Identification of a Novel MAN1A1-ROS1 Fusion Gene Through mRNA-based Screening for Tyrosine Kinase Gene Aberrations in a Patient with Leiomyosarcoma.

BACKGROUND: Soft tissue sarcomas are a heterogeneous group of rare malignant tumors. Advanced soft tissue sarcomas have a poor prognosis, and effective systemic therapies have not been established. Tyrosine kinases are increasingly being used as therapeutic targets for a variety of cancers and soft tissue sarcomas. Although complex karyotype sarcomas typically tend to carry more potentially actionable genetic alterations than do translocation-associated sarcomas (fusion gene sarcomas), based on our database review, we found that leiomyosarcoma and malignant peripheral nerve sheath tumors have lower frequencies of potential targets than other nontranslocation soft tissue sarcomas. We theorized that both leiomyosarcoma and malignant peripheral nerve sheath tumors might be included in any unique translocations. Furthermore, if tyrosine kinase imbalances, especially fusion genes, occur in patients with leiomyosarcomas and malignant peripheral nerve sheath tumors, tyrosine kinase inhibitors might be a drug development target for this sarcoma. In this study, we used a tyrosine kinase screening system that could detect an imbalance in mRNA between 5'- and 3'-sides in tyrosine kinase genes to identify potential novel therapeutic tyrosine kinase targets for soft tissue sarcomas. QUESTIONS/PURPOSES: (1) Are there novel therapeutic tyrosine kinase targets in tumors from patients with soft tissue sarcomas that are detectable using mRNA screening focusing on imbalance expressions between the 5' and 3' end of the kinase domain? (2) Can potential targets be verified by RNA sequencing and reverse transcription PCR (RT-PCR)? (3) Will potential fusion gene(s) transform cells in in vitro assays? (4) Will tumors in mice that have an identified fusion gene respond to treatment with a therapeutic drug directed at that target? METHODS: We used mRNA screening to look for novel tyrosine kinase targets that might be of therapeutic potential. Using functional assays, we verified whether the identified fusion genes would be good therapeutic candidates for soft tissue sarcomas. Additionally, using in vivo assays, we assessed whether suppressing the fusion's kinase activity has therapeutic potential. Study eligibility was based on a patient having high-grade spindle cell and nontranslocation sarcomas, including leiomyosarcoma, malignant peripheral nerve sheath tumor, and high-grade myxofibrosarcoma. Between 2015 and 2019, of the 172 patients with soft tissue sarcomas treated with surgical resection at Juntendo University Hospital, 72 patients had high-grade nontranslocation sarcomas. The analysis was primarily for leiomyosarcoma and malignant peripheral nerve sheath tumors, and there was a limitation of analysis size (reagent limitations) totaling 24 samples at the start of the study. We collected additional samples from a sample bank at the Tokyo Medical and Dental University to increase the number of sarcomas to study. Therefore, in this study, a total of 15 leiomyosarcoma samples, five malignant peripheral nerve sheath tumors samples, and four high-grade myxofibrosarcoma samples were collected to achieve the sample size of 24 patients. To identify tyrosine kinase fusion genes, we designed a NanoString-based assay (NanoString Technologies Inc, Seattle, WA, USA) to query the expression balances regarding transcripts of 90 tyrosine kinases at two points: the 5' end of the kinase domain and within the kinase domain or 3' end of the kinase domain. The tumor's RNA was hybridized to the NanoString probes and analyzed for the expression ratios of outliers from the 3' to 5' end of the kinase domain. Presumed novel fusion events in these positive tumors that were defined by NanoString-based assays were confirmed tyrosine kinase fusion genes by RNA sequencing and confirmatory RT-PCR. Functional analyses consisting of in vitro and in vivo assays were also performed to elucidate whether the identified tyrosine kinase gene fusions were associated with oncogenic abilities and drug responses. RESULTS: We identified aberrant expression ratios regarding the 3' to 5' end of the kinase domain ratios in ROS1 transcripts in a leiomyosarcoma in a 90-year-old woman. A novel MAN1A1-ROS1 fusion gene was identified from her thigh tumor through RNA sequencing, which was confirmed with real-time PCR. In functional assays, MAN1A1-ROS1 rearrangement revealed strong transforming potential in 3T3 cells. Moreover, in an in vivo assay, crizotinib, a ROS1 inhibitor, markedly inhibited the growth of MAN1A1-ROS1 rearrangement-induced transformed cells in a dose-dependent manner. CONCLUSION: We conducted tyrosine kinase screening to identify new therapeutic targets in soft tissue sarcomas. We found a novel MAN1A1-ROS1 fusion gene that may be a therapeutic target in patients with leiomyosarcoma. This study demonstrates that the mRNA screening system may aid in the development of useful therapeutic options for soft tissue sarcomas. CLINICAL RELEVANCE: If novel tyrosine fusions such as MAN1A1-ROS1 fusion can be found in sarcomas from other patients, they could offer avenues for new molecular target therapies for sarcomas that currently do not have effective chemotherapeutic options. Therefore, the establishment of a screening system that includes both genomic and transcript analyses in the clinical setting is needed to verify our discoveries and take the developmental process of treatment to the next step.

Targeting Hedgehog Pathway and DNA Methyltransferases in Uterine Leiomyosarcoma Cells.

Uterine leiomyosarcoma (LMS) is an aggressive tumor that presents poor prognosis, high rates of recurrence and metastasis. Because of its rarity, there is no information available concerning LMS molecular mechanisms of origin and development. Here, we assessed the expression profile of Hedgehog (HH) signaling pathway markers and the effects of their pharmacological inhibition on uterine smooth muscle (UTSM), leiomyoma and LMS cells. Additionally, we also evaluated the effects of DNMTs inhibition on LMS cells behavior. Cell proliferation, migration and apoptosis rates were evaluated by MTT, Scratch and Annexin V assays, respectively. RNA expression and protein levels were assessed by qRT-PCR and Western blot. We found that SMO and GLIs (1, 2 and 3) expression was upregulated in LMS cells, with increased nuclear levels of GLI proteins. Treatment with LDE225 (SMOi) and Gant61 (GLIi) resulted in a significant reduction in Glis protein levels in LMS (p < 0.05). Additionally, the expression of DNMT (1, 3a, and 3b), as well as GLI1 nuclear expression, was significantly decreased after treatment with HH inhibitor in LMS cells. Our results showed that blocking of SMO, GLI and DNMTs is able to inhibit LMS proliferation, migration and invasion. Importantly, the combination of those treatments exhibited a potentiated effect on LMS malignant features due to HH pathway deactivation.

Clinical significance of cancer specific methylation of the CDO1 gene in small bowel cancer.

Although small bowel cancer (SBC) is extremely rare, its prognosis is poor, and molecular mechanism of the SBC development remains unclear. The aim of our study is to elucidate whether DNA methylation of the promoter region of the cancer-specific methylation gene, cysteine dioxygenase 1 (CDO1), contributes to the carcinogenic process in SBC. The study group comprised patients with 53 patients with SBC, 107 colorectal cancer (CRC), and other rare tumors of the small intestine such as 4 malignant lymphomas, 2 leiomyosarcomas, and 9 gastrointestinal stromal tumors. We analyzed the extent of methylation in each tissue using quantitative TaqMan methylation-specific PCR for CDO1. Significantly higher CDO1 methylation was observed in cancer tissues compared with non-cancerous mucosa of the small intestine (ROC = 0.96). Among the various clinicopathological factors, positive correlation of CDO1 methylation with tumor diameter was observed (R = 0.31, p = 0.03), and the CDO1 methylation level was a possible prognostic factor for relapse-free survival (p = 0.09). Compared with CRC, SBC had a significantly poorer prognosis (p = 0.007) and displayed a significantly higher CDO1 methylation level (p < 0.0001). Intriguingly, especially in pStage I/II, there were robust prognostic difference between SBC and CRC (p = 0.08 / p < 0.0001), which may reflect CDO1 methylation status (p = 0.02 / p = 0.001). Among small bowel tumors, CDO1 methylation in SBC was higher in order of malignant lymphoma, cancer, and leiomyosarcoma/GIST (p = 0.002) by ANOVA. The CDO1 gene shows extremely cancer-specific hypermethylation, and it can be a prognostic marker in SBC.

Discovery and Characterization of Recurrent, Targetable ALK Fusions in Leiomyosarcoma.

Soft-tissue sarcomas such as leiomyosarcoma pose a clinical challenge because systemic treatment options show only modest therapeutic benefit. Discovery and validation of targetable vulnerabilities is essential. To discover putative kinase fusions, we analyzed existing transcriptomic data from leiomyosarcoma clinical samples. Potentially oncogenic ALK rearrangements were confirmed by application of multiple RNA-sequencing fusion detection algorithms and FISH. We functionally validated the oncogenic potential and targetability of discovered kinase fusions through biochemical, cell-based (Ba/F3, NIH3T3, and murine smooth muscle cell) and in vivo tumor modeling approaches. We identified ALK rearrangements in 9 of 377 (2.4%) patients with leiomyosarcoma, including a novel KANK2-ALK fusion and a recurrent ACTG2-ALK fusion. Functional characterization of the novel ALK fusion, KANK2-ALK, demonstrates it is a dominant oncogene in Ba/F3 or NIH3T3 model systems, and has tumorigenic potential when introduced into smooth muscle cells. Oral monotherapy with targeted ALK kinase inhibitor lorlatinib significantly inhibits tumor growth and prolongs survival in a murine model of KANK2-ALK leiomyosarcoma. These results provide the first functional validation of a targetable oncogenic kinase fusion as a driver in a subset of leiomyosarcomas. Overall, these findings suggest that some soft-tissue sarcomas may harbor previously unknown kinase gene translocations, and their discovery may propel new therapeutic strategies in this treatment-refractory cancer. IMPLICATIONS: A subset of leiomyosarcomas harbor previously unrecognized oncogenic ALK fusions that are highly responsive to ALK inhibitors and thus these data emphasize the importance of detailed genomic investigations of leiomyosarcoma tumors.

Dual inhibition of the PI3K/AKT/mTOR pathway suppresses the growth of leiomyosarcomas but leads to ERK activation through mTORC2: biological and clinical implications.

The PI3K/AKT/mTOR pathway plays a crucial role in the development of leiomyosarcomas (LMSs). In this study, we tested the efficacy of dual PI3K/mTOR (BEZ235), PI3K (BKM120) and mTOR (everolimus) inhibitors in three human LMS cell lines. In vitro and in vivo studies using LMS cell lines showed that BEZ235 has a significantly higher anti-tumor effect than either BKM120 or everolimus, resulting in a greater reduction in tumor growth and more pronounced inhibitory effects on mitotic activity and PI3K/AKT/mTOR signaling. Strikingly, BEZ235 but neither BKM120 nor everolimus markedly enhanced the ERK pathway. This effect was reproduced by the combination of BKM120 and everolimus, suggesting the involvement of mTORC2 via a PI3K-independent mechanism. Silencing of RICTOR in LMS cells confirmed the role of mTORC2 in the regulation of ERK activity. Combined treatment with BEZ235 and GSK1120212, a potent MEK inhibitor, resulted in synergistic growth inhibition and apoptosis induction in vitro and in vivo. These findings document for the first time that dual PI3K/mTOR inhibition in leiomyosarcomas suppress a negative feedback loop mediated by mTORC2, leading to enhanced ERK pathway activity. Thus, combining a dual PI3K/mTOR inhibitor with MEK inhibitors may be a relevant approach to increase anti-tumor activity and prevent drug resistance in patients with LMS.

Fumarase-deficient Uterine Leiomyomas: An Immunohistochemical, Molecular Genetic, and Clinicopathologic Study of 86 Cases.

Loss-of-function germline mutations in the fumarase (FH) gene of the Krebs cycle characterize hereditary leiomyomatosis and renal cell cancer syndrome. Fumarase (FH) deficiency can be diagnosed by the loss of immunohistochemical expression. In this study, we investigated the occurrence and clinicopathologic features of FH-deficient uterine smooth muscle tumors (SMTs). A total of 1583 uterine and 157 nonuterine SMTs were examined using a polyclonal FH antibody and automated immunohistochemistry, and 86 uterine leiomyomas with an FH loss were identified. The frequencies of FH deficiency for subcohorts of uterine SMTs were 1.6% for unselected nonatypical leiomyomas, 1.8% for cellular leiomyomas, 37.3% for atypical leiomyomas, and 0% for leiomyosarcomas. One extrauterine, retroperitoneal estrogen receptor-positive leiomyoma was also FH deficient. The patient age of FH-deficient uterine leiomyomas was 20 to 52 years (median, 38 y). Grossly, these tumors were often soft and amorphous resembling a fibrothecoma. Histologically, the FH-deficient nonatypical leiomyomas lacked cellular packeting and distinct collagenous zones and showed chain-like or palisading nuclear arrangements, prominent staghorn-shaped blood vessels, oval nuclei with no or at most mild atypia, small eosinophilic nucleoli, and a low mitotic rate (0 to 1/10 HPF). The FH-deficient atypical leiomyomas had nuclear atypia often manifesting as multinucleation, prominent eosinophilic nucleoli, and mitotic activity up to 7/10 HPF, with atypical mitoses seen in 32% of cases. However, similar histologic changes were seen in some non-FH-deficient atypical leiomyomas. Loss-of-function FH-gene mutations including 5 whole-gene deletions and 3 frameshift mutations were identified in 8 of 16 FH-deficient nonatypical leiomyomas using multiplex ligation-dependent probe amplification and Sanger sequencing, respectively. Follow-up data on patients with FH-deficient atypical uterine leiomyomas revealed 19 patients alive (median follow-up 27 y) and 5 patients dead. Deaths occurred 9 to 30 years after surgery at a median age of 72 years; causes of death could not be determined. These results indicate that FH-deficient uterine leiomyomas occur with a high frequency among atypical leiomyomas and infrequently in nonatypical leiomyomas and are often histologically distinctive. They seem to have a low biological potential and lack any significant association with leiomyosarcoma.

MMPs and angiogenesis affect the metastatic potential of a human vulvar leiomyosarcoma cell line.

Gynaecological leiomyosarcoma (gLMS) represent a heterogeneous group of soft tissue sarcoma, characterized by rare incidence, high aggressiveness and propensity to infiltrate secondary organs, poor prognosis and lethality, because of the lack of biological mechanisms that underlying their progression and effective pharmaceutical treatments. This study was focused on some of the aspects of progression and dissemination of a subtype of gLMS namely vulvar LMS (vLMS). We therefore used a vulvar LMS-derived cell line namely SK-LMS-1, coupled with in vitro and in vivo assays. We observed that SK-LMS-1 cells have a strong invasive capacity in vitro, through the activity of matrix metalloproteinases 2 and 9, while in vivo these cells induce a strong angiogenic response and disseminate to the chick embryo liver. Therefore, we postulate that metalloproteinases are involved in the spreading behaviour of SK-LMS-1. Further investigations are necessary to better understand the molecular and cellular machinery involved in the progression of this malignancy.

[Extracting and study of biochemical properties of thiamine pyrophosphokinase from non-malignant and tumor tissue of myometrium].

The method of extraction and purification of thiamine pyrophosphokinase from non-malignant and tumor tissue of myometrium has been elaborated. Kinetic characteristics of T-kinase from non-malignant and tumor tissue of women myometrium have been studied. It has been shown, that malignization of myometrium is accompanied by a decrease in affinity of thiamine pyrophosphokinase from tumor to thiamine and by an increase in sensitivity of the enzyme from tumor to thiochrome.

EGFR inhibition abrogates leiomyosarcoma cell chemoresistance through inactivation of survival pathways and impairment of CSC potential.

BACKGROUND: Tumor cells with stem-like phenotype and properties, known as cancer stem cells (CSC), have been identified in most solid tumors and are presumed to be responsible for driving tumor initiation, chemoresistance, relapse, or metastasis. A subpopulation of cells with increased stem-like potential has also been identified within sarcomas. These cells are endowed with increased tumorigenic potential, chemoresistance, expression of embryonic markers, and side population(SP) phenotype. Leiomyosarcomas (LMS) are soft tissue sarcomas presumably arising from undifferentiated cells of mesenchymal origin, the Mesenchymal Stem Cells (MSC). Frequent recurrence of LMS and chemoresistance of relapsed patients may likely result from the failure to target CSC. Therefore, therapeutic cues coming from the cancer stem cell (CSC) field may drastically improve patient outcome. METHODOLOGY/PRINCIPAL FINDINGS: We expanded LMS stem-like cells from patient samples in vitro and examined the possibility to counteract LMS malignancy through a stem-like cell effective approach. LMS stem-like cells were in vitro expanded both as "tumor spheres" and as "monolayers" in Mesenchymal Stem Cell (MSC) conditions. LMS stem-like cells displayed MSC phenotype, higher SP fraction, and increased drug-extrusion, extended proliferation potential, self-renewal, and multiple differentiation ability. They were chemoresistant, highly tumorigenic, and faithfully reproduced the patient tumor in mice. Such cells displayed activation of EGFR/AKT/MAPK pathways, suggesting a possibility in overcoming their chemoresistance through EGFR blockade. IRESSA plus Vincristine treatment determined pathway inactivation, impairment of SP phenotype, high cytotoxicity in vitro and strong antitumor activity in stem-like cell-generated patient-like xenografts, targeting both stem-like and differentiated cells. CONCLUSIONS/SIGNIFICANCE: EGFR blockade combined with vincristine determines stem-like cell effective antitumor activity in vitro and in vivo against LMS, thus providing a potential therapy for LMS patients.

ROR2 is a novel prognostic biomarker and a potential therapeutic target in leiomyosarcoma and gastrointestinal stromal tumour.

Soft-tissue sarcomas are a group of malignant tumours whose clinical management is complicated by morphological heterogeneity, inadequate molecular markers and limited therapeutic options. Receptor tyrosine kinases (RTKs) have been shown to play important roles in cancer, both as therapeutic targets and as prognostic biomarkers. An initial screen of gene expression data for 48 RTKs in 148 sarcomas showed that ROR2 was expressed in a subset of leiomyosarcoma (LMS), gastrointestinal stromal tumour (GIST) and desmoid-type fibromatosis (DTF). This was further confirmed by immunohistochemistry (IHC) on 573 tissue samples from 59 sarcoma tumour types. Here we provide evidence that ROR2 expression plays a role in the invasive abilities of LMS and GIST cells in vitro. We also show that knockdown of ROR2 significantly reduces tumour mass in vivo using a xenotransplantation model of LMS. Lastly, we show that ROR2 expression, as measured by IHC, predicts poor clinical outcome in patients with LMS and GIST, although it was not independent of other clinico-pathological features in a multivariate analysis, and that ROR2 expression is maintained between primary tumours and their metastases. Together, these results show that ROR2 is a useful prognostic indicator in the clinical management of these soft-tissue sarcomas and may represent a novel therapeutic target.

Prognostic significance of Dicer cellular levels in soft tissue sarcomas.

In the present study we assessed the expression and distribution of endoribonuclease Dicer in soft tissue tumors and correlated its cellular levels with clinicopathological parameters, including clinical outcome. Dicer was expressed in the tested cell line as well as in the majority of the sarcomas examined. Staining intensity was significantly higher in sarcomas compared with benign neoplasms and in high-grade compared with low-grade tumors. Elevated Dicer immunoreactivity was strongly associated with poor outcome and Dicer cellular levels were an independent negative prognostic factor.

Trabectedin-related rhabdomyolysis: an uncommon but fatal toxicity.

Rhabdomyolysis is defined as the dissolution of striped muscle characterized by the leakage of intracellular muscle components into the circulation, which can ultimately lead to renal failure with a possible fatal outcome. Trabectedin is a potential cause of rhabdomyolysis. Herein, we describe a case of rhabdomyolysis in a female patient with recurrent metastatic leiomyosarcoma of the uterus and who had full recovery, and we review the already published cases in order to identify a common pattern of emergence.

Curcumin disrupts uterine leiomyosarcoma cells through AKT-mTOR pathway inhibition.

OBJECTIVE: Uterine leiomyosarcoma generally has an unfavorable response to standard chemotherapy. The loss of PTEN which results in constitutive AKT-mTOR activation causes an increase in leiomyosarcoma formation in mice. The active ingredient derived from the herb Curcuma longa, curcumin, shows antitumor properties in a variety of cancer cell lines by altering a number of oncogenic pathways. To explore the possibility of curcumin as an alternative to standard chemotherapy, we decided to investigate curcumin's antitumor effect on uterine leiomyosarcoma cells. METHODS: Human leiomyosarcoma cell lines, SKN and SK-UT-1, were cultured for in vitro experiments. Rapamycin or curcumin was added in different doses and their effect on cell growth was detected by MTS assay. The influence of rapamycin or curcumin on AKT, mTOR, p70S6 and S6 phosphorylation and protein expression was detected by Western Blotting. The ability of rapamycin or curcumin to induce apoptosis was determined by Western blotting using cleaved-PARP specific antibody, Caspase-3 activity assay and TUNEL assay. RESULTS: Both rapamycin and curcumin significantly reduced SKN cell proliferation. Curcumin inhibited mTOR, p70S6 and S6 phosphorylation similar with rapamycin. Cleaved PARP, caspase-3 activity and DNA fragmentation increased proportional with curcumin concentration. At a high concentration, curcumin significantly induced apoptosis in SKN cells, but not rapamycin. CONCLUSIONS: Curcumin inhibited uterine leiomyosarcoma cells' growth by targeting the AKT-mTOR pathway for inhibition. However, rapamycin, a specific mTOR inhibitor, did not induce apoptosis in SKN cells unlike curcumin that also has a pro-apoptotic potential in SKN cells.

[Topoisomerase IIalpha activity and tumor cell proliferation level from the degree of bromodeoxyuridine label in uterine body leiomyosarcoma].

The investigation was undertaken to estimate the expression of the enzyme gyrase Topoisomerase IIalpha (TOPOIIalpha) and proliferative activity from the level of bromodeoxyuridine (Brdu) in uterine body leiomyosarcoma (UBL) (n=66) versus the unchanged myometrium (UM), a tumor of uncertain malignancy potential (STUMP) (n=12), and leiomyoma (LM) (n=46). An immunohistochemical technique was used to reveal TopOIIalpha and Brdu. The findings indicated that Brdu was undetectable in UM and simple LM and that TOPOIIalpha activity was low. At the same time there was an exponential rise in the activity of the enzyme and cells during the S phase of the cell cycle from cellular LM to UBL. An increase was also noted in the study markers as sarcoma malignancy progressed. Thus, it can be said that the estimation of the number of cell S fractions and the activity of TOPOIIalpha in UM, LM, STUMP, and UBL may serve as a relatively simple and reliable method for the differential diagnosis of benign and malignant smooth muscle tumors of the uterine body and the determination of the activity of the enzyme may be used to define the degree of tumor chemoresistance in the complex treatment of patients with UBL.

Inhibition of lipoxygenase (LOX) and anticancer activity caused by gold(I) mixed ligands complexes of triphenylphosphine and thioamides.

Four mixed ligand gold(I) complexes with the thioamides 2-mercapto-thiazolidine (mtzdH), 2-mercapto-benzothiazole (mbztH) and 5-chloro-2-mercapto-benzothiazole (ClmbztH) and triphenylphosphine (tpp) of formulae [Au(tpp)Cl] (1) [Au(tpp)(mtzd)] (2), [Au(tpp)(mbzt)] (3) and [Au(tpp)(Clmbzt)] (4), already known, were used to study their mechanism of inhibition activity towards the catalytic oxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX), kinetically and theoretically. The results are compared to those of cisplatin. In addition, the anticancer cell screening results against leimyosarcoma (LMS) cells have shown that 2-4 complexes were more active than cisplatin. The uptake of complexes in LMS cells were also studied with electrospray ionisation mass spectrometry spectroscopy.

Death-associated protein kinase is essential for the survival of various types of uterine cancer cells.

We recently showed that targeted knockdown of death-associated protein kinase (DAPK) expression induces apoptosis in the human endometrial adenocarcinoma cell line HHUA. To investigate the possibility that DAPK may represent a molecular target for anticancer therapies for advanced uterine cancers, we examined the effects of DAPK siRNA transfections on the viability of five different human uterine cancer cell lines. The five uterine cell lines comprised three differentiated endometrial adenocarcinomas, one leiomyosarcoma and one carcinosarcoma. Cell death assays showed that the DAPK siRNA transfection significantly increased the cell death in all five uterine cancer cells examined. Ribonuclease protection assays did not show any remarkable changes in the bcl-2 family gene expressions after the DAPK siRNA transfection in HHUA cells. Since DAPK-mutant mice were reported to be fertile and do not show lethality, DAPK may play a central role in the immortalization and carcinogenesis of uterine cancer cells, possibly without bcl-2 family-related apoptotic regulation. These results indicate that DAPK can be a convincing candidate for molecularly targeted anticancer therapies for patients with various types of advanced uterine cancers, including carcinosarcoma and leiomyosarcoma.

Hepatocyte growth factor activator inhibitors (HAI-1 and HAI-2) are potential targets in uterine leiomyosarcoma.

Hepatocyte growth factor activator inhibitors (HAI-1 and HAI-2) are Kunitz-type serine protease inhibitors that have a broad inhibitory spectrum against serine proteases. This study examined the role of HAI-1 and HAI-2 in uterine leiomyosarcoma (LMS) patients, and in vitro. HAI-1 and HAI-2 was examined in uterine normal smooth muscle, leiomyoma and LMS specimens using immunohistochemistry. We investigated biological functions and inhibitory effects of HAI-1 and HAI-2 using uterine LMS cell line SK-LMS-1 and SKN. The expression levels of HAI-1 and HAI-2 were significantly decreased in uterine LMS specimens relative to corresponding uterine normal smooth muscle and leiomyoma specimens. Furthermore, the low HAI-1 and HAI-2 expression was a significant predictor for poor prognosis when compared with high HAI-1 and HAI-2 expression (disease-free survival rate; p=0.024 and p=0.045, overall survival rate; p=0.043 and p=0.009). HAI-1 and HAI-2 showed potential inhibitory effects that mediated cell proliferation, migration and cellular invasion which led to apoptosis and necrosis through a reduction of HGFA, matriptase and hepsin expression. These findings indicate that HAI-1 and HAI-2 may be possible tumor suppressor genes for uterine LMS and thus, both could be considered therapeutic agents for the treatment of LMS.

Treatment of advanced uterine leiomyosarcoma with aromatase inhibitors.

BACKGROUND: Aromatase inhibitors are sometimes used in the treatment of selected patients with uterine leiomyosarcoma (LMS), but there are few data assessing the efficacy of aromatase inhibitors in this setting. METHODS: We performed a retrospective electronic medical record review of patients with uterine LMS treated with an aromatase inhibitor at Memorial Sloan-Kettering Cancer Center between 1998 and 2008. We assessed progression-free survival (PFS) and objective response among patients with measurable disease and explored the correlation of hormone receptor status with outcome. RESULTS: Forty patients with advanced or recurrent uterine LMS were treated with aromatase inhibitors. Thirty-four patients had measurable disease. Hormone receptor status for these patients was as follows: estrogen receptor (ER) positive-22, ER negative-9, ER unknown-3, progesterone receptor (PR) positive-10, PR negative-10, PR unknown-14. Aromatase inhibitors used were letrozole (in 74% of patients), anastrozole (21%), and exemestane (6%). Median PFS was 2.9 months (95% CI: 1.8-5.1). The 1-year PFS rate was 28% (95% CI: 11-48%) for ER and/or PR positive uterine LMS. Best objective response was partial response (PR) in 3/34 patients (9%) (all of whom were ER positive). CONCLUSIONS: In this population of patients with mostly low-volume and ER positive uterine LMS, aromatase inhibitors achieved objective response in only 9%. Relatively prolonged PFS was observed among ER positive uterine LMS patients. In the absence of a no-treatment control group, the prolonged PFS cannot be attributed solely to the activity of the aromatase inhibitor treatment since it may reflect the underlying biology of low-volume, ER positive uterine LMS.