothermal method. The prepared MoS2 NFs was characterized by SEM, TEM, XRD, specific surface areas, Raman and XPS. The characterization results show that the flower-like spherical MoS2 is composed of many ultra-thin nanosheets with an average diameter of about 300-400 nm. MoS2 NFs also exhibits excellent absorption and high fluorescence intensity. In order to explore the biological behavior of MoS2 NFs, the interaction between MoS2 NFs and bovine serum albumin (BSA) was studied by UV-Vis absorption, fluorescence, synchronous fluorescence spectra, and cyclic voltammetry. The results of absorption and fluorescence show that MoS2 NFs and BSA interact strongly through the formation of complexes. The Stern-Volmer constant and the quenching constant was calculated about 3.79×107 L mol-1 and 3.79×1015 L mol-1 s-1, respectively. The synchronous fluorescence implied that MoS2 in the complex may mainly bind to tryptophan residues of BSA. The cyclic voltammograms indicated that the addition of BSA makes electron reduction of MoS2 NFs more difficult than the corresponding free state. These experimental results clarified the effective transportation and elimination of MoS2 NFs in the body by binding to BSA, and can provide useful guideline for estimating MoS2 NFs as a drug carrier.

Data-Driven Policy Learning Methods from Biological Behavior: A Systematic Review

Policy learning enables agents to learn how to map states to actions, thus enabling adaptive and flexible behavioral generation in complex environments. Policy learning methods are fundamental to reinforcement learning techniques. However, as problem complexity and the requirement for motion flexibility increase, traditional methods that rely on manual design have revealed their limitations. Conversely, data-driven policy learning focuses on extracting strategies from biological behavioral data and aims to replicate these behaviors in real-world environments. This approach enhances the adaptability of agents to dynamic substrates. Furthermore, this approach has been extensively applied in autonomous driving, robot control, and interpretation of biological behavior. In this review, we survey developments in data-driven policy-learning algorithms over the past decade. We categorized them into the following three types according to the purpose of the method: (1) imitation learning (IL), (2) inverse reinforcement learning (IRL), and (3) causal policy learning (CPL). We describe the classification principles, methodologies, progress, and applications of each category in detail. In addition, we discuss the distinct features and practical applications of these methods. Finally, we explore the challenges these methods face and prospective directions for future research.

Primary mucinous tumors of the renal pelvis: Clinical, histopathological, and molecular analysis of three cases

Primary mucinous tumors of the renal pelvis are extremely rare and pose challenges in terms of diagnosis and treatment. This study reviewed the clinical and pathological characteristics of mucinous tumors of the renal pelvis, including mucinous cystadenocarcinomas and mucinous cystadenomas. Immunohistochemical analysis was conducted in three cases, along with KRAS gene detection using the Amplification Refractory Mutation System (ARMS) method. The results revealed mucinous epithelium with acellular mucinous pools in all cases, and acellular mucinous pools were observed in the renal parenchyma and perirenal fat capsules. All tumors expressed CK20 and CDX2, and one case showed KRAS gene mutation. The study suggests that mucinous cystadenomas of the renal pelvis may exhibit borderline biological behaviors. This study is the first to report a KRAS gene mutation in a mucinous cystadenoma of the renal pelvis, offering valuable insights into the diagnosis and treatment of this rare condition.

PMS2 amplification contributes brain metastasis from lung cancer

BackgroundLung adenocarcinoma metastasizing to the brain results in a notable increase in patient mortality. The high incidence and its impact on survival presents a critical unmet need to develop an improved understanding of its mechanisms.MethodsTo identify genes that drive brain metastasis of tumor cells, we collected cerebrospinal fluid samples and paired plasma samples from 114 lung adenocarcinoma patients with brain metastasis and performed 168 panel-targeted gene sequencing. We examined the biological behavior of PMS2 (PMS1 Homolog 2)-amplified lung cancer cell lines through wound healing assays and migration assays. In vivo imaging techniques are used to detect fluorescent signals that colonize the mouse brain. RNA sequencing was used to compare differentially expressed genes between PMS2 amplification and wild-type lung cancer cell lines.ResultsWe discovered that PMS2 amplification was a plausible candidate driver of brain metastasis. Via in vivo and in vitro assays, we validated that PMS2 amplified PC-9 and LLC lung cancer cells had strong migration and invasion capabilities. The functional pathway of PMS2 amplification of lung cancer cells is mainly enriched in thiamine, butanoate, glutathione metabolism.ConclusionTumor cells elevated expression of PMS2 possess the capacity to augment the metastatic potential of lung cancer and establish colonies within the brain through metabolism pathways.

Dual roles of HK3 in regulating the network between tumor cells and tumor-associated macrophages in neuroblastoma

Neuroblastoma (NB) is the most common and deadliest extracranial solid tumor in children. Targeting tumor-associated macrophages (TAMs) is a strategy for attenuating tumor-promoting states. The crosstalk between cancer cells and TAMs plays a pivotal role in mediating tumor progression in NB. The overexpression of Hexokinase-3 (HK3), a pivotal enzyme in glucose metabolism, has been associated with poor prognosis in NB patients. Furthermore, it correlates with the infiltration of M2-like macrophages within NB tumors, indicating its significant involvement in tumor progression. Therefore, HK3 not only directly regulates the malignant biological behaviors of tumor cells, such as proliferation, migration, and invasion, but also recruits and polarizes M2-like macrophages through the PI3K/AKT-CXCL14 axis in neuroblastoma. The secretion of lactate and histone lactylation alterations within tumor cells accompanies this interaction. Additionally, elevated expression of HK3 in M2-TAMs was found at the same time. Modulating HK3 within M2-TAMs alters the biological behavior of tumor cells, as demonstrated by our in vitro studies. This study highlights the pivotal role of HK3 in the progression of NB malignancy and its intricate regulatory network with M2-TAMs. It establishes HK3 as a promising dual-functional biomarker and therapeutic target in combating neuroblastoma.

Comprehensive understanding of glioblastoma molecular phenotypes: classification, characteristics, and transition.

Among central nervous system-associated malignancies, glioblastoma (GBM) is the most common and has the highest mortality rate. The high heterogeneity of GBM cell types and the complex tumor microenvironment frequently lead to tumor recurrence and sudden relapse in patients treated with temozolomide. In precision medicine, research on GBM treatment is increasingly focusing on molecular subtyping to precisely characterize the cellular and molecular heterogeneity, as well as the refractory nature of GBM toward therapy. Deep understanding of the different molecular expression patterns of GBM subtypes is critical. Researchers have recently proposed tetra fractional or tripartite methods for detecting GBM molecular subtypes. The various molecular subtypes of GBM show significant differences in gene expression patterns and biological behaviors. These subtypes also exhibit high plasticity in their regulatory pathways, oncogene expression, tumor microenvironment alterations, and differential responses to standard therapy. Herein, we summarize the current molecular typing scheme of GBM and the major molecular/genetic characteristics of each subtype. Furthermore, we review the mesenchymal transition mechanisms of GBM under various regulators.

Uptake and Biotransformation of Guvermectin in Three Crops after In Vivo and In Vitro Exposure.

Guvermectin, as a novel nucleoside-like biopesticide, could increase the rice yield excellently, but the potential environmental behaviors remain unclear, which pose potential health risks. Therefore, the uptake and biotransformation of guvermectin in three types of crops (rice, lettuce, and carrot) were first evaluated with a hydroponic system. Guvermectin could be rapidly absorbed and reached equilibrium in roots (12-36 h) and shoots (24-60 h) in three plants, and guvermectin was also vulnerable to dissipation in roots (t1/2 1.02-3.65 h) and shoots (t1/2 9.30-17.91 h). In addition, 8 phase I and 2 phase II metabolites, transformed from guvermectin degradation in vivo and in vitro exposure, were identified, and one was confirmed as psicofuranine, which had antibacterial and antitumor properties; other metabolites were nucleoside-like chemicals. Molecular simulation and quantitative polymerase chain reaction further demonstrated that guvermectin was metabolized by the catabolism pathway of an endogenous nucleotide. Guvermectin had similar metabolites in three plants, but the biotransformation ability had a strong species dependence. In addition, all the metabolites exhibit neglectable toxicities (bioconcentration factor <2000 L/kg b.w., LC50,rat > 5000 mg/kg b.w.) by prediction. The study provided valuable evidence for the application of guvermectin and a better understanding of the biological behavior of nucleoside-like pesticides.

In Vitro Biocompatibility and Endothelial Permeability of Branched Polyglycidols Generated by Ring-Opening Polymerization of Glycidol with B(C6F5)3 under Dry and Wet Conditions.

Polyglycidol or polyglycerol (PG), a polyether widely used in biomedical applications, has not been extensively studied in its branched cyclic form (bcPG), despite extensive research on hyperbranched PG (HPG). This study explores the biomedical promise of bcPG, particularly its ability to cross the blood-brain barrier (BBB). We evaluate in vitro biocompatibility, endothelial permeability, and formation of branched linear PG (blPG) as topological impurities in the presence of water. Small angle X-ray scattering in solution revealed a fractal dimension of approximately two for bcPG and the mixture bc+blPG, suggesting random branching. Comparisons of cytotoxicity and endothelial permeability between bcPG, bc+blPG, and HPG in a BBB model using hCMEC/D3 cells showed different biocompatibility profiles and higher endothelial permeability for HPG. bcPG showed a tendency to accumulate around cell nuclei, in contrast to the behavior of HPG. This study contributes to the understanding of the influence of polymer topology on biological behavior.

Hepatocellular carcinoma in hepatitis C virus patients treated with direct acting antivirals (DAAs) and patients not exposed to DAAs: a large center comparative study

BackgroundHepatocellular carcinoma (HCC) is the first cause of cancer in Egypt. Recently, HCC developed post direct-acting antivirals (DAAs) differ in some characteristics from those developed without DAAs exposure regarding the biological features and behavior of HCC. We aimed to assess the epidemiological, clinical, laboratory, and radiological findings besides the biological behavior of HCC patients post DAAs in comparison to HCC not exposed to DAAs. An analytic cross-sectional research was performed at the National Liver Institute which is a tertiary multidisciplinary HCC center. Subjects included hepatitis C virus patients and were allocated into two groups: group I included 2036 HCC cases post-DAA treatment and group II included 6338 HCC cases who did not receive DAAs. Subjects were examined to evaluate clinical, laboratory, and radiological findings. Tumor staging was done using the BCLC staging system.ResultsGroup II showed a more advanced Child–Pugh score, FIB-4 index, and MELD score than Group I (P = 0.001). The multiplicity of hepatic focal lesions was elevated in group I than in group II (P = 0.033). AFP level was significantly elevated in group I than in group II (p = 0.012). Portal vein invasion was significantly elevated in group I than in group II patients (P = 0.001). Extrahepatic spread of HCC was significantly elevated in group I than in group II (P = 0.001). Infiltrative lesions were significantly elevated in group I than in group II (P = 0.002).ConclusionOur study detected that the behavior in HCC post DAAs treatment is more aggressive in respect of the number of lesions, PV invasion; local and distant metastasis, and serum AFP level than in patients unexposed to DAAs. Strict surveillance in cirrhotic patients treated with DAA should be followed according to the international guidelines for early diagnosis and treatment of HCC.

Defining oligometastatic state in uro-oncological cancers.

Oligometastatic tumors illustrate a distinct state between localized and systematic disease and might harbor unique biologic features. Moreover, these tumors represent a different clinical entity, with a potential of long-term disease control or even cure, therefore they receive growing attention in the field of urologic oncology. Currently, there is no consensus on the definition of oligometastatic prostate cancer, most experts limit it to a maximum of three to five lesions and involvement of no more than two organs, excluding visceral metastases. Quality data on oligometastatic bladder cancer is scarce, however, a consensus of experts defined it as a maximum of three metastatic lesions, either resectable or suitable for stereotactic therapy, without restrictions to the number of organs involved. As for kidney cancer, a maximum number of five metastases, without limitations to the location are defined as oligometastatic, with an important implication of timing of developing metastases since diagnosis of the primary tumor. Defining oligometastatic state among urological tumors reflecting their distinct biological and clinical behavior is crucial to establish a sound framework for future clinical trials, and to facilitate guideline and policy formulation for improved patient care. Advancements in molecular imaging are expected to transform the field of oligometastatic urologic tumors in the future.

Abstract PO5-03-12: Genomic differences of primary triple negative breast cancer in patients younger than 45 years vs. patients older than 45 years of age

Abstract Background: Triple negative breast cancer (TNBC) is often associated with an aggressive clinical course, especially in younger women. We previously demonstrated that there are differences in the genomic spectrum of metastatic TNBC in patients who are ≤45 years and those who are &amp;gt;45 years of age (Vidula et al, SABCS, 2020). Here we explore genomic differences of primary TNBC in patients ≤45 years and patients &amp;gt;45 years to understand variations in the overall number of non-silent mutations and proportion of patients with specific gene mutations. Methods: We obtained filtered mutation calls generated by the Multi-Center Mutation Calling in Multiple Cancers (MC3) working group (Ellrott et al, Cell Syst, 2018), from whole exome sequencing data of 9079 The Cancer Genome Atlas (TCGA) samples across 33 cancer types that had been used for the comprehensive characterization of cancer driver genes and mutations (Bailey et al, Cell, 2018). Receptor subtype and age at diagnosis of 1247 TCGA breast cancer samples were obtained from the UCSC Xena browser (Goldman et al, Nat Biotechnol, 2020). These datasets were combined to identify 119 patients with primary TNBC with harmonized high confidence mutation calls for analysis. We compared the overall number of non-silent mutations between patients ≤45 years vs. &amp;gt;45 years using the Wilcoxon rank sum test. We also compared the proportion of patients with non-silent mutations in genes mutated at &amp;gt;10% frequency between age groups using the Fisher Exact test. Results: Altogether, 25 patients ≤45 years and 94 patients &amp;gt;45 years were identified with primary TNBC. No significant difference in the number of non-silent mutations among patients ≤45 years vs. &amp;gt;45 years was seen (median [range], ≤45 years: 65 [5-228] vs. &amp;gt;45 years: 74 [2-742], Wilcoxon rank sum p=0.57). In total, 35 unique genes were mutated at &amp;gt;10% frequency in either patients ≤45 years (30 genes) or &amp;gt;45 years (7 genes); notably, TP53 mutations were commonly seen in both age groups (≤45 years: 76%; &amp;gt;45 years: 79%, p=0.79) and TTN mutations were also frequently mutated in both cohorts (≤45 years: 20%; &amp;gt;45 years: 27%, p=0.61). Among the 35 genes identified, 12 genes were mutated at significantly different frequencies among patients ≤45 years vs. those &amp;gt;45 years, as depicted in Table 1. Conclusions: Relatively high frequencies of TP53 and TTN mutations were seen in both patients ≤45 years and those &amp;gt;45 years with primary TNBC. However, many genes associated with varying cellular functions including motility, signaling receptors, and growth were more frequently mutated in patients ≤45 years. These results suggest that there are genomic differences of primary TNBC in patients ≤45 years vs. those &amp;gt;45 years. Further research is needed to validate these findings in a larger cohort of primary TNBC since genomic differences may affect tumor biology and clinical behavior. Table 1. Significant Gene Mutation Differences in Primary TNBC Based on Age. Citation Format: Neelima Vidula, Leif Ellisen, Aditya Bardia, Christina Yau. Genomic differences of primary triple negative breast cancer in patients younger than 45 years vs. patients older than 45 years of age [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-03-12.

Abstract PO5-18-10: Omission of SLNB in triple-negative and HER2-positive breast cancer patients with radiologic and pathologic complete response in the breast after NAST: a single-arm, prospective surgical trial (EUBREAST-01 trial, GBG 104)

Abstract Background: Currently, axillary surgery for breast cancer is considered a staging procedure that does not seem to influence breast cancer mortality since the risk of developing metastasis depends mainly on the biological behavior of the primary (seed-and-soil model). Based on this, postsurgical therapy should be considered based on biological tumor characteristics. Retrospective data of cancer registry trials showed a strong correlation between breast pathologic complete response (pCR) and nodal pCR depending on intrinsic subtypes. Improvements in systemic treatments for breast cancer have increased the rates of pCR in patients receiving neoadjuvant systemic therapy (NAST), offering the opportunity to decrease, and perhaps eliminate, surgery in patients who have a pCR. Trial design: The EUBREAST network designed a clinical trial (NCT04101851) in which only patients with the highest likelihood of having a pCR after NAST (triple-negative or HER2-positive breast cancer) will be included, and type of surgery will be defined according to the response to NAST rather than on the classical T and N status at presentation. In the ongoing trial, axillary surgery will be eliminated (no axillary sentinel lymph node biopsy [SLNB]) for initially clinical node-negative (cN0) patients with radiologic complete remission (rCR) and a breast pCR (ypT0/ypTis) as determined in the lumpectomy specimen. The trial design is a multicenter single-arm study with a limited number of patients (N=440 as the screening population with an expected 80% pCR-rate) which might give practice-changing results in a short period, sparing the time and the costs of a randomized comparison. Patients will be recruited in European countries (Austria, Germany, Italy, and Spain) over 48 months. Inclusion criteria: -Written informed consent -Histologically confirmed unilateral primary invasive carcinoma of the breast (core biopsy). Multifocal or multicentric tumors are allowed if breast-conserving surgery (BCS) is planned. -Age at diagnosis at least 18 years -imaging techniques with estimated tumor stage between cT1-T3 before NAST -triple-negative (TNBC) or HER2-positive invasive breast cancer -TNBC is defined by: ER-negative (&amp;lt; 10% positive cells in IHC) and PgR-negative (&amp;lt; 10% positive cells in IHC), HER2-negative -clinically and sonographically tumor-free axilla before core biopsy (cN0/iN0) -in cases with cN0 and iN+, a negative core biopsy or fine-needle aspiration biopsy of the sonographically suspected lymph node is required -no evidence for distant metastasis (M0) -standard NAST with rCR -planned BCS with postoperative external whole-breast irradiation (conventional fractionation or hypofractionation) Primary objective: 3-year rate of axillary recurrence-free survival (ARFS) after BCS Statistics: The calculated total case number for per-protocol analysis is N=350, and the expected total number of screened patients is N=440. The assumption for acceptable 3-year ARFS ≥98.5% in the experimental arm is based on previous study findings. Timelines: -First patient in: January 2021 -Last patient in: December 2024 -Primary outcome analysis: Q1/2027 Current accrual: In June 2023, 255 patients were recruited; the majority of them in Germany. Contact: Prof. Dr. Toralf Reimer (eubreast-01@kliniksued-rostock.de), study chair Dr. Oreste D. Gentilini (gentilini.oreste@hsr.it), study co-chair Funding by Else Kroener-Fresenius Foundation, German Society of Senology, University of Rostock (Germany), and San Raffaele Hospital (Milan, Italy). Citation Format: Toralf Reimer, Bernd Gerber, Thorsten Kuehn, Nikola Bangemann, Anke Kleine-Tebbe, Andrea Stefek, Ulrike Doerste, Carolin Hammerle, Oliver Hoffmann, Alexander Hein, Isabel Rubio, Florentia Peintinger, Keyur Mehta, Sibylle Loibl, Edoardo Botteri, Oreste Gentilini. Omission of SLNB in triple-negative and HER2-positive breast cancer patients with radiologic and pathologic complete response in the breast after NAST: a single-arm, prospective surgical trial (EUBREAST-01 trial, GBG 104) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-18-10.

Abstract PO4-28-07: SLC26A9 promotes triple-negative breast cancer progression by regulating lipid metabolism

Abstract Background: The disturbance of lipid metabolism in the microenvironment plays an important role in the occurrence and development of triple-negative breast cancer(TNBC). SLC26A9, a member of the SLC26A family of anion transporters, is involved in breast oncogenesis. However, the effect of SLC26A9 in triple-negative breast cancer on lipid metabolism in the tumor microenvironment remains unclear. Methods: Bioinformatics, tissue microarrays and TNBC cell lines were used to detect the expression of SLC26A9 and its clinical significance. By altering the expression of SLC26A9 gene in TNBC cells, the effects of SLC26A9 on the regulation of lipid metabolism, cell biological behavior and its related molecular mechanisms in the TNBC microenvironment were explored using adoptive staining techniques, flow cytometric analysis and animal models. Results: We found by tissue microarray (TNBC=105 cases, Nor=67 cases) that the expression of SLC26A9 was significantly up-regulated in BC compared to paracancerous tissues, where SLC26A9 expression was higher in TNBC, and the same results were obtained in BC cell lines. Secondly, we found that SCL26A9 was positively correlated with lipid metabolism status in TNBC microenvironment and possessed a close association with P53 mutation by analyzing GEO and TCGA databases. Therefore, we used two cell lines (MDA-MB-231, MDA-MB-468) in which SCL26A9 was highly expressed in TNBC cell lines. It was demonstrated by oil red O staining and lipid fluorescence staining that knockdown/silencing of SLC26A9 diminished the ability of MDA-MB-231 and MDA-MB-468 cells to uptake and utilize lipids, especially for metabolites such as neutral lipids: triglycerides, lipid droplets, and steroidal substances. Then we demonstrated by using fatty acid flow cytometric analysis that knockdown/silencing of SLC26A9 significantly reduced the utilization and production of fatty acids in MDA-MB-231 and MDA-MB-468 cells, which are the key metabolic indicators of cancer cells as well as important energy-providing substances for cancer progression. Therefore, we further verified functionally that cell proliferation, migration, invasion and anti-apoptosis were significantly inhibited in in vitro after knockdown/silencing of SLC26A9, and in vivo tumorigenesis was significantly inhibited in BALB/c nude mice in in vivo. In addition, the expression of markers of lipid metabolic activity (FASN, ACLY) was reduced after knockdown/silencing of SLC26A9 in MDA-MB-231 cells by Western Blot, and the reduced expression of FASN and ACLY mainly inhibited the ab initio synthesis, uptake and utilization of fatty acids in TNBC cells, which in turn regulated the proliferation and invasion of TNBC. Mechanistically, SLC26A9 silencing/knockdown inhibited the synthesis, uptake, and utilization of multiple metabolites of lipids in TNBC, which combined with the TCGA database results revealed the activation of the key signaling pathway, the JAK-STAT3 signaling pathway, to promote the progression of TNBC. Conclusion(s): SLC26A9 is involved in the disturbance of lipid metabolism in the TNBC microenvironment and regulates the progression of TNBC. The search for new SLC26A9 inhibitors is expected to provide a new direction for the treatment of TNBC, but the exact molecular mechanisms need to be further explored. SLC26A9 upregulation in TNBC leads to a poor prognosis by referencing lipid metabolism in the TNBC microenvironment Wench. SLC26A9 is involved in lipid metabolism disorders and cell biological functions in the TNBC microenvironment in vivo. SLC26A9 is involved in disordered lipid metabolism in the TNBC microenvironment. Citation Format: Yingming Zhou, Hu Wang, Zhengxing Zhou, Xuemei Liu, Biguang Tuo, Taolang Li. SLC26A9 promotes triple-negative breast cancer progression by regulating lipid metabolism [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-28-07.

Abstract PO3-24-07: The role of Hepatitis A Virus Cellular Receptor 1 (HAVCR1) in breast cancer and the impact on penetration of blood brain barrier

Abstract Background: Hepatitis A Virus Cellular Receptor 1 (HAVCR1) is associated with the biological behaviour of several cancers, and has been shown to regulate junctional complexes. However, its role in breast cancer remains unexplored. This study aimed to investigate the effects of HAVCR1 on human breast cancer. Methods: We explored the UALCAN web portal, which is linked to the TCGA database, to determine the expression of HAVCR1 in breast cancer and the Kaplan-Meier plotter to evaluate the correlation with the survival of the patients. HAVCR1 siRNA was used to knock down the HAVCR1 expression in MCF-7 and MDA-MB-231 cell lines. In vitro cell growth, wounding healing, and electric cell impedance sensing (ECIS for assessing cellular proliferation, migration and adhesion) assays were used. Transepithelial resistance (TEER) and paracellular permeability (PCP) were assessed to determine changes in the barrier function of human breast cancer cells. The expression of HAVCR1 and prospective interactive binding molecules of HAVCR1 protein was assessed using quantitative polymerase chain reaction (qPCR). Cellular response to docetaxel was evaluated and shown (IC50). The invasiveness of breast cancer cells through the human cerebral microvessel endothelial cells (hCMEC/D3) cell layers was measured using an in vitro transwell cell invasion assay. Results: HAVCR1 gene expression levels were significantly lower (P&amp;lt; 0.001) in breast cancer tissue compared with normal tissues. Patients with high expression of HAVCR1 had a significantly better relapse-free survival than low expression (P&amp;lt; 0.001). There was no significant difference in overall survival (OS) between the HAVCR1 high and the low expression groups (P=0.22). However, in subgroup analysis, high HAVCR1 expression was associated with better OS in luminal A (P=0.04). Knockdown (KD) HAVCR1 in breast cancer cells influence cell function by enhanced adhesion, proliferation, and migration compared to wild type (WT) cell lines. It was noted that loss of HAVCR1 rendered both MCF-7 and MDA-MB-231 cells resistant to docetaxel (IC50 for WT and HAVCR1 KD respectively being 0.86nM vs 1.75nM for MCF-7 and 1.35nM vs 15.48nM for MDA-MB-231). HAVCR1 KD increase adhesion to hCMEC/D3 cells (53.14±8.23 vs ±99.37±8.97 for MCF-7, P&amp;lt; 0.001; 109.5±97.56 vs 147.1±96.63 for MDA-MB-231, P=0.228, WT and HAVCR1 KD). In the cerebral endothelial cell invasion assay, we found that HAVCR1 KD resulted in a significantly increased invasion of the breast cancer cells through the endothelium (19.27±8.74 vs 33.58±16.81 for MDA-MB-231, P=0.0114, WT and HAVCR1 KD). For the barrier function, the knockdown led to a decrease in TEER and an increase in PCP when compared with WT cells in both cell lines. HAVCR1 KD cells showed decreased barrier function, together with reduced expression of Claudin-1/8/10, occludin, MarvelD3, Tricellulin and ZO1. Conclusions: HAVCR1 is a potential biomarker for breast cancer prognosis. HAVCR1 influences the integrity of barrier function by influence the gene expression of tight junction in breast cancer, and influence the penetration to blood brain barrier. Together, it suggests that HAVCR1 may be a potential therapeutic target in breast cancer. Citation Format: Xiaoshan Cao, Binbin Cong, Wen Jiang, Tracey Martin. The role of Hepatitis A Virus Cellular Receptor 1 (HAVCR1) in breast cancer and the impact on penetration of blood brain barrier [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-24-07.

Abstract PO1-23-08: Exosome-based delivery of microRNAs confers adriamycin-resistance to sensitive cells through modulating the immune and metabolism-related gene PTEN in HER2-negative breast cancer

Abstract Background: Anthracycline-based chemotherapy is widely used to treat breast cancer. However, acquired drug resistance remains a challenge to successful treatment. Recently, increasing evidence has shown that changes in the tumour immune microenvironment (TIME), in addition to increasing drug resistance of tumour cells, consistently contribute to the development of chemoresistance. Methods: TIME scores and tumor-infiltrating immune cells (TICs) scores were used to investigate the prognosis, clinicopathological characteristics and gene transcriptome profiling of HER2-negative breast cancer patients who received anthracycline-based chemotherapy. Exosomes isolated from MCF/7-ADR (ADR-exos) and MCF/7-S (S-exos) cell lines were characterized. We identified dysregulated miRNAs using miRNA microarray analysis on MCF/7-ADR cells and their exosomes compared to MCF/7-S cells and their exosomes. Protein profiling was performed to identify differentially expressed proteins in up- and down-regulated miR-222 cells. The ability of ADR-exos to transfer drug-resistance mediated by miR-222 was assessed by immunofluorescence assay, flow cytometry and qRT-PCR. We optimized the conditions to load miR-222 mimic (or inhibitor) into exosomes produced by HBL-100 cells (H-exos). The influence of miR-222 inhibitor-containing exosomes (inhibitor-exos) on the downstream pathway of miR-222 and the potential therapeutic effects both in vitro and in vivo were evaluated. We also evaluated the relationship between miR-222/PTEN and drug resistance in circulating exosomes from mice after adriamycin-based chemotherapy. Results: Firstly, we discovered the complicated and heterogenous TICs subtypes and their unique biological behaviors in HER2-negative breast cancer. Then, we identified 85 differentially expressed immunologic signature gene sets and 7202 corresponding immune-related genes in three subtypes quantified by gene set variation analysis (GSVA). We identified 12 up-regulated and 13 down-regulated genes using miRNA microarray analysis in adriamycin-resistant cells and their exosomes. The TMT mass spectrometry found 45 differentially expressed proteins affected by the miR-222 level. Moreover, we successfully established miRNA mimic/inhibitor-containing exosomes to explore the solo function of exosomal miR-222 in adriamycin-resistance both in vitro and in vivo. More importantly, for the first time, we detected the levels of miR-222 and its target gene PTEN in circulating exosomes from mice after adriamycin-based chemotherapy and explored the potential clinical implications of miR-222/PTEN-containing exosomes in chemotherapy and immune suppression of breast cancer patients. Conclusions: HER2-negative breast cancer patients own unique TIME subtypes, leading to different outcomes of chemotherapy. We exhibit the potential applications of miR-222-mimic/inhibitor-containing exosomes for reversing chemo-resistance. Adriamycin-resistant cells can transmit drug-resistance to sensitive cells via delivering miR-222 by modulating the immune- and metabolism-related target gene PTEN both in vitro and in vivo without interference from other relevant drug-resistance factors in exosomes. Therefore, miR-222-containing exosomes as well as their target gene PTEN may be a promising biomarker for predicting the efficacy of chemo-resistance and tumor immunity regulation in breast cancer patients receiving anthracycline-based chemotherapy. Keywords: exosomes, breast cancer, tumor immune microenvironment, chemo-resistance, microRNAs Citation Format: Sujin Yang, Tian-cheng Cheng, Jia-hao Wu, Wei-xian Chen. Exosome-based delivery of microRNAs confers adriamycin-resistance to sensitive cells through modulating the immune and metabolism-related gene PTEN in HER2-negative breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-23-08.

Abstract PO5-06-11: RPL27A promotes the growth and metastasis of triple negative breast cancer by regulating Ribosome biogenesis

Abstract Background: Ribosome is a complex structure in cells for protein synthesis. It has been considered always have a constant composition. Recent studies have revealed that the Ribosome composition of tumor cells is heterogeneous. The Ribosome protein composition, post-translational modification, rRNA modification, and rRNA variants can lead to the existence of specialized "onco-ribosomes" in tumor cells, which regulates the rate of translation and protein synthesis, and can affect the occurrence and development of tumors significantly. The abnormal expression of multiple Ribosome proteins in triple-negative breast cancer may be the target of its diagnosis and treatment, also, an independent factor in prognosis evaluation. Methods: To learn the expression levels of Ribosome biogenesis related genes in normal breast cells and abnormal breast cells with different pathological subtypes of breast cancer, the following studies have been done: 1. Bioinformatics analysis on TCGA database and single-cell sequencing data; 2. IHC detection on TNBC tissue and adjacent tissues; 3. Determine the expression level of RPL27A in TNBC cells, and analyze the correlation between the expression of RPL27A and clinical information of patients. To explore the effect of RPL27A on Ribosome biogenesis, protein synthesis and other signaling pathways through Proteomics and molecular biology experiments have been designed and tested. The effects of RPL27A on malignant biological behaviors such as proliferation, migration, infiltration, and clonal formation of TNBC cells were studied through cell biology experiments and mouse experiments. Results: The analysis of TCGA database and single-cell sequencing data showed that the RPL27A was significantly increased in TNBC group. Immunohistochemical experiments showed that RPL27A was highly expressed in TNBC tissue and was impressively positively correlated with tumor size, lymph node metastasis, and bone metastasis. There was significantly negatively correlated with overall survival (OS) and disease free survival (DFS). It can be an independent factor for evaluating the prognosis of TNBC. By knocking out RPL27A in TNBC cell line, label free proteomics analysis showed that Ribosome biogenesis, protein synthesis, cell cycle regulation and other signaling pathways were obviously down regulated. Cell biology experiments have implied that the high expression of RPL27A in TNBC promotes cell proliferation, enhances cell migration, infiltration, and cloning ability, leads to more malignant biological behavior of tumor cells. Further research demonstrates that the high expression of RPL27A in TNBC significantly activated the EIF3C signal, cause changes in the composition of Ribosome in TNBC cells, promoted the formation of "onco-ribosomes", and distinctly increased the rate of protein synthesis. The study of PDX mice and Organoid showed that the knock out of RPL27A significantly reduced the growth rate and transfer ability of TNBC. Conclusion: The obvious over expressing of RPL27A in TNBC, which can significantly promote the growth and metastasis of tumor cells by influencing the Ribosome biogenesis process. Citation Format: Weipeng Zhao, Jingyi Zhang, Ye Zhu, Xin Yang, Xichuan Li. RPL27A promotes the growth and metastasis of triple negative breast cancer by regulating Ribosome biogenesis [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-06-11.