Characterization of the AGR2-NPM3 axis uncovers the AGR2 involvement in PD-L1 regulation in colorectal cancer.

Despite extensive research, the molecular role of AGR2 in the progression and metastasis of colorectal cancer (CRC) has not been fully characterized. We used quantitative mass spectrometry (SWATH MS) to identify differentially expressed proteins in paired CRC cell models of the SW480 and SW620 cell lines in response to AGR2 protein level manipulation. Relying on the results from SWATH MS and subsequent immunochemical validation, we selected NMP3 as the top candidate protein associated with AGR2 in CRC tumour cells in our screen. RT‒qPCR and immunochemical analysis confirmed the involvement of AGR2-mediated regulation of NPM3 at the transcriptional and posttranscriptional levels. Since PD-L1 is a constituent of the NPM3 regulatory axis, we aimed to correlate the changes in PD-L1 to the differential expression of AGR2 in our cell models. We found that AGR2 positively regulates PD-L1 levels in both SW480 and SW620 cell lines; additionally, several different CRC patient transcriptome cohorts confirmed the association of AGR2 with PD-L1. Our work reveals a new AGR2-NPM3 regulatory axis and the involvement of AGR2 in the regulation of PD-L1, which paves the way for the association of AGR2 with immune evasion in CRC cells.

AGR2 facilitates teratoma progression by regulating glycolysis via the AnXA2/EGFR axis.

Anterior gradient-2 (AGR2) is highly expressed in several tumors and plays an important role in tumor development. However, the biological function of AGR2 in teratomas has not yet been thoroughly studied. In this study, AGR2 was found to be upregulated in teratoma tissues and in human testicular teratoma cell lines by Western blotting and qRT-PCR assays. A DNA Methylation-Specific PCR assay demonstrated that AGR2 upregulation resulted from hypomethylated AGR2 in teratoma cells. NCC-IT and NT2-D1 cells were transfected with pcDNA-AGR2 or sh-AGR2 to obtain AGR2-overexpressed or -silenced cells, and cell proliferation, invasion and glycolysis were determined using CCK-8, 5-ethynyl-2'-deoxyuridine (EdU), Transwell assays, and commercial kits. The results revealed that overexpression of AGR2 promoted teratoma cell proliferation and invasion and elevated glycolysis levels evidencing by the increase in lactate secretion, glucose consumption, ATP levels and the expression of glycolysis-related proteins, while knockdown of AGR2 showed the opposite results. The interactions between AGR2 and annexin A2 (AnXA2), as well as between AnXA2 and epidermal growth factor receptor (EGFR) were verified by co-immunoprecipitation assay. Mechanistic studies revealed that AGR2 interacts with AnXA2 and increases the level of AnXA2 to recruit more AnXA2 to EGFR, there by promoting EGFR expression. A series of rescue experiments showed that knockdown of AnXA2 or EGFR weakened the promotional effects of AGR2 overexpression on the proliferation, invasion, and glycolysis of teratoma cells. Finally, tumorigenicity assays were performed using NT2-D1 cells stably transfected with either LV-NC-shRNA or LV-shAGR2. The results showed that AGR2 knockdown significantly inhibited teratoma tumor growth in vivo. In conclusion, our data suggested that AGR2 facilitates glycolysis in teratomas through promoting EGFR expression by interacting with AnXA2, thereby promoting teratoma cells proliferation and invasion.

POTENTIAL DIAGNOSTIC BIOMARKERS FOR HUMAN MESENCHYMAL TUMORS, ESPECIALLY LMP2/Β1I AND CYCLIN E1/MIB1 DIFFERENTIAL EXPRESSION: PRUM-IBIO STUDY.

Most mesenchymal tumors found in the uterine corpus are benign tumors; however, uterine leiomyosarcoma is a malignant tumor with unknown risk factors that repeatedly recurs and metastasizes. In some cases, the histopathologic findings of uterine leiomyoma and uterine leiomyosarcoma are similar and surgical pathological diagnosis using excised tissue samples is difficult. It is necessary to analyze the risk factors for human uterine leiomyosarcoma and establish diagnostic biomarkers and treatments. Female mice deficient in the proteasome subunit low molecular mass peptide 2 (LMP2)/ß1i develop uterine leiomyosarcoma spontaneously. MATERIAL AND METHODS: Out of 334 patients with suspected uterine mesenchymal tumors, patients diagnosed with smooth muscle tumors of the uterus were selected from the pathological file. To investigate the expression status of biomarker candidate factors, immunohistochemical staining was performed with antibodies of biomarker candidate factors on thin-cut slides of human uterine leiomyosarcoma, uterine leiomyoma, and other uterine mesenchymal tumors. RESULTS AND DISCUSSION: In human uterine leiomyosarcoma, there was a loss of LMP2/ß1i expression and enhanced cyclin E1 and Ki-67/MIB1 expression. In human uterine leiomyomas and normal uterine smooth muscle layers, enhanced LMP2/ß1i expression and the disappearance of the expression of E1 and Ki-67/MIB1 were noted. The pattern of expression of each factor in other uterine mesenchymal tumors was different from that of uterine leiomyosarcoma. CONCLUSIONS: LMP2/ß1i, cyclin E1, and Ki-67/MIB1 may be candidate factors for biomarkers of human uterine leiomyosarcoma. Further large-cohort clinical trials should be conducted to establish treatments and diagnostics for uterine mesenchymal tumors.

Structure-Based Drug Design of 2-Amino-[1,1'-biphenyl]-3-carboxamide Derivatives as Selective PKMYT1 Inhibitors for the Treatment of CCNE1-Amplified Breast Cancer.

CCNE1 amplification occurs in breast cancer and currently lacks effective therapies. PKMYT1 as a synthetic lethal target for CCNE1 amplification holds promise for the treatment of CCNE1-amplified breast cancer. Herein, we discover a series of 2-amino-[1,1'-biphenyl]-3-carboxamide derivatives as potent and selective PKMYT1 inhibitors using structure-based drug design. The representative compound 8ma exhibited excellent potency against PKMYT1, while sparing WEE1. It also suppressed proliferation of the CCNE1-amplified HCC1569 breast cancer cell line and showed synergistic cytotoxicity in combination with gemcitabine. PKMYT1 X-ray cocrystallography confirmed that introduction of key binding interactions between the inhibitors and residues Asp251 and Tyr121 of PKMYT1 greatly enhanced the potency and selectivity of the compounds.

The role of palbociclib on the alterations in CDKN2, CCNE1, E2F3, MDM2 expressions as target genes of miR-141.

INTRODUCTION: According to WHO, Breast cancer is widely considered to be the first or second cause of cancer-related death almost universally. Cell cycle disruption, either in the form of uncontrolled expression of cyclins or because of the suspension in negative regulatory proteins (CDK inhibitors), was found to cause breast cancer. Palbociclib as specific CDK4/6 inhibitor is used for the treatment of ER+ metastatic cancers. In this study, we are looking to investigate the effect of palbociclib on breast cancer cells and evaluate the changes in the expression of some genes involved in the cell cycle as target genes of miR-141 after treatment with this drug. We used MCF7 as functional estrogen and non-invasive and MDA-MB-231 cell lines as triple-negative type of breast cancer and a model for more aggressive. METHOD & MATERIALS: MCF7 and MDA-MB-231 cell lines were cultured in DMEM medium. After counting cells and measuring viability, Palbociclib was administered at varying doses using the IC50 obtained from MTT, with the treatment given at two time points of 24 and 72 hours. RNA was extracted from untreated and treated cells and RNAs were converted to cDNA in the end. Gene expression changes were investigated by real-time PCR. Data management and analysis were conducted using GraphPad Prism 5.01 software. RESULT AND CONCLUSION: Among investigated genes, E2F3 gene was not significantly affected by Palbociclib in any of cell lines and time points. Besides, the expression of CCNE1 gene was significantly suppressed. It seems this drug was unable to reduce the expression of MDM2 gene significantly in triple negative (MDA-MB-231) cancer cells; however, a decrease was observed in luminal A (MCF-7) cells. CDKN2A and miR-141 genes expression increased significantly after treatment which can be aligned with palbociclib in proliferation inhibition.

PARK2 suppresses the proliferation of high-grade serous ovarian carcinoma via inducing the proteasomal degradation of ZNF703.

High-grade serous ovarian cancer (HGSC) is an aggressive disease with poor prognosis. The oncoprotein ZNF703 is implicated in driving HGSC pathogenesis, but factors regulating its abundance remain unclear. In this study, we aim to investigate the potential connection between ZNF703 dysregulation and ubiquitin-mediated protein degradation in HGSC. Bioinformatics prediction was performed using BioGRID database. HGSC representative cell lines were utilized for in vitro and in vivo studies. Results showed that ZNF703 protein was stabilized upon proteasome inhibition, suggesting a regulation via ubiquitination. The ubiquitin E3 ligase PARK2 was found to interact with ZNF703 in a dose-dependent manner, promoting its polyubiquitination and subsequent proteasomal degradation. Re-expression of PARK2 in HGSC cells led to reduced ZNF703 levels together with decreased Cyclin D1/E1 abundance and G1 cell cycle arrest. ZNF703 overexpression alone increased S phase cells, Cyclin D1/E1 levels, and xenograft tumor growth, while co-expression with PARK2 mitigated these oncogenic effects. Collectively, our findings identify ZNF703 as a bona fide substrate of PARK2, reveal a tumor suppressive function for PARK2 in attenuating ZNF703-mediated G1/S transition and HGSC growth through instigating its degradation. This study elucidates a pivotal PARK2-ZNF703 axis with therapeutic implications for targeted intervention in HGSC.

AGR2: The Covert Driver and New Dawn of Hepatobiliary and Pancreatic Cancer Treatment.

The anterior gradient protein 2 (AGR2) plays a crucial role in facilitating the formation of protein disulfide bonds within the endoplasmic reticulum (ER). Research suggests that AGR2 can function as an oncogene, with its heightened expression linked to the advancement of hepatobiliary and pancreatic cancers through invasion and metastasis. Notably, AGR2 not only serves as a pro-oncogenic agent but also as a downstream targeting protein, indirectly fostering cancer progression. This comprehensive review delves into the established functions and expression patterns of AGR2, emphasizing its pivotal role in cancer progression, particularly in hepatobiliary and pancreatic malignancies. Furthermore, AGR2 emerges as a potential cancer prognostic marker and a promising target for immunotherapy, offering novel avenues for the treatment of hepatobiliary and pancreatic cancers and enhancing patient outcomes.

Functional ex vivo DNA fibre assay to measure replication dynamics in breast cancer tissue.

Replication stress (RS) is a key trait of cancer cells, and a potential actionable target in cancer treatment. Accurate methods to measure RS in tumour samples are currently lacking. DNA fibre analysis has been used as a common technique to measure RS in cell lines. Here, we investigated DNA fibre analysis on fresh breast cancer specimens and correlated DNA replication kinetics to known RS markers and genomic alterations. Fresh, treatment-naïve primary breast cancer samples (n = 74) were subjected to ex vivo DNA fibre analysis to measure DNA replication kinetics. Tumour cell proliferation was confirmed by EdU incorporation and cytokeratin AE1/AE3 (CK) staining. The RS markers phospho-S33-RPA and γH2AX and the RS-inducing proto-oncogenes Cyclin E1 and c-Myc were analysed by immunohistochemistry. Copy number variations (CNVs) were assessed from genome-wide single nucleotide polymorphism (SNP) arrays. We found that the majority of proliferating (EdU-positive) cells in each sample were CK-positive and therefore considered to be tumour cells. DNA fibre lengths varied largely in most tumour samples. The median DNA fibre length showed a significant inverse correlation with pRPA expression (r = -0.29, p = 0.033) but was not correlated with Cyclin E1 or c-Myc expression and global CNVs in this study. Nuclear Cyclin E1 expression showed a positive correlation with pRPA levels (r = 0.481, p < 0.0001), while cytoplasmic Cyclin E1 expression exhibited an inverse association with pRPA expression (r = -0.353, p = 0.002) and a positive association with global CNVs (r = 0.318, p = 0.016). In conclusion, DNA fibre analysis performed with fresh primary breast cancer samples is feasible. Fibre lengths were associated with pRPA expression. Cyclin E1 expression was associated with pRPA and the percentage of CNVs. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Regulation of RHOV signaling by interaction with SH3 domain-containing adaptor proteins and phosphorylation by PKA.

RHOV and RHOU are considered atypical Rho-family small GTPases because of the existence of N- and C-terminal extension regions, abnormal GDP/GTP cycling, and post-translational modification. Particularly, RHOV and RHOU both have a proline-rich (PR) motif in the N-terminal region. It has been reported that the PR motif of RHOU interacts with GRB2, a SH3 domain-containing adaptor protein, and regulates its activity through EGF receptor signaling. However, it is unknown whether RHOV, like RHOU, interacts with SH3 domain-containing adaptor proteins. In this study, we investigated the interactions between RHOV and SH3 domain-containing adaptor proteins, including GRB2 and NCK2. The RHOV-induced serum response factor (SRF)-dependent gene transcriptional activity was attenuated in cells co-expressing either GRB2 or NCK2 compared to cells expressing RHOV alone. From the results of experiments using various gene mutants of RHOV and GRB2, it appears that the PR motif of the N-terminal region of RHOV is the crucial binding site for the SH3 domain-containing proteins. Furthermore, we found that Ser25 in the N-terminal region of RHOV is phosphorylated by PKA and that its phosphorylation is suppressed by interaction with NCK2 but not GRB2. We have found a novel regulatory mechanism for the phosphorylation of RHOV and its interaction with SH3 domain-containing adaptor proteins.

LAPTM4B counteracts ferroptosis via suppressing the ubiquitin-proteasome degradation of SLC7A11 in non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related deaths worldwide, necessitating the identification of novel therapeutic targets. Lysosome Associated Protein Transmembrane 4B (LAPTM4B) is involved in biological processes critical to cancer progression, such as regulation of solute carrier transporter proteins and metabolic pathways, including mTORC1. However, the metabolic processes governed by LAPTM4B and its role in oncogenesis remain unknown. In this study, we conducted unbiased metabolomic screens to uncover the metabolic landscape regulated by LAPTM4B. We observed common metabolic changes in several knockout cell models suggesting of a role for LAPTM4B in suppressing ferroptosis. Through a series of cell-based assays and animal experiments, we demonstrate that LAPTM4B protects tumor cells from erastin-induced ferroptosis both in vitro and in vivo. Mechanistically, LAPTM4B suppresses ferroptosis by inhibiting NEDD4L/ZRANB1 mediated ubiquitination and subsequent proteasomal degradation of the cystine-glutamate antiporter SLC7A11. Furthermore, metabolomic profiling of cancer cells revealed that LAPTM4B knockout leads to a significant enrichment of ferroptosis and associated metabolic alterations. By integrating results from cellular assays, patient tissue samples, an animal model, and cancer databases, this study highlights the clinical relevance of the LAPTM4B-SLC7A11-ferroptosis signaling axis in NSCLC progression and identifies it as a potential target for the development of cancer therapeutics.

A comparative review of adenovirus A12 and C5 oncogenes.

Oncogenic viruses contribute to 15% of global human cancers. To achieve that, virus-encoded oncoproteins deregulate cellular transcription, antagonize common cellular pathways, and thus drive cell transformation. Notably, adenoviruses were the first human viruses proven to induce cancers in diverse animal models. Over the past decades, human adenovirus (HAdV)-mediated oncogenic transformation has been pivotal in deciphering underlying molecular mechanisms. Key adenovirus oncoproteins, encoded in early regions 1 (E1) and 4 (E4), co-ordinate these processes. Among the different adenovirus species, the most extensively studied HAdV-C5 displays lower oncogenicity than HAdV-A12. A complete understanding of the different HAdV-A12 and HAdV-C5 oncoproteins in virus-mediated cell transformation, as summarized here, is relevant for adenovirus research and offers broader insights into viral transformation and oncogenesis.

hsa-miR-CHA2, a novel microRNA, exhibits anticancer effects by suppressing cyclin E1 in human non-small cell lung cancer cells.

Despite considerable therapeutic advancements, the global survival rate for lung cancer patients remains poor, posing challenges in developing an effective treatment strategy. In many cases, microRNAs (miRNAs) exhibit abnormal expression levels in cancers, including lung cancer. Dysregulated miRNAs often play a crucial role in the development and progression of cancer. Therefore, understanding the mechanisms underlying aberrant miRNA expression during carcinogenesis may provide crucial clues to develop novel therapeutics. In this study, we identified and cloned a novel miRNA, hsa-miR-CHA2, which is abnormally downregulated in non-small cell lung cancer (NSCLC)-derived cell lines and tissues of patients with NSCLC. Furthermore, we found that hsa-miR-CHA2 regulates the post-transcriptional levels of Cyclin E1 (CCNE1) by binding to the 3'-UTR of CCNE1 mRNA. CCNE1, a cell cycle regulator involved in the G1/S transition, is often amplified in various cancers. Notably, hsa-miR-CHA2 overexpression led to the alteration of the Rb-E2F pathway, a significant signaling pathway in the cell cycle, by targeting CCNE1 in A549 and SK-LU-1 cells. Subsequently, we confirmed that hsa-miR-CHA2 induced G1-phase arrest and exhibited an anti-proliferative effect by targeting CCNE1. Moreover, in subcutaneous xenograft mouse models, intra-tumoral injection of polyplexed hsa-miR-CHA2 mimic suppressed tumor growth and development. In conclusion, hsa-miR-CHA2 exhibited an anticancer effect by targeting CCNE1 both in vitro and in vivo. These findings suggest the potential role of hsa-miR-CHA2 as an important regulator of cell proliferation in molecular-targeted therapy for NSCLC.

The histological spectrum and immunoprofile of head and neck NUT carcinoma: A multicentre series of 30 cases.

BACKGROUND AND AIM: Head and neck nuclear protein of testis carcinoma (HN-NUT) is a rare form of carcinoma diagnosed by NUT immunohistochemistry positivity and/or NUTM1 translocation. Although the prototype of HN-NUT is a primitive undifferentiated round cell tumour (URC) with immunopositivity for squamous markers, it is our observation that it may assume variant histology or immunoprofile. METHODS: We conducted a detailed clinicopathological review of a large retrospective cohort of 30 HN-NUT, aiming to expand its histological and immunohistochemical spectrum. RESULTS: The median age of patients with HN-NUT was 39 years (range = 17-86). It affected the sinonasal tract (43%), major salivary glands (20%), thyroid (13%), oral cavity (7%), larynx (7%), neck (7%) and nasopharynx (3%). Although most cases of HN-NUT (63%) contained a component of primitive URC tumour, 53% showed other histological features and 37% lacked a URC component altogether. Variant histological features included basaloid (33%), differentiated squamous/squamoid (37%), clear cell changes (13%), glandular differentiation (7%) and papillary architecture (10%), which could co-exist. While most HN-NUT were positive for keratins, p63 and p40, occasional cases (5-9%) were entirely negative. Immunopositivity for neuroendocrine markers and thyroid transcription factor-1 was observed in 33 and 36% of cases, respectively. The outcome of HN-NUT was dismal, with a 3-year disease specific survival of 38%. CONCLUSIONS: HN-NUT can affect individuals across a wide age range and arise from various head and neck sites. It exhibits a diverse spectrum of histological features and may be positive for neuroendocrine markers, potentially leading to underdiagnosis. A low threshold to perform NUT-specific tests is necessary to accurately diagnose HN-NUT.

SP1-induced circ_0017552 modulates colon cancer cell proliferation and apoptosis via up-regulation of NET1.

Colon cancer (CC) is a common malignancy over the world and its morbidity and mortality significantly went up in China in recent years. Molecular functions in cancers have gradually been the pivot subject in cancer research. Neuroepithelial cell transforming 1 (NET1) was reported to contribute to prostate cancer and gastric cancer. Our study figured out that NET1 was overexpressed in CC cells. Then, loss-of-function assays revealed that NET1 facilitated CC cell proliferation and repressed CC cell apoptosis. Next, miR-338-3p was confirmed to target NET1. After that, we verified that circ_0017552 which originates from NET1 could positively modulate NET1 expression. Besides, circ_0017552 was a sponge of miR-338-3p. Rescue assays' results demonstrated that circ_0017552 could regulate CC cell proliferation and apoptosis through up-regulation of NET1. A transcription factor named Sp1 (SP1) was found to be present in circ_0017552. SP1 induced transcription of circ_0017552 to facilitate CC cell proliferation and inhibit CC cell apoptosis. In a word, SP1-induced circ_0017552 regulated CC cell proliferation and apoptosis through miR-338-3p/NET1 axis.

AURKB promotes colorectal cancer progression by triggering the phosphorylation of histone H3 at serine 10 to activate CCNE1 expression.

Aurora kinase B (AURKB) initiates the phosphorylation of serine 10 on histone H3 (pH3S10), a crucial process for chromosome condensation and cytokinesis in mammalian mitosis. Nonetheless, the precise mechanisms through which AURKB regulates the cell cycle and contributes to tumorigenesis as an oncogenic factor in colorectal cancer (CRC) remain unclear. Here, we report that AURKB was highly expressed and positively correlated with Ki-67 expression in CRC. The abundant expression of AURKB promotes the growth of CRC cells and xenograft tumors in animal model. AURKB knockdown substantially suppressed CRC proliferation and triggered cell cycle arrest in G2/M phase. Interestingly, cyclin E1 (CCNE1) was discovered as a direct downstream target of AURKB and functioned synergistically with AURKB to promote CRC cell proliferation. Mechanically, AURKB activated CCNE1 expression by triggering pH3S10 in the promoter region of CCNE1. Furthermore, it was showed that the inhibitor specific for AURKB (AZD1152) can suppress CCNE1 expression in CRC cells and inhibit tumor cell growth. To conclude, this research demonstrates that AURKB accelerated the tumorigenesis of CRC through its potential to epigenetically activate CCNE1 expression, suggesting AURKB as a promising therapeutic target in CRC.

Differential cyclin-E1 expression in CIC-rearranged sarcoma.

CIC-rearranged sarcoma (CRS) is a group of high-grade undifferentiated small round cell sarcomas examined as a separate entity in the current WHO classification; since it shows more aggressive clinical behavior and distinct morphological and molecular features compared to Ewing sarcoma (ES). As CCNE1 expression is associated with tumor growth in CIC::DUX4 sarcomas, we aimed to demonstrate the value of cyclin E1 expression in CRS. Cyclin E1 immunohistochemistry and break-apart FISH for EWSR1 and CIC gene rearrangements were performed on 3-mm tissue microarrays composed of 40 small round cell tumors. Five cases were classified as CRS, whereas 22 were ES and 13 were unclassified (EWSR1-/CIC-). Among all three diagnostic groups, we found cyclin E1 expression level to be higher in CRS (80 %) and unclassified groups (61.5 %) compared to ES (4.5 %, p < 0.001). In addition, high cyclin E1 expression levels were associated with higher mean age at diagnosis, presence of atypical histology and myxoid stroma, low CD99 expression, and presence of metastasis at diagnosis. The sensitivity and specificity of high cyclin E1 expression in detecting non-ES cases were 95.5 % and 66.7 %, respectively. However, the correlation between cyclin E1 expression level and survival was not statistically significant. This is the first study that shows cyclin E1 immunohistochemical expression in EWSR1-negative undifferentiated small cell sarcomas, particularly CRS.

AGR2-mediated unconventional secretion of 14-3-3ε and α-actinin-4, responsive to ER stress and autophagy, drives chemotaxis in canine mammary tumor cells.

BACKGROUND: Canine mammary tumors (CMTs) in intact female dogs provide a natural model for investigating metastatic human cancers. Our prior research identified elevated expression of Anterior Gradient 2 (AGR2), a protein disulfide isomerase (PDI) primarily found in the endoplasmic reticulum (ER), in CMT tissues, highly associated with CMT progression. We further demonstrated that increased AGR2 expression actively influences the extracellular microenvironment, promoting chemotaxis in CMT cells. Unraveling the underlying mechanisms is crucial for assessing the potential of therapeutically targeting AGR2 as a strategy to inhibit a pro-metastatic microenvironment and impede tumor metastasis. METHODS: To identify the AGR2-modulated secretome, we employed proteomics analysis of the conditioned media (CM) from two CMT cell lines ectopically expressing AGR2, compared with corresponding vector-expressing controls. AGR2-regulated release of 14-3-3ε (gene: YWHAE) and α-actinin 4 (gene: ACTN4) was validated through ectopic expression, knockdown, and knockout of the AGR2 gene in CMT cells. Extracellular vesicles derived from CMT cells were isolated using either differential ultracentrifugation or size exclusion chromatography. The roles of 14-3-3ε and α-actinin 4 in the chemotaxis driven by the AGR2-modulated CM were investigated through gene knockdown, antibody-mediated interference, and recombinant protein supplement. Furthermore, the clinical relevance of the release of 14-3-3ε and α-actinin 4 was assessed using CMT tissue-immersed saline and sera from CMT-afflicted dogs. RESULTS: Proteomics analysis of the AGR2-modulated secretome revealed increased abundance in 14-3-3ε and α-actinin 4. Ectopic expression of AGR2 significantly increased the release of 14-3-3ε and α-actinin 4 in the CM. Conversely, knockdown or knockout of AGR2 expression remarkably reduced their release. Silencing 14-3-3ε or α-actinin 4 expression diminished the chemotaxis driven by AGR2-modulated CM. Furthermore, AGR2 controls the release of 14-3-3ε and α-actinin 4 primarily via non-vesicular routes, responding to the endoplasmic reticulum (ER) stress and autophagy activation. Knockout of AGR2 resulted in increased α-actinin 4 accumulation and impaired 14-3-3ε translocation in autophagosomes. Depletion of extracellular 14-3-3ε or α-actinin 4 reduced the chemotaxis driven by AGR2-modulated CM, whereas supplement with recombinant 14-3-3ε in the CM enhanced the CM-driven chemotaxis. Notably, elevated levels of 14-3-3ε or α-actinin 4 were observed in CMT tissue-immersed saline compared with paired non-tumor samples and in the sera of CMT dogs compared with healthy dogs. CONCLUSION: This study elucidates AGR2's pivotal role in orchestrating unconventional secretion of 14-3-3ε and α-actinin 4 from CMT cells, thereby contributing to paracrine-mediated chemotaxis. The insight into the intricate interplay between AGR2-involved ER stress, autophagy, and unconventional secretion provides a foundation for refining strategies aimed at impeding metastasis in both canine mammary tumors and potentially human cancers.

The MYCN oncoprotein is an RNA-binding accessory factor of the nuclear exosome targeting complex.

The MYCN oncoprotein binds active promoters in a heterodimer with its partner protein MAX. MYCN also interacts with the nuclear exosome, a 3'-5' exoribonuclease complex, suggesting a function in RNA metabolism. Here, we show that MYCN forms stable high-molecular-weight complexes with the exosome and multiple RNA-binding proteins. MYCN binds RNA in vitro and in cells via a conserved sequence termed MYCBoxI. In cells, MYCN associates with thousands of intronic transcripts together with the ZCCHC8 subunit of the nuclear exosome targeting complex and enhances their processing. Perturbing exosome function results in global re-localization of MYCN from promoters to intronic RNAs. On chromatin, MYCN is then replaced by the MNT(MXD6) repressor protein, inhibiting MYCN-dependent transcription. RNA-binding-deficient alleles show that RNA-binding limits MYCN's ability to activate cell growth-related genes but is required for MYCN's ability to promote progression through S phase and enhance the stress resilience of neuroblastoma cells.

Characterization of cells expressing lipocalin-2 (LCN2) as a reporter.

Lipocalin-2 (LCN2), an effector molecule of the innate immune system that is small enough to be tagged as a reporter molecule, can be coupled with the ferric ion through a siderophore such as enterobactin (Ent). Mintbody (modification-specific intracellular antibody) can track a posttranslational protein modification in epigenetics. We constructed plasmids expressing the LCN2 hybrid of mintbody to examine the potential of LCN2 as a novel reporter for magnetic resonance imaging (MRI). Cells expressing the LCN2 hybrid of mintbody showed proper expression and localization of the hybrid and responded reasonably to Ent, suggesting their potential for in vivo study by MRI.

Multimodal Therapy Approaches for NUT Carcinoma by Dual Combination of Oncolytic Virus Talimogene Laherparepvec with Small Molecule Inhibitors.

NUT (nuclear-protein-in-testis) carcinoma (NC) is a highly aggressive tumor disease. Given that current treatment regimens offer a median survival of six months only, it is likely that this type of tumor requires an extended multimodal treatment approach to improve prognosis. In an earlier case report, we could show that an oncolytic herpes simplex virus (T-VEC) is functional in NC patients. To identify further combination partners for T-VEC, we have investigated the anti-tumoral effects of T-VEC and five different small molecule inhibitors (SMIs) alone and in combination in human NC cell lines. Dual combinations were found to result in higher rates of tumor cell reductions when compared to the respective monotherapy as demonstrated by viability assays and real-time tumor cell growth monitoring. Interestingly, we found that the combination of T-VEC with SMIs resulted in both stronger and earlier reductions in the expression of c-Myc, a main driver of NC cell proliferation, when compared to T-VEC monotherapy. These results indicate the great potential of combinatorial therapies using oncolytic viruses and SMIs to control the highly aggressive behavior of NC cancers and probably will pave the way for innovative multimodal clinical studies in the near future.