The small splice variant of HPV16 E6, E6, reduces tumor formation in cervical carcinoma xenografts.

High-risk types of human papillomavirus (HPV) cause nearly all cases of cervical cancer. The E6 oncoprotein is produced as a full-length variant (E6) as well as several shorter isoforms (E6). E6 inhibits certain oncogenic activities of E6, suggesting that it might play an anti-oncogenic role in vivo. To test this, we created E6-expressing SiHa (HPV(+)) and C33A (HPV(-)) cells, then examined the ability of both the parental and E6-expressing cells to form tumors in nude mice. We found that over-expression of E6 indeed decreased the growth of tumors derived from both SiHa and C33A cells, with the reduction greatest in tumors derived from E6-expressing SiHa cells. These findings point to multiple anti-oncogenic characteristics of E6, some of which likely involve down-regulation of the full-length isoform, and others that are independent of HPV. These data represent the first demonstration of biologically-relevant E6 activities distinct from those of the full-length isoform in vivo.

Techniques of hepatic resection.

Liver resections are high risk procedures performed by experienced surgeons. The role of liver resection in malignant disease has changed over the last 100 years with great improvement in morbidity, mortality and long term survival. New understanding in liver anatomy, improved perioperative care, anesthesia techniques, and technological advances has improved this aspect of patient care. With improved techniques, patients previously considered unresectable have an opportunity to undergo curative surgery. This review article describes the various approaches and techniques for liver resection. The relevant anatomy and terminology of hepatic resections is discussed, as well as the role of anatomic vs. nonanatomic resection. Methods of vascular control are examined and the multiple strategies of parenchymal transection are compared, as well as minimally-invasive techniques. Finally, a brief review of the authors' practice in terms of surgical technique is offered.

RASSF1C modulates the expression of a stem cell renewal gene, PIWIL1.

BACKGROUND: RASSF1A and RASSF1C are two major isoforms encoded by the Ras association domain family 1 (RASSF1) gene through alternative promoter selection and mRNA splicing. RASSF1A is a well established tumor suppressor gene. Unlike RASSF1A, RASSF1C appears to have growth promoting actions in lung cancer. In this article, we report on the identification of novel RASSF1C target genes in non small cell lung cancer (NSCLC). METHODS: Over-expression and siRNA techniques were used to alter RASSF1C expression in human lung cancer cells, and Affymetrix-microarray study was conducted using NCI-H1299 cells over-expressing RASSF1C to identify RASSF1C target genes. RESULTS: The microarray study intriguingly shows that RASSF1C modulates the expression of a number of genes that are involved in cancer development, cell growth and proliferation, cell death, and cell cycle. We have validated the expression of some target genes using qRT-PCR. We demonstrate that RASSF1C over-expression increases, and silencing of RASSF1C decreases, the expression of PIWIL1 gene in NSCLC cells using qRT-PCR, immunostaining, and Western blot analysis. We also show that RASSF1C over-expression induces phosphorylation of ERK1/2 in lung cancer cells, and inhibition of the MEK-ERK1/2 pathway suppresses the expression of PIWIL1 gene expression, suggesting that RASSF1C may exert its activities on some target genes such as PIWIL1 through the activation of the MEK-ERK1/2 pathway. Also, PIWIL1 expression is elevated in lung cancer cell lines compared to normal lung epithelial cells. CONCLUSIONS: Taken together, our findings provide significant data to propose a model for investigating the role of RASSF1C/PIWIL1 proteins in initiation and progression of lung cancer.

Potential impact of USPSTF recommendations on early diagnosis of breast cancer.

OBJECTIVE: Current US Preventive Services Task Force (USPSTF) guidelines recommend against routine screening mammography in women aged 40-49 years. However, diagnosis of early-stage breast cancer relies on mammographic screening for detection. We hypothesized that screening at younger age may be important for detecting earlier and more treatable cancers for women in different demographic groups. METHODS: All women with ductal carcinoma in situ (DCIS) or T1N0 breast cancer between 2004 and 2008 in the California Cancer Registry were evaluated. Patients were divided into: (1) women aged 40-49 years, who would be excluded from USPSTF recommendations for screening, and (2) women aged 50-74 years, who are recommended for screening. Patients in the two age groups were compared by race/ethnicity, socioeconomic status (SES), and hormone receptor (HR), human epidermal growth factor receptor 2 (HER-2), and triple-negative (TN) status. RESULTS: Of 46,691 patients identified, 22.6% were aged 40-49 years, and 77.4% were aged 50-74 years. Younger women with DCIS had statistically higher odds of being HR positive and having higher SES, and Hispanic and Asian/Pacific Islander (PI) race/ethnicity, while younger women diagnosed with T1N0 breast cancer had higher odds of being HR positive, HER-2 positive, and triple negative and of having higher SES and non-white race/ethnicity. CONCLUSIONS: Young Hispanic, Asian/PI, and non-Hispanic (NH) Black women in California have greater odds of being diagnosed with early breast cancer than their older counterparts. Excluding 40-49-year-old women from screening could impact early diagnosis of HR-positive, HER-2-positive, and TN tumors. Implementation of USPSTF recommendations could disproportionately impact non-white women and potentially lead to more advanced presentation at diagnosis.

Ras-association domain family 1C protein promotes breast cancer cell migration and attenuates apoptosis.

BACKGROUND: The Ras association domain family 1 (RASSF1) gene is a Ras effector encoding two major mRNA forms, RASSF1A and RASSF1C, derived by alternative promoter selection and alternative mRNA splicing. RASSF1A is a tumor suppressor gene. However, very little is known about the function of RASSF1C both in normal and transformed cells. METHODS: Gene silencing and over-expression techniques were used to modulate RASSF1C expression in human breast cancer cells. Affymetrix-microarray analysis was performed using T47D cells over-expressing RASSF1C to identify RASSF1C target genes. RT-PCR and western blot techniques were used to validate target gene expression. Cell invasion and apoptosis assays were also performed. RESULTS: In this article, we report the effects of altering RASSF1C expression in human breast cancer cells. We found that silencing RASSF1C mRNA in breast cancer cell lines (MDA-MB231 and T47D) caused a small but significant decrease in cell proliferation. Conversely, inducible over-expression of RASSF1C in breast cancer cells (MDA-MB231 and T47D) resulted in a small increase in cell proliferation. We also report on the identification of novel RASSF1C target genes. RASSF1C down-regulates several pro-apoptotic and tumor suppressor genes and up-regulates several growth promoting genes in breast cancer cells. We further show that down-regulation of caspase 3 via overexpression of RASSF1C reduces breast cancer cells' sensitivity to the apoptosis inducing agent, etoposide. Furthermore, we found that RASSF1C over-expression enhances T47D cell invasion/migration in vitro. CONCLUSION: Together, our findings suggest that RASSF1C, unlike RASSF1A, is not a tumor suppressor, but instead may play a role in stimulating metastasis and survival in breast cancer cells.

Antibody-mediated FOXP3 protein therapy induces apoptosis in cancer cells in vitro and inhibits metastasis in vivo.

In addition to its immune suppressive function in T-regulatory cells, the nuclear transcription factor, FOXP3, has been identified as a tumor suppressor. To evaluate the clinical efficacy of monoclonal antibody (mAb) 3E10 Fv antibody-mediated FOXP3 protein therapy of cancer, the Fv-FOXP3 fusion protein produced in Pichia pastoris was tested on breast, ovarian, and colon cancer cells in vitro, and with colon cancer cells in vivo in a mouse model of colon cancer metastasis to liver. Treatment with Fv-FOXP3 resulted in dose-dependent cell death of cancer cells in vitro. Apoptosis was established as a mechanism of cell death by demonstrating increased production of the p17 activated fragment of caspase-3 by cancer cells in response to Fv-FOXP3 and inhibition of cell killing by the caspase inhibitor, Z-VAD-FMK. Fv-FOXP3 treatment resulted in clinically significant reduction in tumor burden in a syngeneic model of colon cancer metastasis to liver in Balb/c mice. These results represent the first demonstration of effective full-length FOXP3 protein therapy and emphasize the clinical potential of mAb 3E10 as an intracellular and intranuclear delivery vehicle of FOXP3 for prevention and treatment of cancer metastasis.

Antibody-mediated p53 protein therapy prevents liver metastasis in vivo.

To evaluate the clinical efficacy of monoclonal antibody (mAb) 3E10 Fv antibody-mediated p53 protein therapy, an Fv-p53 fusion protein produced in Pichia pastoris was tested on CT26.CL25 colon cancer cells in vitro and in vivo in a mouse model of colon cancer metastasis to the liver. In vitro experiments showed killing of CT26.CL25 cells by Fv-p53 but not Fv or p53 alone, and immunohistochemical staining confirmed that Fv was required for transport of p53 into cells. Prevention of liver metastasis in vivo was tested by splenic injection of 100 nmol/L Fv-p53 10 min and 1 week after injection of CT26.CL25 cancer cells into the portal vein of BALB/c mice. Mice were sacrificed 1 week after the second injection of Fv-p53 and assigned a quantitative metastasis score. Control mice had an average metastasis score of 3.3 +/- 1.3, whereas mice treated with Fv-p53 had an average metastasis score of 0.8 +/- 0.4 (P = 0.004). These results indicate that Fv-p53 treatment had a profound effect on liver metastasis and represent the first demonstration of effective full-length p53 protein therapy in vivo. mAb 3E10 Fv has significant clinical potential as a mediator of intracellular and intranuclear delivery of p53 for prevention and treatment of cancer metastasis.