Transcriptional regulation of immediate-early gene response by THOC5, a member of mRNA export complex, contributes to the M-CSF-induced macrophage differentiation

Hematopoiesis and commitment to a restricted lineage are guided by a timely expressed set of cytokine receptors and their downstream transcription factors. A member of the mRNA export complex, THOC5 (suppressors of the transcriptional defects of hpr1 delta by overexpression complex 5) is a substrate for several tyrosine kinases such as macrophage colony-stimulating factor (M-CSF) receptor and various leukemogenic tyrosine kinases, such as Bcr-Abl, or NPM-ALK. THOC5 tyrosine phosphorylation is elevated in stem cells from patients with chronic myeloid leukemia, suggesting that THOC5 may be involved in leukemia development. THOC5 is also an essential element in the maintenance of hematopoiesis in adult mice. In this report, we show that THOC5 is located in the nuclear speckles, and that it is translocated from the nucleus to cytoplasm during M-CSF-induced bone marrow-derived macrophage differentiation. Furthermore, we have identified THOC5 target genes by trancriptome analysis, using tamoxifen-inducible THOC5 knockout macrophages. Although only 99 genes were downregulated in THOC5-depleted macrophages, half of the genes are involved in differentiation and/or migration. These include well-known regulators of myeloid differentiation inhibitor of DNA binding (Id)1, Id3, Smad family member 6 (Smad6) and Homeobox (Hox)A1. In addition, a subset of M-CSF-inducible genes, such as Ets family mRNAs are THOC5 target mRNAs. Upon depletion of THOC5, unspliced v-ets erythroblastosis virus E26 oncogene homolog (Ets1) mRNA was accumulated in the nucleus. Furthermore, THOC5 was recruited to chromatin where Ets1 was transcribed and bound to unspliced and spliced Ets1 transcripts, indicating that THOC5 has a role in processing/export of M-CSF-inducible genes. In conclusion, regulation of immediate-early gene response by THOC5, a member of mRNA export complex contributes to the M-CSF-induced macrophage differentiation.

Phase 1 study of lenvatinib combined with carboplatin and paclitaxel in patients with non-small-cell lung cancer

BACKGROUND

This dose-finding study evaluated lenvatinib, an oral multitargeted receptor tyrosine kinase inhibitor, in combination with carboplatin/paclitaxel in chemotherapy-naïve non-small-cell lung cancer (NSCLC) patients.

PATIENTS AND METHODS

Patients received lenvatinib twice daily (BID) with carboplatin (area under the curve 6 mg ml(-1) min(-1), day 1)/paclitaxel (200 mg m(-2), day 1) every 3 weeks. The initial dose of lenvatinib was 6 mg BID. The primary end point was maximum tolerated dose (MTD) of lenvatinib. At the MTD, the cohort was expanded by 16 patients. Safety, pharmacokinetics, pharmacodynamics, and antitumor effects were evaluated.

RESULTS

Twenty-eight patients were treated. At 6 mg BID, dose-limiting toxicities (DLTs) included febrile neutropenia/gingival infection (n=2). No DLTs occurred with 4 mg BID, the recommended MTD for the expansion. Common grade 3/4 toxicities included neutropenia, leukopenia, hypertension, and thrombocytopenia. The combination had no significant impact on individual drug pharmacokinetics. Response rate and median progression-free survival were 68% and 9.0 months, respectively, with 4 mg BID. In the plasma biomarker analysis, stromal cell-derived factor 1α, stem cell factor, and granulocyte colony-stimulating factor correlated with antitumor activity.

CONCLUSION

The MTD for lenvatinib with carboplatin/paclitaxel is 4 mg BID in advanced NSCLC patients. This regimen demonstrated manageable tolerability and encouraging antitumor activity.

Activin A is stimulated by tumor necrosis factor-alpha and modulates collagen gene expression in human amniotic cells

BACKGROUND

Accumulating evidence supports the idea of activin A as a modulator of inflammation. In human pregnancy, elevated activin A concentrations in amniotic fluid are reported in women with intra-amniotic infection and inflammation- induced pre-term birth.

AIM

To test the hypothesis that activin A was involved in the pathophysiology of amnionitis, we evaluated the effects of tumor necrosis factor-α and lipopolysaccharide on activin A production in human amniotic epithelial cells, and the effects of activin A on the expression of collagen mRNA in amniotic mesenchymal cells.

MATERIALS AND METHODS

Amniotic membranes were obtained from patients without systemic disease, signs of premature delivery or fetal complications, during elective cesarean sections at term. Amniotic epithelial cells and mesenchymal cells were separately obtained by enzymatic digestion and cultured. Activin A was measured by enzyme-linked immunosorbent assay and collagen mRNA levels were assessed by quantitative PCR.

RESULTS

Amniotic epithelial cells produced activin A in a cell density- and time-dependent manner. Tumor necrosis factor- α enhanced activin A production in a time-dependent (48-120 h) and dose-dependent (10-300 ng/ml) manner in amniotic epithelial cells. Lipopolysaccharide also stimulated activin A production, but the effect was less prominent. In amniotic mesenchymal cells, the effect of activin A on the expression of type I and type III collagen mRNA was suppressive.

CONCLUSIONS

Tumor necrosis factor-α and lipopolysaccharide stimulated activin A production in amniotic epithelial cells, and activin A modulated expression of collagen mRNA in amniotic mesenchymal cells. These results support the idea that activin A is involved in the pathophysiology of amnionitis.

Gene silencing in Escherichia coli using antisense RNAs expressed from doxycycline-inducible vectors

Here, we report on the construction of doxycycline (tetracycline analogue)-inducible vectors that express antisense RNAs in Escherichia coli. Using these vectors, the expression of genes of interest can be silenced conditionally. The expression of antisense RNAs from the vectors was more tightly regulated than the previously constructed isopropyl-β-D-galactopyranoside-inducible vectors. Furthermore, expression levels of antisense RNAs were enhanced by combining the doxycycline-inducible promoter with the T7 promoter-T7 RNA polymerase system; the T7 RNA polymerase gene, under control of the doxycycline-inducible promoter, was integrated into the lacZ locus of the genome without leaving any antibiotic marker. These vectors are useful for investigating gene functions or altering cell phenotypes for biotechnological and industrial applications.

SIGNIFICANCE AND IMPACT OF THE STUDY

A gene silencing method using antisense RNAs in Escherichia coli is described, which facilitates the investigation of bacterial gene function. In particular, the method is suitable for comprehensive analyses or phenotypic analyses of genes essential for growth. Here, we describe expansion of vector variations for expressing antisense RNAs, allowing choice of a vector appropriate for the target genes or experimental purpose.

A comparison between intraductal papillary neoplasms of the biliary tract (BT-IPMNs) and intraductal papillary mucinous neoplasms of the pancreas (P-IPMNs) reveals distinct clinical manifestations and outcomes

BACKGROUND

Intraductal papillary mucinous neoplasm of the biliary tract (BT-IPMN) has been increasingly recognized as a biliary counterpart of intraductal papillary mucinous neoplasm of the pancreas (P-IPMN). However, there is limited information regarding whether BT-IPMNs and P-IPMNs behave in a similar fashion.

METHODS

We retrospectively compared clinicopathological variables between 9 patients with BT-IPMN and 44 patients with P-IPMN.

RESULTS

There was no significant difference in age between patients with BT-IPMN and those with P-IPMN. The male/female ratio was significantly higher in patients with P-IPMN than in those with BT-IPMN (P = 0.012). Clinical presentation with jaundice was more common in patients with BT-IPMN (67%) than in those with P-IPMN (4.5%, P = 0.002). In addition, serum levels of CEA and CA19-9 were higher in patients with BT-IPMN than in those with P-IPMN (P = 0.019 and P = 0.002, respectively). The pathological diagnosis of malignancy was significantly more common in patients with BT-IPMN (89%) than in those with P-IPMN (23%, P = 0.002). The association with invasive carcinoma was significantly more frequent in patients with BT-IPMN (44.4%) than in those with P-IPMN (6.8%, P = 0.008). Furthermore, survival time after surgical resection was significantly shorter in patients with BT-IPMN than in those with P-IPMN (P = 0.002).

CONCLUSION

These findings reveal differences in clinicopathological features and prognosis between BT-IPMN and P-IPMN, thereby suggesting distinct biological pathways underlying the pathogenesis of these neoplasms.

Induction chemotherapy followed by gefitinib and concurrent thoracic radiotherapy for unresectable locally advanced adenocarcinoma of the lung: a multicenter feasibility study (JCOG 0402)

BACKGROUND

We conducted a feasibility study of induction chemotherapy followed by gefitinib and thoracic radiotherapy (TRT) for unresectable locally advanced adenocarcinoma of the lung.

PATIENTS AND METHODS

Patients received induction chemotherapy with cisplatin (80 mg/m(2), days 1 and 22) and vinorelbine (25 mg/m(2), days 1, 8, 22, and 29) followed by gefitinib (250 mg daily, beginning on day 43, for 1 year) and TRT (60 Gy/30 fractions, days 57-98). The primary end point was feasibility, which was defined as the proportion of patients who completed 60 Gy of TRT and received >75% of the planned dose of gefitinib without developing grade 2 or worse pneumonitis.

RESULTS

Of the 38 enrolled patients, 23 patients [60.5% ; 80% confidence interval (CI) 48.8-71.3] completed treatment without experiencing grade 2 or worse pneumonitis. During the chemoradiation phase, grade 3-4 alanine aminotransferase elevations were observed in 37.1% of the patients. The overall response rate was 73.0% . The median survival time was 28.5 months (95% CI 22.5-38.2), and the 2-year survival rate was 65.4% .

CONCLUSIONS

Although the results did not meet our criterion for feasibility, the toxicity was acceptable. This treatment warrants further evaluation among patients with locally advanced non-small-cell lung cancer harboring epidermal growth factor receptor mutations.

Comparison of chemotherapeutic treatment outcomes of advanced extrapulmonary neuroendocrine carcinomas and advanced small-cell lung carcinoma

BACKGROUND

The chemotherapy for small-cell lung carcinoma (SCLC) has been adopted for advanced extrapulmonary neuroendocrine carcinomas (EP-NECs). The aim of this study was to clarify the efficacy of standard SCLC regimens when used to treat EP-NECs and to compare the outcome with that for SCLC.

METHODS

We reviewed the medical records of 136 patients (41 with EP-NEC and 95 with SCLC) who were treated using a platinum-containing regimen for advanced disease between January 2000 and October 2008 at our hospital.

RESULTS

The primary site of the EP-NEC was the gastrointestinal tract in 18 patients (GI tract group); the liver, biliary tract or pancreas in 16 patients (HBP group), and other sites in 7 patients ('others' group). The response rate in the SCLC patients was 77.8%, and the response rate in the EP-NEC patients was 30.8% (37.5% in the GI tract group, 12.5% in the HBP group, and 57.1% in the 'others' group). The median survival time for the SCLC patients was 13.6 months, while that for the EP-NEC patients was 9.2 months (14.9 months in the GI tract group, 7.8 months in the HBP group, and 8.9 months in the 'others' group). A multivariate analysis demonstrated that a poor performance status, liver involvement, and the treatment regimen were independent unfavorable prognostic factors.

CONCLUSION

The response rate and prognosis of the patients with advanced EP-NECs were worse than those of the patients with SCLC in this study. The Eastern Cooperative Oncology Group performance status, liver involvement, and treatment regimen had a larger impact on the prognosis than the primary tumor site, as demonstrated by multivariate analysis.

Abstract C26: A phase 1 multiple ascending dose study of cabozantinib (XL184) monotherapy in Japanese patients with advanced solid tumors

Background: Cabozantinib is a potent orally available small molecule inhibitor of multiple receptor tyrosine kinases with growth promoting and angiogenic properties. The primary targets of cabozantinib are MET and VEGFR2. In preclinical models, cabozantinib demonstrated significant tumor growth inhibition in multiple tumor models including human medullary thyroid cancer (MTC), human breast cancer, human lung carcinoma and rat glioblastoma. Anti-tumor activity in patients has been observed across a broad range of tumor types including MTC, prostate, ovarian and breast cancer, non-small cell lung cancer (NSCLC), hepatocellular carcinoma, melanoma and glioblastoma. The primary objectives of this open-label phase 1 study are determination of the maximum tolerated dose (MTD) and recommended phase 2 dose in Japanese patients.

Methods: Patients with advanced solid malignancies are enrolled in successive cohorts to receive escalating doses of cabozantinib in a 3+3 trial design. Patients are treated with continuous 4-week cycles of cabozantinib administered orally (PO) once daily (QD). Dose limiting toxicities (DLTs) are determined using Cycle 1 data. Response is assessed on Day 29 and every 8 weeks thereafter by modified RECIST v1.0 criteria and patients with stable disease (SD) or objective response receive continued therapy. Pharmacokinetic (PK) parameters of cabozantinib and relevant plasma markers including VEGF-A, sVEGFR2 and PlGF are being evaluated.

Results: As of 1 September 2011, 6 patients with advanced malignancies have been enrolled: NSCLC (n=3), colorectal cancer, gastrointestinal stromal tumor (GIST), leiomyosarcoma (n=1 each). Patients were pretreated with a median of 3 prior regimens (range, 2 − 7). Patients have been treated at 2 dose levels of 40mg and 60mg free base equivalents (salt strengths of 50mg and 75mg, respectively) PO QD. There have been no DLTs or serious adverse events reported to date. The MTD has not yet been defined. Observed adverse events were generally mild to moderate and include hypertension, palmer-plantar erythrodysesthesia, diarrhea, mucositis, rash, edema and headache. Laboratory abnormalities include elevated AST/ALT, neutropenia, thrombocytopenia and increases in alkaline phosphatase, LDH, lipase and TSH. Results of preliminary PK analysis at the 40mg QD dose level showed that cabozantinib appeared to reach steady-state plasma concentrations by Day 15 and there was evidence of 6- to 7-fold accumulation on Day 19. One patient with NSCLC has had a confirmed partial response with 38% reduction in the sum of target lesions. Three pretreated patients including 2 with NSCLC and 1 with GIST have had SD with reductions in the sum of target lesions of 20, 13 and 16% respectively, and continue treatment with cabozantinib.

Conclusions: Cabozantinib appears well tolerated at doses tested to date. Early signs of antitumor activity including prolonged stable disease and response have been observed in the initial dosing cohorts. Determination of the MTD is ongoing.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C26.