Immature Stroma and Prognostic Profiling in Colorectal Carcinoma: Development and Validation of Novel Classification Systems

Many pathological characteristics have utility for predicting prognosis in colorectal carcinoma (CRC). Some of the most important include tumor stage (TS), lymph node status (LNS) and tumor budding (TB). Tumor budding is a phenomenon originally described in 1949 as sprouting. TB assessment is not always reliable however, as it is subject to high inter-observer variation. This finding persists despite the current trends for sub-specialty training in surgical pathology. In light of this, new and reproducible histological prognostic markers could change the way we diagnose and manage patients with colorectal carcinoma. Studies have shown that desmoplastic reaction (DR) categorization can actually outperform other conventional prognostic factors, including tumor budding and tumor stage in predicting disease-free survival (DFS). Our study aimed to evaluate and assess the prognostic value of desmoplastic reaction in an American cohort with colorectal cancer using 3 different stromal classification scoring systems. In all three stromal grading systems, immature stroma was the most significant independent prognostic factor in CRC. Currently, none of the reporting protocols for the College of American Pathologists, the Royal College of Pathologists of the United Kingdom, and the Japanese Society for Cancer report on the presence of immature stroma. Importantly, regarding the ability to predict survival outcomes, our novel classification system has the potential to outperform other scoring methodologies.

Ex vivo Efficacy of Anti-Cancer Drug PNC-27 in the Treatment of Patient-Derived Epithelial Ovarian Cancer

OBJECTIVE

Despite an 80% response rate to chemotherapy, epithelial ovarian cancer has the highest case fatality rate of all gynecologic malignancies. Several studies have shown the efficiency of anticancer peptides PNC-27 and PNC-28 in killing a variety of cancer cells selectively in vitro and in vivo. The purpose of this study was to evaluate the efficacy of PNC-27 against human primary epithelial ovarian cancer.

METHODS

We established primary cultures of freshly isolated epithelial ovarian cancer cells from patients with newly diagnosed ovarian cystadenocarcinomas. Two cell lines were obtained, one from mucinous cystadenocarcinoma, and the other from high-grade papillary serous carcinoma. The cancerous properties of these cells were characterized in vitro morphologically, by their growth requirements and serum independence. Treatment effects with PNC-27 were followed qualitatively by light microscopy, and quantitatively by measuring inhibition of cell growth using the MTT cell proliferation assay and direct cytotoxicity by measuring lactate dehydrogenase (LDH).

RESULTS

PNC-27 inhibits in a dose-dependent manner the growth of and is cytotoxic to human primary cancer cells that had been freshly isolated from two ovarian epithelial cancers. The results further show that the control peptide PNC-29 has no effect on the primary cancer cells. Our results also show that PNC-27 is cytotoxic to cells from long-established and chemotherapy-resistant human ovarian cancer cell lines.

CONCLUSION

These findings show, for the first time, the efficacy of PNC-27 on freshly isolated, primary human cancer cells. Our results indicate the potential of PNC-27 peptide as an efficient alternative treatment of previously untreated ovarian cancer as well as for ovarian cancers that have become resistant to present chemotherapies.

Abstract C44: Ex vivo cytotoxicity of PNC-27 on primary human ovarian and endometrial cancers

We have developed a series of anti-cancer peptide drugs, PNC-27 and PNC-28 from the MDM2- binding domain of the p53 protein (AA12–26 and 17–26, respectively) and a newly designed membrane residency peptide (MRP) that allows the drug to insert itself into cellular plasma membrane. To date, we have treated in vitro cells from over 20 different human epithelial cancer cell lines, including pancreatic, colon, lung, breast and ovarian cancer with PNC-27 and PNC-28. In all cases both peptides induce tumor cell necrosis within minutes to hours. Recent biophysical and ultrastructural studies have shown that cancer cell necrosis is due to the formation of transmembrane pores by PNC-peptide inducing direct cell lysis. Furthermore, we have found that PNC-28 destroys a highly metatstatic pancreatic cancer (BMRPA1.TUC-3) xenotransplanted into Nu/Nu mice. Remarkably, the PNC-peptides have no effect on the growth or viability of normal cells in culture such as human fibroblasts, keratinocytes and normal pancreatic acinar cells. Most importantly, the PNC-peptides have shown no effect on human umbilical-cord derived human hematopoetic stem cells in vitro to differentiate into mature blood cells and in vivo on blood cell differentials from tumor bearing and PNC-peptide treated animals. These results strongly indicate that PNC-27 and PNC-28 are potent anti-cancer drugs. The results strongly suggest the drugs' considerable potential against different epithelial cancers without exerting the limiting side effects of suppressing a patient's bone marrow, hematopoesis, normal cell growth and differentiation. Clearly, the cytotoxic efficacy of the PNC-peptides against long-established cancer cell lines is not directly transferable to a primary cancer in a future patient. Thus, to study the effect of PNC-peptide on a primary human cancer as close as possible to the in vivo (the tumor) situation, we freshly established in culture, under an IRB-approved protocol, cancer cells from the tissues of two primary human ovarian cancers and human uterine cancers. The cells released from the tumor tissue placed into a tissue culture dish were collected and their derivation as a homogenous cell population and from their respective tumors confirmed by immune-cytopathological comparative analysis. The cells' cancerous properties were confirmed in vitro within the first four passages (p) of the newly established primary cells when the cells' genomic makeup is still virtually identical (>99%) to that present in the tumor tissue per se. Cell growth and cell death in cells from p1–p4 and treated with PNC-27 or a control peptide PNC-29 were measured using MTT cell proliferation and LDH cytotoxicity assays. The results clearly demonstrate that PNC-27 effectively kills these primary human ovarian and uterine cancer cells in a dose-dependant manner with an LD50 of 100 and 150μg/ml, respectively. Throughout these experiments the effect of PNC-27 on the cancer cells' morphology was recorded, demonstrating the cells' complete disruption during the course of the treatment whereas the cancer cells treated with PNC-29 (up to 500μg/ml) remained morphologically indistinguishable from untreated cancer cells. These findings demonstrate for the first time the potentials of PNC-27 anti-cancer peptide as an efficient drug against freshly established and thus primary cells from these rather frequent human gynecological malignancies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr C44.

Induction of tyrosinase gene transcription in human iris organ cultures exposed to latanoprost

OBJECTIVE

Topical administration of latanoprost sometimes induces gradual iris darkening. The present study was undertaken to determine if latanoprost can increase transcription of the gene for tyrosinase, an important enzyme in the biosynthesis of melanin. Results from brown, hazel, and blue irides were compared.

METHODS

Iris tissue was isolated from 30 pairs of postmortem human donor eyes, and 2 iris segments from each eye were incubated in tissue culture medium supplemented with 200nM latanoprost acid or vehicle for 7 days. Tyrosinase messenger RNA (mRNA) was determined using real-time polymerase chain reaction analysis (TaqMan quantitative polymerase chain reaction). Results for tyrosinase mRNA were normalized according to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA in each sample.

RESULTS

Tyrosinase mRNA expression was similar in blue and hazel irides, and ranged from 0.7-fold to 12.6-fold greater than GAPDH expression. In contrast, control brown iris culture tyrosinase expression ranged from 6.4-fold to 265-fold greater than GAPDH expression. Induction of tyrosinase mRNA by latanoprost was below threshold in all the blue iris cultures (n = 8 pairs), present in 1 of 9 hazel iris cultures, and present in 5 of 13 brown iris cultures. Mean induction in the responding hazel iris cultures was 1.40-fold. Mean induction among the responding brown iris cultures was 2.97-fold.

CONCLUSIONS

These observations support the view that iris darkening associated with latanoprost treatment reflects induction of tyrosinase expression. Moreover, they suggest that the probability that latanoprost will increase tyrosinase expression is directly related to the magnitude of tyrosinase expression before treatments are initiated.

CLINICAL RELEVANCE

The variability of iris darkening with latanoprost may reflect natural variation in the basal transcription of tyrosinase.

Latanoprost and matrix metalloproteinase-1 in human choroid organ cultures

PURPOSE

Latanoprost, a prostaglandin F2a analogue and ocular hypotensive agent, alters extracellular matrix and matrix metalloproteinases (MMPs), including MMP-1, within tissues of the uveoscleral outflow pathway. In addition to these tissues, the anterior choroid also is exposed to fluid within the uveoscleral outflow pathway. The present study was undertaken to compare MMP-1 expression in the choroid with other uveoscleral pathway tissues and to determine the effect of latanoprost on MMP-1 expression in human choroid organ cultures.

METHODS

Choroid tissue explant cultures were generated and incubated with PhXA85, the biologically active form of latanoprost, or vehicle for 12 or 18 hours. Explant cultures from iris and ciliary body also were generated and exposed to PhXA85. Protein extracts of theses cultures, as well as from fresh tissues, were then probed for MMP-1 by Western blotting. All samples were normalized for protein content and reletive expression was evaluated by densitometry. Also, total RNA was harvested from fresh tissues or from cultures treated with PhXA85. The amount of MMP-1 mRNA in these samples was measured using real time polymerase chain reaction. These results were normalized according to simultaneous measurements of glyceraldehyde-3-phosphate dehydrogenase mRNA within the same samples.

RESULTS

Compared to the ciliary body, in which specific MMP-1 concentration (/total mg protein) was greatest, the specific MMP-1 concentrations within iris, anterior choroid, and posterior choroid were less by 24.7 +/- 0.69%, 40.7 +/- 1.04%, and 64.5 +/- 0.52%, respectively (mean +/- SD). The order of MMP-1 mRNA expression among these tissues from fresh eyes was ciliary body < anterior choroid < posterior choroid < iris. Treatment of ciliary body explant cultures with 200 nM PhXA85 for 12 hours increased MMP-1 protein content by 154 +/- 34% (P = 0.004, students t test, N = 3). In contrast, similar treatment of anterior choroid, posterior choroid, or iris explant cultures minimally changed MMP-1 protein content (23 +/- 22+/-, P = 0.124; 14 +/- 8%, P = 0.462; 27 +/- 16%, P = 0.037, respectively). Increased MMP-1 was observed in choroid cultures incubated for 18 hrs with 200 nM or 500 nM PhXA85. MMP-1 mRNA in 12 hour PhXA85-treated choroid cultures was the same or less than vehicle-treated cultures from 7 of 9 donors. In contrast, MMP-1 mRNA was increased in PhXA85-treated ciliary body cultures from 2 of 2 donors.

CONCLUSIONS

These results suggest that the capacity for latanoprost-mediated induction of MMP-1 within the choroid is less than within the ciliary muscle. Hence, it is unlikely that induction of MMP-1 in choroid plays as important a role in uveoscleral outflow modulation as induction of MMP-1 in the ciliary muscle.