Marcella Mottolese

The execution of the transcriptional axis mutant p53, E2F1 and ID4 promotes tumor neo-angiogenesis

ID4 (inhibitor of DNA binding 4) is a member of a family of proteins that function as dominant-negative regulators of basic helix-loop-helix transcription factors. Growing evidence links ID proteins to cell proliferation, differentiation and tumorigenesis. Here we identify ID4 as a transcriptional target of gain-of-function p53 mutants R175H, R273H and R280K. Depletion of mutant p53 protein severely impairs ID4 expression in proliferating tumor cells. The protein complex mutant p53–E2F1 assembles on specific regions of the ID4 promoter and positively controls ID4 expression. The ID4 protein binds to and stabilizes mRNAs encoding pro-angiogenic factors IL8 and GRO-α. This results in the increase of the angiogenic potential of cancer cells expressing mutant p53. These findings highlight the transcriptional axis mutant p53, E2F1 and ID4 as a still undefined molecular mechanism contributing to tumor neo-angiogenesis.

Immunohistochemical expression of p16 INK4a is predictive of HR-HPV infection in cervical low-grade lesions

The p16INK4a is a cyclin-dependent kinase inhibitor that decelerates the cell cycle by inactivating the cyclin-dependent kinases involved in the phosphorylation of the retinoblastoma protein (RB). Expression of E6 and E7 oncogenes of high-risk (HR) human papillomavirus (HPV), affecting the RB-p16 pathway, leads to p16 upregulation. Although it is widely reported that p16 is overexpressed in a high percentage of preneoplastic lesions and in almost all carcinomas of the uterine cervix, protein upregulation and its correlation with HPV infection in low-grade lesions is still being debated. In this study, we investigated in parallel, p16 expression and HPV infection in 100 cervical biopsies (17 normal tissues, 54 CIN1, 10 CIN2, 11 CIN3, eight invasive squamous cancers). Results obtained demonstrated that none of the 17 normal cervical tissues, evaluated by immunohistochemistry, presented p16 positivity whereas, starting from CIN1 (31%) to CIN2 (90%), CIN3 (100%) and carcinomas (100%), a constant and significant increase of protein overexpression (P<0.0001) was observed. In addition, p16 overexpression consistently showed elevated sensitivity (84%) and specificity (98%) in detecting HR-HPV infection with a high positive predictive value (97%) and negative predictive value (86%). Of interest, 93% of the p16-positive CIN1 were also HR-HPV infected. Our findings confirmed that p16 overexpression is associated to high-grade precancerous lesions and cervical carcinomas, and further demonstrated that immunohistochemical evaluation of p16 may be a useful biomarker in identifying HR-HPV-infected low-grade lesions.

Clinical outcome of patients with brain metastases from HER2-positive breast cancer treated with lapatinib and capecitabine

BACKGROUND In the present study, we investigated the clinical outcome of patients with brain metastases (BMs) from human epidermal growth factor receptor 2-positive (HER2+) breast cancer (BC) treated with lapatinib and capecitabine (LC). METHODS Of 81 HER2+ metastatic BC patients treated with LC at two Italian institutions, 30 patients with BMs eligible for the analysis were identified. All patients were pretreated with trastuzumab for metastatic disease. No patients had received prior lapatinib and/or capecitabine. RESULTS Median age was 45 years (range 24-75) and 26 of 30 patients (86.7%) had received prior cranial radiotherapy. In the 22 patients with BMs evaluable for response, 7 partial responses (31.8%) and 6 disease stabilizations (27.3%) were observed. Overall, the median brain-specific progression-free survival was 5.6 months (95% confidence interval 4.4-6.8). Patients treated with LC had a median overall survival (from the time of development of BMs) significantly longer compared with 23 patients treated with trastuzumab-based therapies only beyond brain progression (27.9 months versus 16.7 months, respectively, P = 0.01). CONCLUSIONS LC is active for BMs from HER2+ BC in patients not pretreated with either lapatinib or capecitabine. The introduction of LC after the development of BMs may further improve survival compared with trastuzumab-based therapies only beyond brain progression.

TAZ is required for metastatic activity and chemoresistance of breast cancer stem cells.

Metastatic growth in breast cancer (BC) has been proposed as an exclusive property of cancer stem cells (CSCs). However, formal proof of their identity as cells of origin of recurrences at distant sites and the molecular events that may contribute to tumor cell dissemination and metastasis development are yet to be elucidated. In this study, we analyzed a set of patient-derived breast cancer stem cell (BCSC) lines. We found that in vitro BCSCs exhibit a higher chemoresistance and migratory potential when compared with differentiated, nontumorigenic, breast cancer cells (dBCCs). By developing an in vivo metastatic model simulating the disease of patients with early BC, we observed that BCSCs is the only cell population endowed with metastatic potential. Gene-expression profile studies comparing metastagenic and non-metastagenic cells identified TAZ, a transducer of the Hippo pathway and biomechanical cues, as a central mediator of BCSCs metastatic ability involved in their chemoresistance and tumorigenic potential. Overexpression of TAZ in low-expressing dBCCs induced cell transformation and conferred tumorigenicity and migratory activity. Conversely, loss of TAZ in BCSCs severely impaired metastatic colonization and chemoresistance. In clinical data from 99 BC patients, high expression levels of TAZ were associated with shorter disease-free survival in multivariate analysis, thus indicating that TAZ may represent a novel independent negative prognostic factor. Overall, this study designates TAZ as a novel biomarker and a possible therapeutic target for BC.

Bcl-2 overexpression and hypoxia synergistically act to modulate vascular endothelial growth factor expression and in vivo angiogenesis in a breast carcinoma line.

We have previously demonstrated that bcl‐2 overexpression enhances the metastatic potential of the MCF7 ADR human breast cancer cell line resistant to adriamycin by inducing metastasis‐associated properties. To further elucidate the relationship between bcl‐2 expression and the metastatic potential of the MCF7 ADR line, we evaluated whether bcl‐2 could be also involved in the modulation of the angiogenic phenotype. Four bcl‐2‐overex‐pressing clones, a control transfectant clone, and the MCF7 ADR parental line were used for in vitro and in vivo experiments. Bcl‐2 overexpression enhanced the synthesis of the hypoxia‐stimulated VEGF protein and mRNA. Northern blot analysis demonstrated an increased VEGF mRNA expression in bcl‐2‐overex‐pressing clones, and reverse transcription‐polymer‐ase chain reaction showed higher levels of the VEGF121 and VEGF165 mRNA isoforms, which are the most active in eliciting angiogenesis. When incorporated into matrigel, supernatants of bcl‐2‐trans‐fected cells cultured under hypoxic conditions induced an increased angiogenic response in C57BL/6 mice compared with that of control clone. Tumors from bcl‐2 transfectants demonstrated increased VEGF expression and neovascularization as compared to the parental line, whereas the apoptosis in in vivo xenografts was similar in control and bcl‐2 transfectants. The effect of bcl‐2 on angiogenesis was not mediated by p53 protein. These results demonstrate that bcl‐2 and hypoxia can act synergis‐tically to modulate VEGF expression and the in vivo angiogenic response in the MCF7 ADR line.—Biroccio, A., Candiloro, A., Mottolese, M., Sapora, O., Albini, A., Zupi, G., Del Bufalo, D. Bcl‐2 overexpression and hypoxia synergistically act to modulate vascular endothelial growth factor expression and in vivo angiogenesis in a breast carcinoma line. FASEB J. 14, 652–660 (2000)

Cetuximab plus chronomodulated irinotecan, 5-fluorouracil, leucovorin and oxaliplatin as neoadjuvant chemotherapy in colorectal liver metastases: POCHER trial

Background:We assessed the effectiveness of cetuximab plus chronomodulated irinotecan, 5-fluorouracil (5-FU), leucovorin (FA) and oxaliplatin (L-OHP) (chrono-IFLO) administered as neoadjuvant chemotherapy to increase the resectability of colorectal liver metastases.Methods:This was a phase II prospective trial with rate of liver metastases resection as primary end point. Forty-three patients with unresectable metastases were enroled: 9 with metastases >5 cm; 29 with multinodular (>4) disease; 1 with hilar location; 4 with extrahepatic lung disease. Treatment consisted of cetuximab at day 1 plus chronomodulated irinotecan 5-FU, FA and L-OHP for 2–6 days every 2 weeks. After the first 17 patients, doses were reduced for irinotecan to 110 mg m−2, 5-FU to 550 mg m−2 per day and L-OHP to 15 mg m−2 per day.Results:Macroscopically complete resections were performed in 26 out of 43 patients (60%) after a median of 6 (range 3–15) cycles. Partial response was noticed in 34 patients (79%). Median overall survival was 37 months (95% CI: 21–53 months), with a 2-year survival of 68% in the entire population, 80.6% in resected patients and 47.1% in unresected patients (P=0.01). Grade 3/4 diarrhoea occurred in 93% and 36% of patients before and after dose reduction.Conclusion:Cetuximab plus chrono-IFLO achieved 60% complete resectability of colorectal liver metastases.

miR-204 targets Bcl-2 expression and enhances responsiveness of gastric cancer

Micro RNAs (miRs) are small non-coding RNAs aberrantly expressed in human tumors. Here, we aim to identify miRs whose deregulated expression leads to the activation of oncogenic pathways in human gastric cancers (GCs). Thirty nine out of 123 tumoral and matched uninvolved peritumoral gastric specimens from three independent European subsets of patients were analyzed for the expression of 851 human miRs using Agilent Platform. The remaining 84 samples were used to validate miRs differentially expressed between tumoral and matched peritumoral specimens by qPCR. miR-204 falls into a group of eight miRs differentially expressed between tumoral and peritumoral samples. Downregulation of miR-204 has prognostic value and correlates with increased staining of Bcl-2 protein in tumoral specimens. Ectopic expression of miR-204 inhibited colony forming ability, migration and tumor engraftment of GC cells. miR-204 targeted Bcl-2 messenger RNA and increased responsiveness of GC cells to 5-fluorouracil and oxaliplatin treatment. Ectopic expression of Bcl-2 protein counteracted miR-204 pro-apoptotic activity in response to 5-fluorouracil. Altogether, these findings suggest that modulation of aberrant expression of miR-204, which in turn releases oncogenic Bcl-2 protein activity might hold promise for preventive and therapeutic strategies of GC.

Changes in expression of alpha 6/beta 4 integrin heterodimer in primary and metastatic breast cancer.

The alpha 6/beta 4 integrin complex has been shown to be expressed in murine tissues at the basolateral aspect of most epithelial cells including the mammary epithelium, thus suggesting that this heterodimer may interact with components of the basement membrane. Because transformation of mammary epithelium frequently results in disappearance of basement membranes and loss of cell polarisation we have analysed in the present study whether expression of the alpha 6/beta 4 complex is altered in human breast tumours. The results of the present study confirm that in human mammary gland alpha 6 and beta 4 subunits colocalise at the basolateral aspect of the epithelium. While in benign breast lesions this distribution pattern remains mostly unchanged, in primary carcinomas the expression of both chains is either redistributed over the cells surface or significantly reduced. This altered pattern of expression is paralleled by the lack of detection of basement membrane laminin and collagen type IV. In metastatic lesions the expression of the heterodimer is maintained in most of the lymphnodal foci, but less frequently detected in metastasis localised in the pleural cavity and in parenchymal tissues. These findings indicate that in breast epithelium expression of the alpha 6/beta 4 heterodimer is modulated by the presence of basement membrane and is possibly influenced by microenvironmental factors as suggested by the different pattern of alpha 6/beta 4 expression in nodal and extranodal metastatic foci.

Prognostic relevance of altered Fas (CD95)‐system in human breast cancer

The Fas ligand (FasL) and its receptor Fas (APO‐1 or CD95) are members, respectively, of the tumor necrosis factor family that, upon interaction with each other, play a key role in the initiation of one apoptotic pathway. Faulty regulation of the Fas system has been described in a variety of human tumors with different histogenetic origin. Here, we describe the expression and distribution of Fas receptor and ligand pair antigens in surgical samples collected from a cohort of 186 patients bearing breast neoplasms (45 benign and 141 malignant lesions). Immunoperoxidase staining of formalin‐fixed tissues showed that 91.1% of benign lesions expressed Fas, which was present in only 56.7% of malignant tumors. On the other hand, FasL was found positive in 22.2% of benign neoplasms and up‐regulated in in situ as well as invasive carcinomas (53.9%). Moreover, in malignant tumors, the expression of receptor and ligand antigens appeared to be inversely related. When these findings were correlated with pathological parameters of prognostic relevance, a significant association was observed between FasL and the presence of metastatic lymph nodes and larger tumor size while Fas expression correlated to node‐negative status and smaller tumor size. Patients with Fas positive tumors exhibited longer disease‐free survival than those with Fas‐negative carcinoma while FasL did not influence patient outcome. These relationships indicate that benign and malignant mammary lesions are characterized by differential cellular expression of Fas and FasL and suggest that a neoplastic Fas negative/FasL positive phenotype may be linked to breast cancer progression. Int. J. Cancer (Pred. Oncol.) 89:127–132, 2000.

Diagnostic and prognostic value of peritoneal immunocytology in gastric cancer.

PURPOSE Among the clinical factors with a pivotal role in the prediction of outcome for patients with gastric cancer, intraperitoneal (i.p.) microscopic dissemination may represent an important cause of recurrences, even in the early stages of the disease. In this context, the cytologic examination of intraoperative peritoneal washings may be essential to identify metastatic free cells, although a number of false-negative cases may be encountered. PATIENTS AND METHODS To determine whether immunocytochemical (ICC) methods that used a panel of three monoclonal antibodies (MoAbs), B72.3, AR3, and BD5, directed to gastric cancer-associated antigens can improve peritoneal cytology by providing more accurate prognostic indications, we immunocytochemically and morphologically evaluated 144 peritoneal washings sampled from patients surgically treated for gastric cancer. RESULTS The ICC analysis allowed the identification of metastatic free peritoneal cells in 35% of the patients, with a 14% improvement over routine cytopathology (P < .0001). Furthermore, a 54-month survival analysis by Kaplan-Meier curves showed a statistically significant decrease in overall survival (OS) in patients with stages I through III disease with peritoneal microscopic disease detected morphologically and/or by ICC at the time of the primary surgery. CONCLUSION Our data indicate that the use of a combination of selected MoAbs may allow the identification of cytologically false-negative cases that provide valuable prognostic information. This may be useful to stratify patients on more adequate therapeutic trials.