Chromatin-associated CSF-1R binds to the promoter of proliferation-related genes in breast cancer cells.

The colony-stimulating factor-1 (CSF-1) and its receptor CSF-1R physiologically regulate the monocyte/macrophage system, trophoblast implantation and breast development. An abnormal CSF-1R expression has been documented in several human epithelial tumors, including breast carcinomas. We recently demonstrated that CSF-1/CSF-1R signaling drives proliferation of breast cancer cells via 'classical' receptor tyrosine kinase signaling, including activation of the extracellular signal-regulated kinase 1/2. In this paper, we show that CSF-1R can also localize within the nucleus of breast cancer cells, either cell lines or tissue specimens, irrespectively of their intrinsic molecular subtype. We found that the majority of nuclear CSF-1R is located in the chromatin-bound subcellular compartment. Chromatin immunoprecipitation revealed that CSF-1R, once in the nucleus, binds to the promoters of the proliferation-related genes CCND1, c-JUN and c-MYC. CSF-1R also binds the promoter of its ligand CSF-1 and positively regulates CSF-1 expression. The existence of such a receptor/ligand regulatory loop is a novel aspect of CSF-1R signaling. Moreover, our results provided the first evidence of a novel localization site of CSF-1R in breast cancer cells, suggesting that CSF-1R could act as a transcriptional regulator on proliferation-related genes.

AML1/ETO sensitizes via TRAIL acute myeloid leukemia cells to the pro-apoptotic effects of hypoxia.

We determined the effects of severe hypoxia (∼0.1% O2) on acute myeloid leukemia cells expressing the AML1/ETO oncogene. Incubation of Kasumi-1 cells in hypoxia induced growth arrest, apoptosis and reduction of AML1/ETO protein expression. The conditional expression of AML1/ETO in U937-A/E cells showed that hypoxia induces marked apoptosis in AML1/ETO-expressing cells only, pointing to AML1/ETO as a factor predisposing cells to hypoxia-induced apoptosis. In AML1/ETO-expressing cells, hypoxia enhanced TRAIL expression and its proapoptotic effects. AML1/ETO was found to bind TRAIL promoter and induce TRAIL transcription, although TRAIL expression was restrained by a concomitant relative transcription block. In hypoxia, such a TRAIL repression was removed and an increase of TRAIL expression was induced. Finally, blocking anti-TRAIL antibodies markedly reduced (Kasumi-1 cells) or completely inhibited (U937-A/E cells) hypoxia-induced apoptosis. Taken together, these results indicated that hypoxia induces apoptosis in AML1/ETO-expressing cells via a TRAIL/caspase 8-dependent autocrine loop and that TRAIL is a key regulator of hypoxia-induced apoptosis in these cells.

Selective anti-leukaemic activity of low-dose histone deacetylase inhibitor ITF2357 on AML1/ETO-positive cells.

We analysed the in vitro effects of a new hydroxamate derivative, ITF2357, on AML cells. ITF2357 potently induced histone acetylation. ITF2357 0.1 microM blocked proliferation and induced apoptosis in AML1/ETO-positive Kasumi-1 cells, while AML1/ETO-negative HL60, THP1 and NB4 cell lines were sensitive only to 1 microM ITF2357. Apoptosis was induced by 0.1 microM ITF2357 in AML1/ETO-positive primary blasts and U937-A/E cells induced to express AML1/ETO, but not in U937-A/E cells non-expressing AML1/ETO. In Kasumi-1 cells 0.1 microM ITF2357 induced AML1/ETO degradation through a caspase-dependent mechanism. ITF2357 0.1 microM also determined DNMT1 efflux from, and p300 influx to, the nucleus. Moreover, 0.1 microM ITF2357 determined local H4 acetylation and release of DNMT1, HDAC1 and AML1/ETO, paralleled by recruitment of p300 to the IL-3 gene promoter. ITF2357 treatment, however, did not induce re-expression of IL-3 gene. Accordingly, the methylation level of IL-3 promoter, as well as of several other genes, was unmodified. In conclusion, ITF2357 emerged as an anti-leukaemic agent very potent on AML cells, and on AML1/ETO-positive cells in particular. More relevantly, clearly emerged from our results that ITF2357 could be an ideal agent to treat AML subtypes presenting AML1/ETO fusion protein which determine HDAC involvement in leukaemogenesis.

Results of rebiopsy for suspected prostate cancer in symptomatic men with elevated PSA levels.

AIM OF THE STUDY: To develop indications for repeat biopsy in patients with suspected prostate cancer and first negative biopsy. MATERIALS AND METHODS: 148 consecutive patients, submitted to two or more biopsies for suspected prostate cancer, were extracted from our database on prostatic diseases. Patients were stratified according to the results of the last biopsy (benign or carcinoma) considering the results of the first and of the last biopsy when more than two biopsies had been performed. PSA velocity was calculated when the interval between PSA obtained before the initial and the final biopsy was at least 6 months; PSA velocities were annualized and absolute changes between the two groups were analyzed. RESULTS: Prostatic carcinoma was detected in 60 of the 148 patients (40.5%), including 19 of 41 (46.4%) with prostatic intraepithelial neoplasia (PIN) and 45 of 107 (42.1%) with normal tissue or prostatic epithelial atrophia on initial biopsy. 20% of patients (4 of 20) with low-grade PIN and 71.1% (15 of 21) with high-grade PIN had cancer at repeat biopsy. The mean PSA value of patients with carcinoma on the repeat biopsy was higher than that of patients without carcinoma (13.3 vs. 10.7 ng/ml). However, this difference was not statistically significant (p = 0.37). Mean PSA velocity increased for patients with a final diagnosis of carcinoma versus those without evidence of carcinoma (+0.3 vs. +1.4 ng/ml/year); this difference was statistically significant (p = 0.002). CONCLUSIONS: According to these results, patients with either PIN II-III, or high PSA and PIN I on initial biopsy, and/or with elevated PSA velocity (more than 1 ng/ml/year) should undergo repeat prostate needle biopsy, being at high risk of prostate carcinoma.

Procollagen type I carboxyterminal extension peptide in serum: a reliable marker of bone metastatic disease in newly diagnosed prostate cancer?

OBJECTIVE: This study evaluates the accuracy of type I procollagen, a bone matrix glycoprotein, and prostate-specific antigen (PSA) as markers for predicting the results of radionuclide bone scan in newly diagnosed, previously untreated patients with prostate cancer. METHODS: 74 patients underwent serum PSA and procollagen determination using specific antibodies. A staging radionuclide bone scan was then performed; patients with positive bone scan were submitted to x-rays of the suspicious zones. Then, we calculated sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy of procollagen and PSA in the detection of bone metastases. RESULTS: Procollagen alone had 83.3% sensitivity, 96% specificity, 90.9% positive predictive value, 92.3% negative predictive value and 91.9% overall accuracy. PSA alone had 70.1% sensitivity, 86% specificity, 70.8% positive predictive value, 86% negative predictive value and 81.1% overall accuracy. CONCLUSIONS: According to our data, we no longer perform a staging radionuclide bone scan in patients with PSA < 20 ng/ml and normal procollagen level, diminishing the number of radionuclide bone scans and increasing the overall net savings for the health care system.

Serum levels of tumor-associated trypsin inhibitor (TATI) in benign and malignant gynecological diseases.

The behavior of tumor-associated trypsin inhibitor (TATI) as a marker for gynecological cancer was studied in a control population and in patients with different benign and malignant diseases. When a cut-off level of 21.4 micrograms/l was used the specificity was 100% in patients with benign diseases. The sensitivity in patients with malignant tumors was low for cervical and corpus cancer, 13% and 14%, respectively, whereas it was 33% in all the ovarian malignant tumors, reaching 60% in the mucinous type. There was a clear correlation between TATI level and stage.

[The renin-angiotensin-aldosterone system in liver cirrhosis]. / Il sistema renina-angiotensina-aldosterone nella cirrosi epatica.

The role of the RAA system in the genesis of ascites in liver cirrhosis patients is not yet perfectly clear. The present study was conducted on 176 cirrhosis patients in order to investigate RAA system function, to assess the changes taking place in the various stages of the disease and to correlate such changes with the various kidney function parameters. The patients were divided into 3 groups as follows: Group I: patients without ascites on admission and with no history of the condition; Group 2: patients with ascites of recent onset and/or response to diuretic treatment; Group 3: patients with ascites not responsive to diuretic treatment. In Group 1, 19 patients (38%) reveal a significant reduction in renin activity together with portal hypertension and increased hydrosaline retention. In Group 2 renin activity was reduced in 4 patients (6%), aldosterone activity in 3 (4%). Progressive deterioration in liver function parameters and progressive activation of the RAA system combined with reduced sodiuria content were found in over 50% of these patients. The presence or absence of portal hypertension in this group was not related to significant changes in diuresis or sodiuria. In Group 3 renin was activated in 54 patients (89%), aldosterone in 58 (95%) and there was also a distinct reduction in sodiuria (96% of patients) and chloruria (100%). A substantial increase was also noted in the incidence of low blood sodium (53%) while portal hypertension was found in 97% of patients. On the basis of those data it may be hypothesised that high pressure inside the liver creates the stimulus for primary sodium retention. The decrease in effective blood volume after vasodilation, accentuated by low blood albumin and splanchnic venous stagnation may the stimulate the sympathetic nervous system and RAA system. Hyperaldosteronism only becomes the dominant factor in renal imbalance when the cirrhosis reaches the resistant ascites phase.