Molecular characteristics of tubo-ovarian carcinosarcoma at different anatomic locations.

Carcinosarcoma (CS) is an uncommon and clinically aggressive malignancy. The objective of the present study was to characterize the molecular features of CS at various anatomic locations, including serous effusions. Specimens (n = 32) consisted of 25 biopsies/surgical resection specimens and 7 serous effusions (6 peritoneal, 1 pleural) from 25 patients. Fresh-frozen cell pellets and surgical specimens underwent targeted next-generation sequencing covering 50 unique genes. A total of 31 mutations were found in 25 of the 32 tumors studied, of which 1 had 3 mutations, 4 had 2 different mutations, and 20 had a single mutation. The most common mutations were in TP53 (n = 25 in 24 tumors; 1 tumor with 2 different mutations), with less common mutations found in RB1 (n = 2), MET (n = 1), KRAS (n = 1), PTEN (n = 1), and KIT (n = 1). Patient-matched specimens harbored the same TP53 mutation. Tumors with no detected mutations were more common in serous effusion specimens (3/7; 43%) compared with surgical specimens (4/25; 16%). In conclusion, the molecular landscape of CS is dominated by TP53 mutations, reinforcing the observation that the majority of these tumors develop from high-grade serous carcinoma. Whether CS cells in serous effusions differ from their counterparts in solid lesions remains uncertain.

Efficient CAR T cell targeting of the CA125 extracellular repeat domain of MUC16.

BACKGROUND: Ovarian cancer (OC) is the leading cause of death from gynecologic malignancies in the Western world. Contributing factors include a high frequency of late-stage diagnosis, the development of chemoresistance, and the evasion of host immune responses. Currently, debulking surgery and platinum-based chemotherapy are the treatment cornerstones, although recurrence is common. As the clinical efficacy of immune checkpoint blockade is low, new immunotherapeutic strategies are needed. Chimeric antigen receptor (CAR) T cell therapy empowers patients' own T cells to fight and eradicate cancer, and has been tested against various targets in OC. A promising candidate is the MUC16 ectodomain. This ectodomain remains on the cell surface after cleavage of cancer antigen 125 (CA125), the domain distal from the membrane, which is currently used as a serum biomarker for OC. CA125 itself has not been tested as a possible CAR target. In this study, we examined the suitability of the CA125 as a target for CAR T cell therapy. METHODS: We tested a series of antibodies raised against the CA125 extracellular repeat domain of MUC16 and adapted them to the CAR format. Comparisons between these candidates, and against an existing CAR targeting the MUC16 ectodomain, identified K101 as having high potency and specificity. The K101CAR was subjected to further biochemical and functional tests, including examination of the effect of soluble CA125 on its activity. Finally, we used cell lines and advanced orthotopic patient-derived xenograft (PDX) models to validate, in vivo, the efficiency of our K101CAR construct. RESULTS: We observed a high efficacy of K101CAR T cells against cell lines and patient-derived tumors, in vitro and in vivo. We also demonstrated that K101CAR functionality was not impaired by the soluble antigen. Finally, in direct comparisons, K101CAR, which targets the CA125 extracellular repeat domains, was shown to have similar efficacy to the previously validated 4H11CAR, which targets the MUC16 ectodomain. CONCLUSIONS: Our in vitro and in vivo results, including PDX studies, demonstrate that the CA125 domain of MUC16 represents an excellent target for treating MUC16-positive malignancies.

Evolutionary mode and timing of dissemination of high-grade serous carcinomas.

Dissemination within the peritoneal cavity is a main determinant of poor patient outcomes from high-grade serous carcinomas (HGSCs). The dissemination process is poorly understood from a cancer evolutionary perspective. We reconstructed the evolutionary trajectories across a median of 5 tumor sites and regions from each of 23 patients based on deep whole-exome sequencing. Polyclonal cancer origin was detected in 1 patient. Ovarian tumors had more complex subclonal architectures than other intraperitoneal tumors in each patient, which indicated that tumors developed earlier in the ovaries. Three common modes of dissemination were identified, including monoclonal or polyclonal dissemination of monophyletic (linear) or polyphyletic (branched) subclones. Mutation profiles of initial or disseminated clones varied greatly among cancers, but recurrent mutations were found in 7 cancer-critical genes, including TP53, BRCA1, BRCA2, and DNMT3A, and in the PI3K/AKT1 pathway. Disseminated clones developed late in the evolutionary trajectory models of most cancers, in particular in cancers with DNA damage repair deficiency. Polyclonal dissemination was predicted to occur predominantly as a single and rapid wave, but chemotherapy exposure was associated with higher genomic diversity of disseminated clones. In conclusion, we described three common evolutionary dissemination modes across HGSCs and proposed factors associated with dissemination diversity.

Molecular features for timely cancer diagnosis and treatment - tumors of the ovary, fallopian tube and endometrium.

Gynecologic pathology has moved, within only a few years, from being a diagnostic area devoid of molecular testing into a diagnostic discipline in which such analyses are becoming routine. The direct relevance of molecular characterization to the choice of treatment of patients with carcinomas originating in both the uterus and adnexae makes it likely that such testing will only expand along with our understanding of the molecular make-up of these tumors. As a consequence, gynecologic pathologists have become an integral part of patient management, rather than lab personnel providing external services.In parallel, molecular testing is expanding as a tool for diagnosing rare tumors affecting these organs, including soft tissue tumors, sex cord-stromal tumors and germ cell tumors, as well as other rare entities. Increased knowledge in this area bears directly on the ability to diagnose these tumors in a reproducible manner, as well as recognize and consult on genetic diseases. Hopefully, despite the inherent difficulty in studying rare cancers, it will also translate into new therapeutic options for the malignant ones among these rare cancers.

Endometrial Pipelle Biopsy Computer-Aided Diagnosis: A Feasibility Study.

Endometrial biopsies are important in the diagnostic workup of women who present with abnormal uterine bleeding or hereditary risk of endometrial cancer. In general, approximately 10% of all endometrial biopsies demonstrate endometrial (pre)malignancy that requires specific treatment. As the diagnostic evaluation of mostly benign cases results in a substantial workload for pathologists, artificial intelligence (AI)-assisted preselection of biopsies could optimize the workflow. This study aimed to assess the feasibility of AI-assisted diagnosis for endometrial biopsies (endometrial Pipelle biopsy computer-aided diagnosis), trained on daily-practice whole-slide images instead of highly selected images. Endometrial biopsies were classified into 6 clinically relevant categories defined as follows: nonrepresentative, normal, nonneoplastic, hyperplasia without atypia, hyperplasia with atypia, and malignant. The agreement among 15 pathologists, within these classifications, was evaluated in 91 endometrial biopsies. Next, an algorithm (trained on a total of 2819 endometrial biopsies) rated the same 91 cases, and we compared its performance using the pathologist's classification as the reference standard. The interrater reliability among pathologists was moderate with a mean Cohen's kappa of 0.51, whereas for a binary classification into benign vs (pre)malignant, the agreement was substantial with a mean Cohen's kappa of 0.66. The AI algorithm performed slightly worse for the 6 categories with a moderate Cohen's kappa of 0.43 but was comparable for the binary classification with a substantial Cohen's kappa of 0.65. AI-assisted diagnosis of endometrial biopsies was demonstrated to be feasible in discriminating between benign and (pre)malignant endometrial tissues, even when trained on unselected cases. Endometrial premalignancies remain challenging for both pathologists and AI algorithms. Future steps to improve reliability of the diagnosis are needed to achieve a more refined AI-assisted diagnostic solution for endometrial biopsies that covers both premalignant and malignant diagnoses.

Occludin is overexpressed in tubo-ovarian high-grade serous carcinoma compared to mesothelioma and is a marker of tumor progression and chemoresistance.

The objective of this study was to analyze the expression and prognostic role of the tight junction protein occludin in high-grade serous carcinoma (HGSC). Occludin protein expression by immunohistochemistry was analyzed in 602 HGSC (417 effusions, 185 surgical specimens). Expression in mesothelioma (n = 87; 45 effusions, 42 surgical specimens) was studied for comparative purposes. Occludin protein expression was found in 587/602 (98%) HGSC vs. 40/87 (46%) mesotheliomas and was predominantly limited to < 5% of cells in the latter (p < 0.001). Occludin was additionally overexpressed in HGSC effusions compared to surgical specimens (p < 0.001) and was overexpressed in post-chemotherapy effusions compared to chemo-naive effusions tapped at diagnosis (p = 0.015). Occludin expression in HGSC surgical specimens was associated with poor chemoresponse (p < 0.001) and primary resistance (p = 0.001). Expression in effusions and surgical specimens was unrelated to survival (p > 0.05). In conclusion, occludin expression is higher in HGSC compared to mesothelioma, and this protein is overexpressed in HGSC effusions, possibly reflecting changes in adhesion related to anchorage-independent growth in this microenvironment. Overexpression in post-chemotherapy compared to chemo-naïve effusions suggest a role in disease progression. Occludin expression in surgical specimens may be related to chemoresistance.

Lymphovascular invasion and p16 expression are independent prognostic factors in stage I vulvar squamous cell carcinoma.

The objective of this study was to identify clinicopathologic parameters associated with disease outcome in FIGO stage I vulvar squamous cell carcinoma (vSqCC). The cohort consisted of 126 patients diagnosed with vSqCC in the period 2006-2016 who underwent primary vulvar surgery and evaluation of groin lymph node status. Tumors were reviewed by an experienced gynecologic pathologist. p16 and p53 protein expression by immunohistochemistry and HPV status were analyzed in 116 tumors. Clinicopathologic parameters, protein expression and HPV status were analyzed for association with progression-free and overall survival (PFS, OS). p16 expression and aberrant p53 were found in 49 (42%) and 61 (53%) tumors, respectively. Sixty-six tumors were HPV-associated (57%). Relapse was diagnosed in 35/126 (28%) of patients, and 23 (18%) died of disease. Tumor diameter > 4 cm (p = 0.013), lymphovascular space invasion (LVSI; p < 0.001), the presence of lichen sclerosus (p = 0.019), p16 expression (p = 0.007), p53 expression (p = 0.012), HPV status (p = 0.021), lymph node metastasis (p < 0.001) and post-operative radiotherapy (p < 0.001) were significantly related to OS in univariate analysis. Tumor diameter > 4 cm (p = 0.038), LVSI (p = 0.003), the presence of lichen sclerosus (p = 0.004), p16 expression (p = 0.004), HPV status (p = 0.039), lymph node metastasis (p < 0.001) and post-operative treatment (p < 0.001), were significantly related to PFS in univariate analysis. Age, BMI and surgical resection involvement were not significantly associated with OS or PFS. In multivariate Cox analysis, LVSI and p16 expression were independent prognosticators of OS (p < 0.001 and p = 0.02, respectively) and PFS (p = 0.018, p = 0.037). In conclusion, LVSI and p16 expression are independent prognostic factors in stage I vSqCC.

Genetic Pathways in Peritoneal Mesothelioma Tumorigenesis.

BACKGROUND/AIM: Mesotheliomas are tumors similar to, and probably derived from, mesothelial cells. They carry acquired chromosomal rearrangements, deletions affecting CDKN2A, pathogenetic polymorphisms in NF2, and fusion genes which often contain the promiscuous EWSR1, FUS, and ALK as partner genes. Here, we report the cytogenomic results on two peritoneal mesotheliomas. MATERIALS AND METHODS: Both tumors were examined using G-banding with karyotyping and array comparative genomic hybridization (aCGH). One of them was further investigated with RNA sequencing, reverse transcription polymerase chain reaction (RT-PCR), Sanger sequencing, and fluorescence in situ hybridization (FISH). RESULTS: In the first mesothelioma, the karyotype was 25∼26,X,+5,+7,+20[cp4]/50∼52,idemx2[cp7]/46,XX[2]. aCGH detected gains of chromosomes 5, 7, and 20 with retained heterozygosity on these chromosomes. In the second tumor, the karyotype was 46,XX,inv(10)(p11q25)[7]/46,XX[3]. aCGH did not detect any gains or losses and showed heterozygosity for all chromosomes. RNA sequencing, RT-PCR/Sanger sequencing, and FISH showed that the inv(10) fused MAP3K8 from 10p11 with ABLIM1 from 10q25. The MAP3K8::ABLIM1 chimera lacked exon 9 of MAP3K8. CONCLUSION: Our data, together with information on previously described mesotheliomas, illustrate two pathogenetic mechanisms in peritoneal mesothelioma: One pathway is characterized by hyperhaploidy, but with retained disomies for chromosomes 5, 7, and 20; this may be particularly prevalent in biphasic mesotheliomas. The second pathway is characterized by rearrangements of MAP3K8 from which exon 9 of MAP3K8 is lost. The absence of exon 9 from oncogenetically rearranged MAP3K8 is a common theme in thyroid carcinoma, lung cancer, and spitzoid as well as other melanoma subtypes.

Clinical significance of L1CAM expression in metastatic tubo-ovarian high-grade serous carcinoma.

OBJECTIVE: To analyze the expression and prognostic role of L1CAM in tubo-ovarian high-grade serous carcinoma (HGSC). METHODS: L1CAM protein expression by immunohistochemistry was analyzed in 644 HGSC (413 effusions, 231 surgical specimens). Expression was analyzed for association with clinicopathologic parameters and survival. RESULTS: L1CAM protein expression was found in 401/413 (97%) effusions and 209/231 (90%) surgical specimens, with significantly higher staining extent in effusions (p < 0.001). L1CAM protein expression in effusions was unrelated to clinicopathologic parameters (p > 0.05). In surgical specimens, higher L1CAM expression was significantly related to primary (intrinsic) chemoresistance (p = 0.017). High (>25%) L1CAM expression in HGSC effusions (p = 0.02), older patient age (p = 0.013), FIGO stage IV disease (p < 0.001) and larger residual disease volume (p = 0.001) were significantly associated with shorter overall survival (OS) in univariate analysis. In Cox multivariate analysis, only FIGO stage (p = 0.001) and residual disease volume (p = 0.003) were independent prognosticators of OS. L1CAM expression in effusions was unrelated to progression-free survival (PFS). There was no association between L1CAM expression in surgical specimens and survival. CONCLUSION: L1CAM is overexpressed in HGSC effusions compared to surgical specimens. Its overexpression in effusions is significantly associated with shorter OS, but not independently of established prognostic factors such as FIGO stage and residual disease volume.

Cancer Stem Cell Markers Are Differentially Expressed in Malignant Ovarian Germ Cell Tumors.

The objective of this study was to analyze the expression and potential clinical role of cancer stem cell (CSC) markers in malignant ovarian germ cell tumors (MOGCT). CD34, CD44, and SOX2 protein expression by immunohistochemistry was analyzed in 49 MOGCT from patients treated in Norway during the period 1980-2011. Expression was analyzed for association with tumor type and clinicopathologic parameters. Tumors were diagnosed as dysgerminoma (DG; n=15), immature teratoma (IT; n=15), yolk sac tumor (YST; n=12), embryonal carcinoma (n=2), and mixed MOGCT (n=5). Tumor cell CD34 expression was significantly more common in YST, whereas stromal expression was only seen in IT (both P <0.001). CD44 was infrequently expressed, most often focally, in tumor cells, particularly in YST ( P =0.026). CD44 was widely expressed in leukocytes, most prominently in DG. SOX2 was most frequently expressed in IT, with predominantly focal expression in some YST and uniform absence in DG ( P <0.001). Stromal CD34 ( P =0.012) and tumor cell SOX2 expression ( P =0.004) were negatively associated with the involvement of the ovarian surface, presumably due to the low incidence of this event in IT. No significant association was found between CSC marker expression and other clinicopathologic parameters, including age, laterality, tumor diameter, and FIGO stage. In conclusion, CSC markers are differentially expressed in various MOGCT types, suggesting differences in the regulation of cancer-related processes. Expression of CD34, CD44, and SOX2 does not appear to be associated with clinical parameters in this patient group.

Claudin-10 is a new candidate prognostic marker in metastatic high-grade serous carcinoma.

The objective of this study was to analyze the expression and prognostic role of the tight junction protein claudin-10 in high-grade serous carcinoma (HGSC). Claudin-10 protein expression by immunohistochemistry was analyzed in 588 HGSC (414 effusions, 174 surgical specimens). Expression in mesotheliomas (n = 97; 47 effusions, 50 surgical specimens) was studied for comparative purposes. CLDN10 mRNA expression by quantitative RT-PCR (qRT-PCR) was analyzed in 40 HGSC effusions. Claudin-10 protein expression was found in 360/588 (61%) HGSC vs. 19/97 (20%) mesotheliomas (p < 0.001), and was higher in HGSC surgical specimens compared to effusions (p < 0.001). qRT-PCR confirmed the presence of CLDN10 mRNA in HGSC effusions. High (> 25%) claudin-10 expression in HGSC effusions was significantly associated with shorter overall survival (OS; p = 0.036) and progression-free survival (PFS; p = 0.045) in univariate analysis, and was an independent prognosticator of OS in multivariate analysis (p = 0.045). In conclusion, claudin-10 protein expression is higher in HGSC compared to mesothelioma, although the diagnostic power of this marker appear to be lesser than other claudin family members. Claudin-10 expression in HGSC effusions is marker of more aggressive disease.

Molecular characteristics of low-grade serous carcinoma in effusions.

OBJECTIVE: The molecular characteristics of low-grade serous carcinoma (LGSC) in serous effusions have not been studied previously. The present study analysed the molecular profile of LGSC at this anatomical site. METHODS: Specimens consisted of a series of 17 serous effusions (15 peritoneal, 2 pleural) from 16 patients, of which 15 were LGSC and 2 serous borderline tumour (SBT) who later progressed to LGSC. For comparative purposes, 9 surgical specimens from 6 patients with LGSC were analysed. Fresh-frozen cell pellets and surgical specimens underwent targeted next-generation sequencing covering 50 unique genes. RESULTS: Mutations were found in tumours from 14 of the 22 patients, of whom 4 had 2 different mutations and 10 had a single mutation. Overall, the most common mutations were in KRAS (n = 3) and BRAF (n = 3), followed by NRAS (n = 2), CDK2NA (n = 2), TP53 (n = 2), ATM (n = 2). Mutations in MET, STK11, ERBB2 and FLT3 were found in one case each. Patient-matched specimens had the same molecular profile. Both effusions with TP53 mutation had concomitant ATM mutation, and both stained immunohistochemically with a wild-type pattern. The absence of mutations was associated with a trend for shorter overall survival in univariate analysis (p = 0.072). CONCLUSIONS: The molecular alterations in LGSCs in serous effusions are consistent with those found in solid tumours, with frequent alterations in the mitogen-activated protein kinase pathway. Mutations in LGSC may be a marker of better outcomes.

Comparison of Five Near-Infrared Fluorescent Folate Conjugates in an Ovarian Cancer Model.

PURPOSE: Fluorescence imaging (FLI) using targeted near-infrared (NIR) conjugates aids the detection of tumour lesions pre- and intraoperatively. The optimisation of tumour visualisation and contrast is essential and can be achieved through high tumour-specificity and low background signal. However, the choice of fluorophore is recognised to alter biodistribution and clearance of conjugates and is therefore a determining factor in the specificity of target binding. Although ZW800-1, IRDye® 800CW and ICG are the most commonly employed NIR fluorophores in clinical settings, the fluorophore with optimal in vivo characteristics has yet to be determined. Therefore, we aimed to characterise the impact the choice of fluorophore has on the biodistribution, specificity and contrast, by comparing five different NIR fluorophores conjugated to folate, in an ovarian cancer model. PROCEDURES: ZW800-1, ZW800-1 Forte, IRDye® 800CW, ICG-OSu and an in-house synthesised Cy7 derivative were conjugated to folate through an ethylenediamine linker resulting in conjugates 1-5, respectively. The optical properties of all conjugates were determined by spectroscopy, the specificity was assessed in vitro by flow cytometry and FLI, and the biodistribution was studied in vivo and ex vivo in a subcutaneous Skov-3 ovarian cancer model. RESULTS: We demonstrated time- and receptor-dependent binding of folate conjugates in vitro and in vivo. Healthy tissue clearance characteristics and tumour-specific signal varied between conjugates 1-5. ZW800-1 Forte (2) revealed the highest contrast in folate receptor alpha (FRα)-positive xenografts and showed statistically significant target specificity. While conjugates 1, 2 and 3 are renally cleared, hepatobiliary excretion and no or very low accumulation in tumours was observed for 4 and 5. CONCLUSIONS: The choice of fluorophore has a significant impact on the biodistribution and tumour contrast. ZW800-1 Forte (2) exhibited the best properties of those tested, with significant specific fluorescence signal.

Integrating digital pathology with transcriptomic and epigenomic tools for predicting metastatic uterine tumor aggressiveness.

The incidence of new cancer cases is expected to increase significantly in the future, posing a worldwide problem. In this regard, precision oncology and its diagnostic tools are essential for developing personalized cancer treatments. Digital pathology (DP) is a particularly key strategy to study the interactions of tumor cells and the tumor microenvironment (TME), which play a crucial role in tumor initiation, progression and metastasis. The purpose of this study was to integrate data on the digital patterns of reticulin fiber scaffolding and the immune cell infiltrate, transcriptomic and epigenetic profiles in aggressive uterine adenocarcinoma (uADC), uterine leiomyosarcoma (uLMS) and their respective lung metastases, with the aim of obtaining key TME biomarkers that can help improve metastatic prediction and shed light on potential therapeutic targets. Automatized algorithms were used to analyze reticulin fiber architecture and immune infiltration in colocalized regions of interest (ROIs) of 133 invasive tumor front (ITF), 89 tumor niches and 70 target tissues in a total of six paired samples of uADC and nine of uLMS. Microdissected tissue from the ITF was employed for transcriptomic and epigenetic studies in primary and metastatic tumors. Reticulin fiber scaffolding was characterized by a large and loose reticular fiber network in uADC, while dense bundles were found in uLMS. Notably, more similarities between reticulin fibers were observed in paired uLMS then paired uADCs. Transcriptomic and multiplex immunofluorescence-based immune profiling showed a higher abundance of T and B cells in primary tumor and in metastatic uADC than uLMS. Moreover, the epigenetic signature of paired samples in uADCs showed more differences than paired samples in uLMS. Some epigenetic variation was also found between the ITF of metastatic uADC and uLMS. Altogether, our data suggest a correlation between morphological and molecular changes at the ITF and the degree of aggressiveness. The use of DP tools for characterizing reticulin scaffolding and immune cell infiltration at the ITF in paired samples together with information provided by omics analyses in a large cohort will hopefully help validate novel biomarkers of tumor aggressiveness, develop new drugs and improve patient quality of life in a much more efficient way.

Exosome Secretion and Epithelial-Mesenchymal Transition in Ovarian Cancer Are Regulated by Phospholipase D.

Phospholipase D (PLD) isoenzymes participate in a variety of cellular functions that are mostly attributed to phosphatidic acid (PA) synthesis. Dysregulation of PLD regulates tumor progression and metastasis, yet little is known about the underlying mechanism. We previously reported on the expression and clinical role of the PLD isoenzymes PLD1 and PLD2 in tubo-ovarian high-grade serous carcinoma (HGSC). In the present study, we investigated the biological function of PLD1 and PLD2 using the OVCAR-3 and OVCAR-8 HGSC cell lines. KO cell lines for both PLDs were generated using CRISPR/CAS9 technology and assayed for exosome secretion, spheroid formation, migration, invasion and expression of molecules involved in epithelial-mesenchymal transition (EMT) and intracellular signaling. Significant differences between PLD1 and PLD2 KO cells and controls were observed for all the above parameters, supporting an important role for PLD in regulating migration, invasion, metastasis and EMT.

Data Set for the Reporting of Ovarian, Fallopian Tube and Primary Peritoneal Carcinoma: Recommendations From the International Collaboration on Cancer Reporting (ICCR).

The move toward consistent and comprehensive surgical pathology reports for cancer resection specimens has been a key development in supporting evidence-based patient management and consistent cancer staging. The International Collaboration on Cancer Reporting (ICCR) previously developed a data set for reporting of the ovarian, fallopian tube and primary peritoneal carcinomas which was published in 2015. In this paper, we provide an update on this data set, as a second edition, that reflects changes in the 2020 World Health Organization (WHO) Classification of Female Genital Tumours as well as some other minor modifications. The data set has been developed by a panel of internationally recognized expert pathologists and a clinician and consists of "core" and "noncore" elements to be included in surgical pathology reports, with detailed commentary to guide users, including references. This data set replaces the widely used first edition, and will facilitate consistent and accurate case reporting, data collection for quality assurance and research, and allow for comparison of epidemiological and pathologic parameters between different populations.

Fusion of the HMGA2 and BNC2 Genes in Uterine Leiomyoma With t(9;12)(p22;q14).

BACKGROUND/AIM: The translocation t(9;12) (p22;q14~15) has been reported in lipomas, pleomorphic adenomas, a myolipoma, two chondroid hamartomas, and two uterine leiomyomas. In lipomas and pleomorphic adenomas, the translocation fuses HMGA2 (12q14) with the NFIB gene from 9p22; in myolipoma, it fuses HMGA2 with C9orf92 from 9p22; and in chondroid hamartomas, fluorescence in situ hybridization (FISH) investigations showed the chromosomal aberration to cause intragenic rearrangement of HMGA2. The translocation's molecular consequence in a uterine leiomyoma is described here. MATERIALS AND METHODS: A typical leiomyoma was investigated using banding cytogenetics, FISH, RNA sequencing, reverse transcription polymerase chain reaction and Sanger sequencing. RESULTS: A single translocation, t(9;12)(p22;q14) leading to an HMGA2::BNC2 chimera, was found in tumor cells. A sequence of the untranslated part of exon 5 of HMGA2 (nucleotide 1035 in the NCBI reference sequence NM_003483.4) had fused with a sequence from the untranslated part of exon 7 of BNC2 from 9p22 (nucleotide 9284 in reference sequence NM_017637.6). CONCLUSION: At the molecular level, the t(9;12)(p22;q14~15) found in several benign tumors appears to be heterogeneous fusing HMGA2 with either BNC2, C9orf92 or NFIB which all three map close to one another within a 3 Mbp region in 9p22. Because the fusion point in HMGA2 in the present tumor lays downstream from the first Let-7 miRNA consensus binding site, we conclude that deletion of the first Let-7 miRNA binding site is not important for the transcriptional upregulation of HMGA2 caused by the genomic rearrangement.

A Novel Cryptic t(2;3)(p21;q25) Translocation Fuses the WWTR1 and PRKCE Genes in Uterine Leiomyoma With 3q- as the Sole Visible Chromosome Abnormality.

BACKGROUND/AIM: Deletions in the q arm of chromosome 3 have been reported in uterine leiomyomas, also as sole anomalies. Because some neoplasia-associated deletions may give rise to tumorigenic fusion genes, we chose to investigate thoroughly one such tumor. MATERIALS AND METHODS: A uterine leiomyoma obtained from a 45-year-old woman had the karyotype 46,XX,del(3)(q?)[11]. The tumor was further studied using array comparative genomic hybridization, RNA sequencing, reverse transcription polymerase chain reaction, Sanger sequencing, and fluorescence in situ hybridization methodologies. RESULTS: The deletion was shown to be from 3q22.2 to 3q26.32. Unexpectedly, a cryptic balanced t(2;3)(p21;q25) translocation was also found affecting two otherwise normal chromosomes 2 and 3, i.e., the der(3)t(2;3) was not the deleted chromosome 3. The translocation generated two chimeras between the genes WW domain containing transcription regulator 1 (WWTR1) from 3q25.1 and protein kinase C epsilon (PRKCE) from 2p21. The WWTR1::PRKCE fusion would code for a chimeric serine/threonine kinase, whereas the reciprocal PRKCE::WWTR1 fusion would code for a chimeric transcriptional coactivator protein. CONCLUSION: Leiomyomas carrying a deletion on 3q may also have a balanced t(2;3)(p21;q25) leading to fusion of WWTR1 with PRKCE.

Serine metabolism remodeling after platinum-based chemotherapy identifies vulnerabilities in a subgroup of resistant ovarian cancers.

Resistance to platinum-based chemotherapy represents a major clinical challenge for many tumors, including epithelial ovarian cancer. Patients often experience several response-relapse events, until tumors become resistant and life expectancy drops to 12-15 months. Despite improved knowledge of the molecular determinants of platinum resistance, the lack of clinical applicability limits exploitation of many potential targets, leaving patients with limited options. Serine biosynthesis has been linked to cancer growth and poor prognosis in various cancer types, however its role in platinum-resistant ovarian cancer is not known. Here, we show that a subgroup of resistant tumors decreases phosphoglycerate dehydrogenase (PHGDH) expression at relapse after platinum-based chemotherapy. Mechanistically, we observe that this phenomenon is accompanied by a specific oxidized nicotinamide adenine dinucleotide (NAD+) regenerating phenotype, which helps tumor cells in sustaining Poly (ADP-ribose) polymerase (PARP) activity under platinum treatment. Our findings reveal metabolic vulnerabilities with clinical implications for a subset of platinum resistant ovarian cancers.