LINC00518: a key player in tumor progression and clinical outcomes.

Long non-coding RNAs (lncRNAs), defined as RNA molecules exceeding 200 nucleotides in length, have been implicated in the regulation of various biological processes and the progression of tumors. Among them, LINC00518, a recently identified lncRNA encoded by a gene located on chromosome 6p24.3, consists of three exons and is predicted to positively regulate the expression of specific genes. LINC00518 has emerged as a key oncogenic lncRNA in multiple cancer types. It exerts its tumor-promoting effects by modulating the expression of several target genes, primarily through acting as a sponge for microRNAs (miRNAs). Additionally, LINC00518 influences critical signaling pathways, including the Wnt/ß-catenin, JAK/STAT, and integrin ß3/FAK pathways. Elevated levels of LINC00518 in tumor tissues are associated with increased tumor size, advanced clinical stage, metastasis, and poor survival prognosis. This review provides a comprehensive summary of the genetic characteristics, expression patterns, biological functions, and underlying mechanisms of LINC00518 in human diseases.

Microbes for lung cancer detection: feasibility and limitations.

As the second most common cancer in the world, the development of lung cancer is closely related to factors such as heredity, environmental exposure, and lung microenvironment, etc. Early screening and diagnosis of lung cancer can be helpful for the treatment of patients. Currently, CT screening and histopathologic biopsy are widely used in the clinical detection of lung cancer, but they have many disadvantages such as false positives and invasive operations. Microbes are another genome of the human body, which has recently been shown to be closely related to chronic inflammatory, metabolic processes in the host. At the same time, they are important players in cancer development, progression, treatment, and prognosis. The use of microbes for cancer therapy has been extensively studied, however, the diagnostic role of microbes is still unclear. This review aims to summarize recent research on using microbes for lung cancer detection and present the current shortcomings of microbes in collection and detection. Finally, it also looks ahead to the clinical benefits that may accrue to patients in the future about screening and early detection.

The Role of CXCL11 and its Receptors in Cancer: Prospective but Challenging Clinical Targets.

Chemokine ligand 11 is a member of the CXC chemokine family and exerts its biological function mainly through binding to CXCR3 and CXCR7. The CXCL11 gene is ubiquitously overexpressed in various human malignant tumors; however, its specific mechanisms vary among different cancer types. Recent studies have found that CXCL11 is involved in the activation of multiple oncogenic signaling pathways and is closely related to tumorigenesis, progression, chemotherapy tolerance, immunotherapy efficacy, and poor prognosis. Depending on the specific expression of its receptor subtype, CXCL11 also has a complex 2-fold role in tumours; therefore, directly targeting the structure-function of CXCL11 and its receptors may be a challenging task. In this review, we summarize the biological functions of CXCL11 and its receptors and their roles in various types of malignant tumors and point out the directions for clinical applications.

CXCL11 is found in many types of cancer and affects how cancer cells grow and respond to treatments. This paper delves into the intricate dance between CXCL11 and its receptors in various types of cancer. Like a versatile actor playing different roles on stage, CXCL11 can either promote or hinder cancer growth depending on its interaction with specific receptors. Understanding how CXCL11 works could help develop new treatments for cancer, but it's a complex challenge because CXCL11 can have different effects depending on the type of cancer and which receptors it binds to.

Erratum: Thioredoxin 1 supports colorectal cancer cell survival and promotes migration and invasion under glucose deprivation through interaction with G6PD: Erratum.

[This corrects the article DOI: 10.7150/ijbs.71809.].

Auricular Vagal Nerve Stimulation Inhibited Central Nerve Growth Factor/Tropomyosin Receptor Kinase A/Phospholipase C-Gamma Signaling Pathway in Functional Dyspepsia Model Rats With Gastric Hypersensitivity.

OBJECTIVE: Functional dyspepsia (FD), which has a complicated pathophysiologic process, is a common functional gastrointestinal disease. Gastric hypersensitivity is the key pathophysiological factor in patients with FD with chronic visceral pain. Auricular vagal nerve stimulation (AVNS) has the therapeutic effect of reducing gastric hypersensitivity by regulating the activity of the vagus nerve. However, the potential molecular mechanism is still unclear. Therefore, we investigated the effects of AVNS on the brain-gut axis through the central nerve growth factor (NGF)/ tropomyosin receptor kinase A (TrkA)/phospholipase C-gamma (PLC-γ) signaling pathway in FD model rats with gastric hypersensitivity. MATERIALS AND METHODS: We established the FD model rats with gastric hypersensitivity by means of colon administration of trinitrobenzenesulfonic acid on ten-day-old rat pups, whereas the control rats were given normal saline. AVNS, sham AVNS, K252a (an inhibitor of TrkA, intraperitoneally), and K252a + AVNS were performed on eight-week-old model rats for five consecutive days. The therapeutic effect of AVNS on gastric hypersensitivity was determined by the measurement of abdominal withdrawal reflex response to gastric distention. NGF in gastric fundus and NGF, TrkA, PLC-γ, and transient receptor potential vanilloid 1 (TRPV1) in the nucleus tractus solitaries (NTS) were detected separately by polymerase chain reaction, Western blot, and immunofluorescence tests. RESULTS: It was found that a high level of NGF in gastric fundus and an upregulation of the NGF/TrkA/PLC-γ signaling pathway in NTS were manifested in model rats. Meanwhile, both AVNS treatment and the administration of K252a not only decreased NGF messenger ribonucleic acid (mRNA) and protein expressions in gastric fundus but also reduced the mRNA expressions of NGF, TrkA, PLC-γ, and TRPV1 and inhibited the protein levels and hyperactive phosphorylation of TrkA/PLC-γ in NTS. In addition, the expressions of NGF and TrkA proteins in NTS were decreased significantly after the immunofluorescence assay. The K252a + AVNS treatment exerted a more sensitive effect on regulating the molecular expressions of the signal pathway than did the K252a treatment. CONCLUSION: AVNS can regulate the brain-gut axis effectively through the central NGF/TrkA/PLC-γ signaling pathway in the NTS, which suggests a potential molecular mechanism of AVNS in ameliorating visceral hypersensitivity in FD model rats.

HMGA2 promotes nasopharyngeal carcinoma progression and is associated with tumor resistance and poor prognosis.

Nasopharyngeal carcinoma (NPC), as one of the most prevalent malignancies in the head and neck region, still lacks a complete understanding of its pathogenesis. Presently, radiotherapy, concurrent chemoradiotherapy, and targeted therapy stand as the primary modalities for treating NPC. With advancements in medicine, the cure rates for nasopharyngeal carcinoma have been steadily increasing. Nevertheless, recurrence and metastasis persist as the primary reasons for treatment failure. Consequently, a profound exploration of the molecular mechanisms underlying the occurrence and progression of nasopharyngeal carcinoma, along with the exploration of corresponding therapeutic approaches, becomes particularly imperative in the quest for comprehensive solutions to combat this disease. High mobility group AT-hook 2 (HMGA2) is a pivotal protein capable of altering chromatin structure, regulating gene expression, and influencing transcriptional activity. In the realm of cancer research, HMGA2 exhibits widespread dysregulation, playing a crucial role in nearly all malignant tumors. It is implicated in various tumorigenic processes, including cell cycle regulation, cell proliferation, epithelial-mesenchymal transition, angiogenesis, tumor invasion, metastasis, and drug resistance. Additionally, HMGA2 serves as a molecular marker and an independent prognostic factor in certain malignancies. Recent studies have increasingly unveiled the critical role of HMGA2 in nasopharyngeal carcinoma (NPC), particularly in promoting malignant progression, correlating with tumor resistance, and serving as an independent adverse prognostic factor. This review focuses on elucidating the oncogenic role of HMGA2 in NPC, suggesting its potential association with chemotherapy resistance in NPC, and proposing its candidacy as an independent factor in nasopharyngeal carcinoma prognosis assessment.

Thioredoxin 1 supports colorectal cancer cell survival and promotes migration and invasion under glucose deprivation through interaction with G6PD.

Overcoming energy stress is a critical step for cells in solid tumors. Under this stress microenvironment, cancer cells significantly alter their energy metabolism to maintain cell survival and even metastasis. Our previous studies have shown that thioredoxin-1 (Trx-1) expression is increased in colorectal cancer (CRC) and promotes cell proliferation. However, the exact role and mechanism of how Trx-1 is involved in energy stress are still unknown. Here, we observed that glucose deprivation of CRC cells led to cell death and promoted the migration and invasion, accompanied by upregulation of Trx-1. Increased Trx-1 supported CRC cell survival under glucose deprivation. Whereas knockdown of Trx-1 sensitized CRC cells to glucose deprivation-induced cell death and reversed glucose deprivation-induced migration, invasion, and epithelial-mesenchymal transition (EMT). Furthermore, we identified glucose-6-phosphate dehydrogenase (G6PD) interacting with Trx-1 by HuPortTM human protein chip, co-IP and co-localization. Trx-1 promoted G6PD protein expression and activity under glucose deprivation, thereby increasing nicotinamide adenine dinucleotide phosphate (NADPH) generation. Moreover, G6PD knockdown sensitized CRC cells to glucose deprivation-induced cell death and suppressed glucose deprivation-induced migration, invasion, and EMT. Inhibition of Trx-1 and G6PD, together with inhibition of glycolysis using 2-deoxy-D-glucose (2DG), resulted in significant anti-tumor effects in CRC xenografts in vivo. These findings demonstrate a novel mechanism and may represent a new effective therapeutic regimen for CRC.

DNA comethylation analysis reveals a functional association between BRCA1 and sperm DNA fragmentation.

OBJECTIVES: To identify the DNA comethylation patterns associated with sperm DNA fragmentation (SDF) and to explore the potential associations of hub genes with SDF. DESIGN: Prospective study. SETTING: University-affiliated reproductive medicine center. PATIENT(S): A total of 300 male patients consulting for couple infertility were recruited from the First Affiliated Hospital of Wenzhou Medical University. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Comethylation network analysis based on the genome-wide methylation profile of spermatozoal DNA from 20 men was performed to identify hub modules and genes involved in SDF. Human spermatozoa were used for targeted bisulfite amplicon sequencing (267 men) or droplet digital polymerase chain reaction (45 men). The potential role of Brca1 in DNA damage was explored in mouse GC2 spermatocyte cells. Oxidative damage to spermatocytes was modeled by incubating GC2 cells with H2O2 (25 mM) for 90 minutes. RESULT(S): BRCA1 was identified as a hub gene in SDF. Promoter hypermethylation of BRCA1 was observed in those samples with a high DNA fragmentation index (DFI) compared to those with a low DFI. Concomitantly, BRCA1 mRNA expression was lower in samples with a high DFI than with a low DFI. In the GC2 cell model, Brca1 knockdown reduced cell proliferation and increased sensitivity to oxidative stress. Moreover, it increased double-strand breaks and decreased the protein levels of the DNA repair genes MRE11 and RAD51. CONCLUSION(S): A prominent cluster of comethylated patterns associated with SDF was identified. BRCA1 may be the hub gene involved in sperm DNA damage.

Short-term changes in and preoperative factors affecting vaulting after posterior chamber phakic Implantable Collamer Lens implantation.

BACKGROUND: To describe the very early vault changes in the first month after Implantable Collamer Lens (ICL) implantation and to evaluate the effect of preoperative biometric factors on vault. METHODS: Eighty-three eyes from eighty-three subjects with complete data who met follow-up requirements were recruited in this retrospective study between May 2019 and March 2020. We quantitatively assessed the postoperative vault at 2 h, 1 day, 1 week, and 1 month following implantation. Associations between the postoperative vault and age, ICL size, spherical equivalent (SE), axial length (AL), central corneal thickness (CCT), flat keratometry (K), steep K, mean K, anterior chamber depth (ACD), crystalline lens thickness (LT), white-to-white (WTW) diameter obtained by three devices, horizontal and vertical sulcus-to-sulcus (STS) diameter, bright and dark pupil sizes (BPS and DPS) and DPS-BPS were investigated using Spearman's correlation analysis and stepwise multiple regression analysis. RESULTS: The mean vault values at 2 h, 1 day, 1 week, and 1 month after ICL implantation were 672.05 ± 30.72, 389.15 ± 28.33, 517.23 ± 30.76 and 530.12 ± 30.22 µm, respectively. Significant differences were found in the vault values at 2 h, 1 day and 1 week after the operation. The ICL size (ß = 0.942; p < 0.001), followed by horizontal STS (ß = -0.517; p < 0.001), crystalline LT (ß = -0.376; p < 0.001) and vertical STS (ß = -0.257; p = 0.017), significantly influenced the vault at 1 month after the operation. The multiple regression equation was expressed as follows: central vault (µm) = -1369.05 + 657.121 × ICL size- 287.408 × horizontal STS - 432.497 × crystalline LT - 137.33 × vertical STS (adjusted R2 = 0.643). CONCLUSIONS: After ICL implantation, the vault decreased and then increased, but it did not return to the vault value 2 h after surgery. The ICL size, horizontal and vertical STS and crystalline LT are key factors for predicting postoperative vaulting.

Exosome-transmitted miRNA-335-5p promotes colorectal cancer invasion and metastasis by facilitating EMT via targeting RASA1.

Exosomal microRNA (miRNA) secretion has been characterized as a vital factor in intercellular communication among cancer cells. However, little is known about cancer-secreted miRNAs specifically involved in metastasis of colorectal cancer (CRC). Here, we found that exosomes derived from metastatic CRC cell line SW620 promoted migration, invasion, and epithelial-mesenchymal transition (EMT) of CRC cells. The profiling of exosome miRNAs revealed that microRNA (miR)-335-5p was highly expressed in exosomes from metastatic SW620 cells compared to those derived from primary SW480 cells. miR-335-5p was transmitted from metastatic SW620 cells to CRC cells via exosomes and promoted migration, invasion, and EMT of CRC cells. Moreover, exosome-transmitted miRNA-335-5p promotes CRC cell invasion and metastasis by facilitating EMT via targeting RAS p21 protein activator 1 (RASA1). Overexpression of RASA1 abolished the promotive effects of exosomal miR-335-5p on CRC cell migration, invasion, and EMT. Collectively, our data revealed that exosomal miR-335-5p derived from metastatic CRC cells promotes CRC cell invasion and metastasis by facilitating EMT via targeting RASA1, which may serve as a potential therapeutic target for CRC metastasis.

BCAT1 decreases the sensitivity of cancer cells to cisplatin by regulating mTOR-mediated autophagy via branched-chain amino acid metabolism.

Cisplatin is one of the most effective chemotherapy drugs and is widely used in the treatment of cancer, including hepatocellular carcinoma (HCC) and cervical cancer, but its therapeutic benefit is limited by the development of resistance. Our previous studies demonstrated that BCAT1 promoted cell proliferation and decreased cisplatin sensitivity in HCC cells. However, the exact role and mechanism of how BCAT1 is involved in cisplatin cytotoxicity remain undefined. In this study, we revealed that cisplatin triggered autophagy in cancer cells, with an increase in BCAT1 expression. The cisplatin-induced up-regulation of BCAT1 decreased the cisplatin sensitivity by regulating autophagy through the mTOR signaling pathway. In addition, branched-chain amino acids or leucine treatment inhibited cisplatin- or BCAT1-mediated autophagy and increased cisplatin sensitivity by activating mTOR signaling in cancer cells. Moreover, inhibition of autophagy by chloroquine increased cisplatin sensitivity in vivo. Also, the knockdown of BCAT1 or the administration of leucine activated mTOR signaling, inhibited autophagy, and increased cisplatin sensitivity in cancer cells in vivo. These findings demonstrate a new mechanism, revealing that BCAT1 decreases cisplatin sensitivity in cancer cells by inducing mTOR-mediated autophagy via branched-chain amino acid leucine metabolism, providing an attractive pharmacological target to improve the effectiveness of chemotherapy.

WT1 facilitates the self-renewal of leukemia-initiating cells through the upregulation of BCL2L2: WT1-BCL2L2 axis as a new acute myeloid leukemia therapy target.

BACKGROUND: Overexpression of Wilms' tumor-1 (WT1) transcription factor facilitates proliferation in acute myeloid leukemia (AML). However, whether WT1 is enriched in the leukemia-initiating cells (LICs) and leukemia stem cells (LSCs) and facilitates the self-renewal of LSCs remains poorly understood. METHODS: MLL-AF9-induced murine leukemia model was used to evaluate the effect of knockdown of wt1 on the self-renewal ability of LSC. RNA sequencing was performed on WT1-overexpressing cells to select WT1 targets. Apoptosis and colony formation assays were used to assess the anti-leukemic potential of a deubiquitinase inhibitor WP1130. Furthermore, NOD/SCID-IL2Rγ (NSG) AML xenotransplantation and MLL-AF9-induced murine leukemia models were used to evaluate the anti-leukemogenic potential of WP1130 in vivo. RESULTS: We found that wt1 is highly expressed in LICs and LSCs and facilitates the maintenance of leukemia in a murine MLL-AF9-induced model of AML. WT1 enhanced the self-renewal of LSC by increasing the expression of BCL2L2, a member of B cell lymphoma 2 (BCL2) family, by direct binding to its promoter region. Loss of WT1 impaired self-renewal ability in LSC and delayed the progression of leukemia. WP1130 was found to modify the WT1-BCL2L2 axis, and WP1130-induced anti-leukemic activity was mediated by ubiquitin proteasome-mediated destruction of WT1 protein. WP1130 induced apoptosis and decreased colony formation abilities of leukemia cells and prolonged the overall survival in the THP1-based xenograft NSG mouse model. WP1130 also decreased the frequency of LSC and prolonged the overall survival in MLL-AF9-induced murine leukemia model. Mechanistically, WP1130 induced the degradation of WT1 by positively affecting the ubiquitination of WT1 protein. CONCLUSIONS: Our results indicate that WT1 is required for the development of AML. WP1130 exhibits anti-leukemic activity by inhibiting the WT1-BCL2L2 axis, which may represent a new acute myeloid leukemia therapy target.

Deubiquitinase inhibitor degrasyn suppresses metastasis by targeting USP5-WT1-E-cadherin signalling pathway in pancreatic ductal adenocarcinoma.

Wilm's tumour-1 (WT1) is overexpressed in pancreatic ductal adenocarcinoma (PDAC) and enhances metastasis. Deubiquitination stabilizes target proteins, and inhibiting deubiquitination facilitates the degradation of target proteins. However, whether inhibiting deubiquitination of WT1 facilitates its degradation and presents anti-cancer ability in PDAC is unknown. Here, we found that deubiquitinase inhibitor degrasyn rapidly induced the degradation of endogenous and exogenous WT1 through enhancing ubiquitination of WT1 followed by the up-regulation of E-cadherin. Knockdown of WT1 by short hairpin RNAs (shRNAs) inhibited metastasis and overexpression of WT1 partially prevented degrasyn-induced anti-metastasis activity, suggesting that degrasyn presents anti-metastasis activity partially through degrading WT1 protein. We further identified that USP5 deubiquitinated WT1 and stabilized its expression. The higher expressions of USP5 and WT1 are associated with tumour metastasis. More importantly, degrasyn inhibited the activity of USP5 and overexpression of USP5 partially prevented degrasyn-induced degradation of WT1 protein, suggesting that degrasyn degraded WT1 protein through inhibiting the activity of USP5. Finally, degrasyn reduced the tumorigenicity in a xenograft mouse model and reduced the metastasis in vivo. Our results indicate that degrasyn presents strong anti-cancer activity through USP5-WT1-E-cadherin signalling in PDAC. Therefore, degrasyn holds promise as cancer therapeutic agent in PDAC with high expressions of USP5 and WT1.

Prognostic Potential of Alternative Splicing Markers in Endometrial Cancer.

Alternative splicing (AS), an important post-transcriptional regulatory mechanism that regulates the translation of mRNA isoforms and generates protein diversity, has been widely demonstrated to be associated with oncogenic processes. In this study, we systematically analyzed genome-wide AS patterns to explore the prognostic implications of AS in endometrial cancer (EC). A total of 2,324 AS events were identified as being associated with the overall survival of EC patients, and eleven of these events were further selected using a random forest algorithm. With the implementation of a generalized, boosted regression model, a prognostic AS model that aggregated these eleven markers was ultimately established with high performance for risk stratification in EC patients. Functional analysis of these eleven AS markers revealed various potential signaling pathways implicated in the progression of EC. Splicing network analysis demonstrated the notable correlation between the expression of splicing factors and AS markers in EC and further determined eight candidate splicing factors that could be therapeutic targets for EC. Taken together, the results of this study present the utility of AS profiling in identifying biomarkers for the prognosis of EC and provide comprehensive insight into the molecular mechanisms involved in EC processes.

Primary thyroid spindle cell tumors: spindle cell variant of papillary thyroid carcinoma?

Primary thyroid spindle cell tumors or spindle cell component in the thyroid tumors are very rare. The spindle tumor cells were positive for thyroid papillary carcinoma markers. So these tumors were diagnosed as spindle cell variant of papillary thyroid carcinoma (PTC). To further delineate clinico-pathological features of primary thyroid spindle cell tumors and discuss differential diagnosis, we reported a 67-year-old man with a mass in the right thyroid without clinical symptom. Microscopy revealed that an encapsulated tumor with lot criss spindle cells arranged in bundles. Nuclear grooves were easy to see and rare displayed pseudoinclusions. Immunohistochemical studied showed that the spindle cells were all strong positive for TTF-1, Pax-8, thyroglobulin. Rare follicular were seen in the periphery of the tumor near the thyroid tissue. The cells formed follicular but the spindle tumor cells were positive for pan-keratins. The pathological diagnosis was primary thyroid spindle cell tumors, suspected spindle cell variant of PTC. Primary thyroid spindle cell tumors were presence and without the unified name. The further reports and more discussion were need about these tumors.

A 25-year-old woman with a mass in the hippocampus.

Angiocentric gliomas (AG) have only recently been described. We encountered a 25-year-old woman with AG who had a history of epilepsy for two years. MRI revealed that there was a solid tumor in the hippocampus. The tumor was totally removed. Histologically, the spindle tumor cells proliferated around small parenchymal vessels with perivascular pseudorosettes. The tumor cells of the hippocampus surface umbilicated forming rosettes. Immunohistochemistry demonstrated positivity for GFAP, Vimentin and S-100, but were negative for neurofilament protein, Syn, CgA and P53. EMA had "dot-like" positive staining. The proliferation index was less than 1%. The location of the tumor and the pathological findings confirm that the diagnose was AG. Epilepsy disappeared after the operation. When fully resected these tumors have a good prognosis.

A histologically defined subset of high-grade dysplasia in Barrett mucosa is predictive of associated carcinoma.

To ascertain the prevalence of carcinoma in esophagi resected for high-grade dysplasia (HGD) using current criteria and to evaluate histologic features that may predict concurrent carcinoma, we studied specimens from 127 esophagectomies performed for HGD, or HGD "suspicious" for carcinoma (HGD/S) in Barrett mucosa. Corresponding biopsy specimens in 69 cases were reviewed and reclassified. Based on original diagnoses, carcinoma was present in 15 (17%) of 89 HGD and 28 (74%) of 38 HGD/S cases. By reclassification, only 1 (5%) of 21 cases with HGD had carcinoma in the resection specimen. Of 25 cases reclassified as HGD/S, 18 (72%) had carcinoma in the resection specimen, as did 17 (74%) of 23 reclassified as adenocarcinoma. With 1 additional select histologic feature, the risk of carcinoma was 39%; with 2 or more features, the risk increased to 83% to 88%. Based on current criteria, no more than 5% of esophagectomies performed for a biopsy diagnosis of Barrett HGD harbor carcinoma. When HGD/S is diagnosed based on certain additional features, carcinoma is found in nearly 40% of cases with 1 feature and more than 80% with 2 or more features. Our findings highlight the evolution of diagnostic criteria for Barrett dysplasia.

WT1, monoclonal CEA, TTF1, and CA125 antibodies in the differential diagnosis of lung, breast, and ovarian adenocarcinomas in serous effusions.

The distinction between metastatic adenocarcinomas of lung (LAC), breast (BAC), and ovary (OAC) in serous effusions can be very difficult since they all can present as tight cell clusters. This is particularly challenging when the malignant effusion is the patient's initial presentation or when the patient has a history of more than one primary. The aim of this study is to evaluate the usefulness of WT1, monoclonal CEA (mCEA), TTF1, and CA125 antibodies in the differential diagnosis of metastatic adenocarcinoma from the lung, breast and ovary in serous effusions. Forty-six samples of serous effusions with their corresponding cell blocks were retrieved from our hospital computer system, including 13 BACs, 13 LACs, and 20 OACs. The diagnoses were confirmed by the surgical resection. Formalin-fixed and paraffin-embedded cell block sections were immunostained for WT1, mCEA, TTF1, and CA125. Two observers blindly reviewed the immunostained slides without knowledge of the previous clinical or histologic diagnoses. The staining intensity was graded semiquantitatively as negative, 0; weak, 1+; moderate, 2+; and strong, 3+. The percentage of positively staining cells was estimated. The distribution patterns of reactivity for WT1 and TTF1 were recorded as nuclear, and mCEA and CA125 as membranous stain. Metastatic OACs showed positive immunoreactivity to WT1 in 19/20 (95%) cases, CA125 in 20/20 (100%), and all showed negative reaction for both mCEA (0/20, 0%) and TTF1 (0/20, 0%). BAC showed positive reaction in 6/13 (46%) cases to CA125 and mCEA. Staining pattern was diffuse for CA125 and focal for mCEA. Only 2/13 (15%) were positive for WT1, while all of 13 BAC cases (0/13, 0%) were negative for TTF1. LAC showed positive immunoreactivity for TTF1 in 9/13 (69%) with a characteristic nuclear staining pattern, but only 3/13 (23%) were focally stained for WT1. In addition, 8/13 (62%) of LAC cases were positive for both CA125 and mCEA. Our results demonstrate that the WT1 stain is specific for metastatic carcinoma of ovarian primary, showing a high sensitivity. In addition, CA125 stain is very sensitive for OACs, but could be positive in about a half of LAC and BAC cases. An immunostaining pattern of positive mCEA as well as negative WT1 rules out OACs, raising the possibility of LACs and BACs. A positive TTF1 staining supports the diagnosis of metastatic carcinoma originating from lung rather than breast, while a negative TTF1 favors the diagnosis of a breast primary. Immunohistochemical studies with WT1, TTF1, and mCEA antibodies are useful in the differential diagnosis of metastatic adenocarcinomas of lung, breast, and ovary.