Marina Gardiman

MicroRNA expression profiling of human metastatic cancers identifies cancer gene targets

Small non‐coding microRNAs (miRNAs) contribute to cancer development and progression, and are differentially expressed in normal tissues and cancers. However, the specific role of miRNAs in the metastatic process is still unknown. To seek a specific miRNA expression signature characterizing the metastatic phenotype of solid tumours, we performed a miRNA microarray analysis on 43 paired primary tumours (ten colon, ten bladder, 13 breast, and ten lung cancers) and one of their related metastatic lymph nodes. We identified a metastatic cancer miRNA signature comprising 15 overexpressed and 17 underexpressed miRNAs. Our results were confirmed by qRT‐PCR analysis. Among the miRNAs identified, some have a well‐characterized association with cancer progression, eg miR‐10b, miR‐21, miR‐30a, miR‐30e, miR‐125b, miR‐141, miR‐200b, miR‐200c, and miR‐205. To further support our data, we performed an immunohistochemical analysis for three well‐defined miRNA gene targets (PDCD4, DHFR, and HOXD10 genes) on a small series of paired colon, breast, and bladder cancers, and one of their metastatic lymph nodes. We found that the immunohistochemical expression of these targets significantly follows the corresponding miRNA deregulation. Our results suggest that specific miRNAs may be directly involved in cancer metastasis and that they may represent a novel diagnostic tool in the characterization of metastatic cancer gene targets. Copyright

Correlations Between O6-Methylguanine DNA Methyltransferase Promoter Methylation Status, 1p and 19q Deletions, and Response to Temozolomide in Anaplastic and Recurrent Oligodendroglioma: A Prospective GICNO Study

PURPOSE To date, no data are available on the relationship between 1p/19q deletions and the response to temozolomide (TMZ) in primary anaplastic oligodendroglioma (AO) and anaplastic oligoastrocytoma (AOA) recurrent after surgery and standard radiotherapy. The aim of this study was to evaluate correlations between 1p/19q deletions, O6-methylguanine DNA methyltransferase (MGMT) promoter methylation, and response rate to TMZ in this setting. PATIENTS AND METHODS From June 2000 to February 2005, 67 patients were enrolled; 39 patients (58%) had AO and 28 patients (42%) had AOA. All patients received 150 to 200 mg/m2 of TMZ every 28 days. Chromosome 1p and 19q deletions were detected by fluorescence in situ hybridization and MGMT promoter methylation was analyzed using methylation specific polymerase chain reaction. RESULTS The overall response rate was 46.3% (17 complete responses and 14 partial responses). The response rate was higher in patients with AO than in those with AOA (61.5% v 25%, P = .003). Combined 1p/19q allelic loss was found in 32 patients (47.8%), while MGMT methylation occurred in 37 (68.5%) of 54 assessable patients. 1p/19q loss was significantly correlated with response rate (P = .04), time-to-progression (P = .003), and overall survival (P = .0001). Despite the significant concordance found between MGMT promoter methylation and 1p/19q deletions (P = .02), MGMT promoter methylation showed only a borderline correlation with overall survival (P = .09). CONCLUSION TMZ is active in anaplastic oligodendroglial tumors treated at first recurrence. In this setting, 1p/19q allelic loss is an important predictive and prognostic factor. Further studies on MGMT promoter methylation should be performed in randomized trials to test its correlation with survival.

Embryonal tumors with abundant neuropil and true rosettes: a distinctive CNS primitive neuroectodermal tumor.

Embryonal neoplasms of the central nervous system (CNS) generally arise in the early years of life and behave in a clinically aggressive manner, but vary somewhat in their microscopic appearance. Several groups have reported examples of an embryonal tumor with combined histologic features of ependymoblastoma and neuroblastoma, a lesion referred to as “embryonal tumor with abundant neuropil and true rosettes” (ETANTR). Herein, we present 22 new cases, and additional clinical follow-up on our 7 initially reported cases, to better define the histologic features and clinical behavior of this distinctive neoplasm. It affects infants and arises most often in cerebral cortex, the cerebellum and brainstem being less frequent sites. Unlike other embryonal tumors of the CNS, girls are more commonly affected than boys. On neuroimaging, the tumors appear as large, demarcated, solid masses featuring patchy or no contrast enhancement. Five of our cases (18%) were at least partly cystic. Distinctive microscopic features include a prominent background of mature neuropil punctuated by true rosettes formed of pseudo-stratified embryonal cells circumferentially disposed about a central lumen (true rosettes). Of the 25 cases with available follow-up, 19 patients have died, their median survival being 9 months. Performed on 2 cases, cytogenetic analysis revealed extra copies of chromosome 2 in both. We believe that the ETANTR represents a histologically distinctive form of CNS embryonal tumor.

O6-methylguanine DNA-methyltransferase methylation status can change between first surgery for newly diagnosed glioblastoma and second surgery for recurrence: clinical implications

O(6)-methylguanine DNA-methyltransferase (MGMT) promoter methylation status is a prognostic factor in newly diagnosed glioblastoma patients. However, it is not yet clear whether, and if so how, MGMT methylation status may change. Moreover, it is unknown whether the prognostic role of this epigenetic feature is retained during the disease course. A retrospective analysis was made using a database of 614 glioblastoma patients treated prospectively from January 2000 to August 2008. We evaluated only patients who met the following inclusion criteria: age > or = 18 years; performance status 0-2; histological diagnosis of glioblastoma at both first and second surgery for recurrence; postoperative treatment consisting of: (i) radiotherapy (RT) followed by adjuvant temozolomide (TMZ) until 2005 and (ii) TMZ concurrent with and adjuvant to RT after 2005; a time interval > or = 3 months between first and second surgery. MGMT status was evaluated at first and second surgery in all 44 patients (M:F 32:12, median age: 49 years, range: 27-67 years). In 38 patients (86.4%), MGMT promoter status was assessable at both first and second surgery. MGMT methylation status, changed in 14 patients (37%) of second surgery samples and more frequently in methylated than in unmethylated patients (61.5% vs 24%, P = .03). The median survival was significantly influenced only by MGMT methylation status determined at first surgery (P = .04). Significant changes in MGMT methylation status during the course of GBM occur more frequently in MGMT methylated than unmethylated cases. MGMT methylation status determined at first surgery appears to be of prognostic value; however, it is not predictive of outcome following second surgery.

Temozolomide as a second-line systemic regimen in recurrent high-grade glioma: A phase II study

BACKGROUND To investigate the efficacy of temozolomide in relation to response rate, toxicity, time to progression. and median survival time, a phase II study was conducted in patients with recurrent high-grade glioma following surgery plus radiotherapy and first-line chemotherapy based on nitrosourea, procarbazine and vincristine. PATIENTS AND METHODS Forty-one patients with high-grade glioma, at second recurrence or progression, of which twenty-two (54%) had glioblastoma multiforme, ten (24%) anaplastic astrocytoma, and nine (22%) anaplastic oligodendroglioma were administered temozolomide, 150 mg/m2/daily for five days every four weeks. RESULTS Response was assessed in 40 patients. The overall response rate (complete + partial response) was 22.5% (95% confidence interval (CI): 9.5%-35%). The median time to progression for all 41 patients was 22.3 weeks; progression-free survival at 6 and 12 months was 48.5% and 34.7%, respectively. Median survival time was 37.1 weeks with 80.2% at 6 and 34.9% survival at 12 months. CONCLUSIONS On multivariate analysis, response to previous treatment was significant (P = 0.03) for time to progression and Karnofsky performance score for overall survivall (P = 0.002). Temozolomide gave a moderate response rate with acceptable toxicity as second-line chemotherapy in patients with recurrent high-grade glioma.

Learning curve and preliminary experience with da Vinci-assisted laparoscopic radical prostatectomy.

Objective: To report our initial experience in the treatment of prostate cancer with robotic-assisted laparoscopic radical prostatectomy (RALP), evaluating our results in terms of learning curve, postoperative outcomes and positive surgical margins. Material and Methods: From April 2005 to February 2006, a single surgeon performed 41 RALP using the da Vinci robot (Intuitive Surgical, Inc., Sunnyvale, Calif., USA). Clinical and pathological data were collected prospectively and analyzed by a researcher from outside our clinic. The main perioperative parameters assessed were the following: operative time, blood loss, transfusion rate, conversion rate, intra- and postoperative complications, hospitalization time, catheterization time, and positive surgical margin rate. To evaluate the learning curve, patients were stratified into three groups: from case 1 to 10 (group 1), from case 11 to 20 (group 2), and from case 21 to 41 (group C). Results: Median operative time was 210 min. Mean blood loss was 400 ml, with 9.8% of the patients receiving blood transfusions. Conversion to open surgery occurred in 2 cases (4.9%), while 4 postoperative complications (9.7%) were reported. Median times of hospitalization and catheterization were 7 days. Positive surgical margins were detected in 26.8% of the cases (6.9% among pT2 patients). Operative time (p < 0.001), blood loss (p = 0.02), transfusion rate (p = 0.006), and postoperative complication rates (p = 0.03) reduced along the learning curve. Conclusion: RALP is a feasible and reproducible technique, with a short learning curve and low perioperative complication rate. Even during the initial phase of the learning curve, good results were obtained with regard to postoperative complications and oncological outcome.

Loss of FHIT expression in transitional cell carcinoma of the urinary bladder

Cytogenetic and loss of heterozygosity (LOH) studies demonstrated chromosome 3p deletions in transitional cell carcinoma (TCC). We recently cloned the tumor suppressor gene FHIT (fragile histidine triad) at 3p14.2, one of the most frequently deleted chromosomal regions in TCC of the bladder, and showed that it is the target of environmental carcinogens. Abnormalities at the FHIT locus have been found in tumors of the lung, breast, cervix, head and neck, stomach, pancreas, and clear cell carcinoma of the kidney. We examined six TCC derived cell lines (SW780, T24, Hs228T, CRL7930, CRL7833, and HTB9) and 30 primary TCC of the bladder for the integrity of the FHIT transcript, using reverse transcriptase-polymerase chain reaction (RT-PCR) to investigate a potential role of the FHIT gene in TCC of the bladder. In addition, we tested expression of the Fhit protein in the six TCC-derived cell lines by Western blot analysis and in 85 specimens of primary TCCs by immunohistochemistry. Three of the six cell lines (50%) did not show the wild-type FHIT transcript, and Fhit protein was not detected in four of the six cell lines (67%) tested. Fhit expression also was correlated with pathological and clinical status. A significant correlation was observed between reduced Fhit expression and advanced stage of the tumors. Overall, 26 of 30 (87%) primary TCCs showed abnormal transcripts. Fhit protein was absent or greatly reduced in 61% of the TCCs analyzed by immunohistochemistry. These results suggested that loss of Fhit expression may be as important in the development of bladder cancer as it is for other neoplasms caused by environmental carcinogens.

Hypoxia and HIF1α Repress the Differentiative Effects of BMPs in High-Grade Glioma†‡§

Hypoxia commonly occurs in solid tumors of the central nervous system (CNS) and often interferes with therapies designed to stop their growth. We found that pediatric high‐grade glioma (HGG)‐derived precursors showed greater expansion under lower oxygen tension, typical of solid tumors, than normal CNS precursors. Hypoxia inhibited p53 activation and subsequent astroglial differentiation of HGG precursors. Surprisingly, although HGG precursors generated endogenous bone morphogenetic protein (BMP) signaling that promoted mitotic arrest under high oxygen tension, this signaling was actively repressed by hypoxia. An acute increase in oxygen tension led to Smad activation within 30 minutes, even in the absence of exogenous BMP treatment. Treatment with BMPs further promoted astroglial differentiation or death of HGG precursors under high oxygen tension, but this effect was inhibited under hypoxic conditions. Silencing of hypoxia‐inducible factor 1α (HIF1α) led to Smad activation even under hypoxic conditions, indicating that HIF1α is required for BMP repression. Conversely, BMP activation at high oxygen tension led to reciprocal degradation of HIF1α; this BMP‐induced degradation was inhibited in low oxygen. These results show a novel, mutually antagonistic interaction of hypoxia‐response and neural differentiation signals in HGG proliferation, and suggest differences between normal and HGG precursors that may be exploited for pediatric brain cancer therapy. STEM CELLS 2009;27:7–17

Lymphatic and vascular embolizations are independent predictive variables of inguinal lymph node involvement in patients with squamous cell carcinoma of the penis.

The objective of the current study was to identify independent clinical and pathologic variables that were predictive of lymph node involvement in patients with squamous cell carcinoma of the penis in a multicenter series with the intent to select patients who were suitable to undergo immediate inguinal lymphadenectomy.

Survival following adjuvant PCV or temozolomide for anaplastic astrocytoma

We compared survival in patients with anaplastic astrocytoma (AA) treated with adjuvant procarbazine, lomustine, and vincristine (PCV) with survival in patients treated with temozolomide. A retrospective analysis was made of patients with newly diagnosed AA treated with adjuvant postradiotherapy chemotherapy. Outcome analysis included progression-free survival and overall survival. The following prognostic factors were taken into account: patient age, extent of resection, performance status, presence of contrast enhancement in presurgical imaging, and type of adjuvant treatment. Among 109 AA patients, 49 were treated with PCV and 60 with temozolomide. The treatment groups were well matched for pretreatment characteristics, except for the presence of contrast enhancement. Age, extent of surgery, performance status, and presence of contrast enhancement were statistically significant prognostic factors according to the Cox model analysis of survival. Type of adjuvant chemotherapy was not a significant factor, either for progression-free survival or for overall survival. Hematological toxicity, nonhematological toxicity grades 3-4, and premature discontinuation due to toxicity were observed in 9%, 3% to 5%, and 37%, respectively, of cases in the PCV group versus 4% to 5%, 0, and 0, respectively, in the temozolomide group. Although the present study was not randomized, it was well designed, and it reports on two homogeneous and consecutive series of patients, for whom histology was verified to obtain survival data only for patients with AA following the recent WHO 2000 classification. Even if no survival advantage has been demonstrated for temozolomide versus PCV, we conclude that temozolomide should be preferred because of its greater tolerability.