Intratumoral expression profiling of genes involved in angiogenesis in colorectal cancer patients treated with chemotherapy plus the VEGFR inhibitor PTK787/ZK 222584 (vatalanib)

The phase III CONFIRM clinical trials demonstrated that metastatic colorectal cancer patients with elevated serum lactate dehydrogenase (LDH) had improved outcome when the vascular endothelial growth factor receptor (VEGFR) inhibitor PTK/ZK (Vatalanib) was added to FOLFOX4 chemotherapy. We investigated the hypothesis that high intratumoral expression of genes regulated by hypoxia-inducible factor-1 alpha (HIF1α), namely LDHA, glucose transporter-1 (GLUT-1), VEGFA, VEGFR1, and VEGFR2, were predictive of outcome in CONFIRM-1. Tumor tissue was isolated by laser-capture microdissection from 85 CONFIRM-1 tumor specimens; FOLFOX4/placebo n=42, FOLFOX4/PTK/ZK n=43. Gene expression was analyzed using quantitative RT-PCR. In univariate analyses, elevated mRNA expression of LDHA, GLUT-1, and VEGFR1 were associated with response to FOLFOX4/PTK/ZK. In univariate and multivariate analyses, elevated LDHA and VEGFR1 mRNA levels were associated with improved progression-free survival in FOLFOX4/PTK/ZK patients. Furthermore, increased HIF1α and VEGFR2 mRNA levels were associated with decreased survival in FOLFOX/placebo patients but not in patients who received FOLFOX4/PTK/ZK. These are the first data suggesting intratumoral mRNA expression of genes involved in angiogenesis/HIF pathway may predict outcome to VEGFR-inhibitors. Biomarkers that assist in directing VEGFR-inhibitors toward patients with an increased likelihood of benefit will improve the cost-effectiveness of these promising agents.

Successful control of intractable hypoglycemia using rapamycin in an 86-year-old man with a pancreatic insulin-secreting islet cell tumor and metastases

CONTEXT

Insulinomas are rare tumors of the pancreatic islet cells that produce insulin. Approximately 5 to 10% of these tumors are cancerous, and control of insulin secretion and hypoglycemia may be difficult in these patients. Malignant insulinomas generally respond poorly to traditional chemotherapeutic agent regimens. At present, streptozotocin is the only approved drug for the treatment of pancreatic islet cell tumors. SETTING AND PATIENT: This report describes a case of an elderly gentleman with a metastatic pancreatic insulinoma and severe hypoglycemia. A continuous infusion of octreotide lowered the blood glucose levels further. He required diazoxide, a thiazide diuretic, phenytoin, and a constant infusion of glucose to control the hypoglycemia and elevated insulin levels.

INTERVENTION

Rapamycin was administered at an oral dose of 2 mg/d.

RESULTS

On the mTOR (mammalian target of rapamycin) agent rapamycin, he was weaned off all drugs except for the thiazide diuretic and maintained euglycemia with a reduction of circulating insulin levels. He remained euglycemic for the past year with no evidence of tumor progression based on Octreoscan. His quality of life is excellent, and he remains active having recently completed a triathlon.

CONCLUSIONS

Rapamycin may provide a useful means of abrogating tumor growth and controlling hypoglycemia in malignant insulinomas by reducing the malignant beta-cell growth and proliferation as well as inhibiting insulin production.

Methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms associated with overall survival in women with metastatic colon cancer

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Background: Methylenetetrahydrofolate Reductase (MTHFR) is a key enzyme regulating intracellular folate pool, which affects DNA synthesis and methylation. Recent studies found folate deficiency induces DNA damage because of impaired nucleotide-excision repairs in mouse model. Two MTHFR gene polymorphisms, C677T and A1298C are linked to altered enzyme activity. Numerous studies have shown these two polymorphisms associated with colon cancer risk and response to fluorouracil-based treatment in advanced colon cancer patients. One epidemiology study also demonstrated 1298CC genotype to be associated with a significantly lower risk of colon cancer in women, but not men. We tested whether these two polymorphisms were associated with clinical outcome in metastatic colon cancer patients treated with 5-FU/Oxaliplatin. Methods: Between 1992 and 2003, a total of 318 patients with metastatic colon cancer treated at the University of Southern California/Norris Comprehensive Cancer Center (USC/NCCC) or the Los Angeles County/University of Southern California Medical Center (LAC/USCMC), were eligible for this study. Peripheral blood samples were collected from each patient and genomic DNA was extracted from white blood cells using the QiaAmp kit (Qiagen, Valencia, CA). Two MTHFR gene polymorphisms (C677T, A1298C) were tested by PCR-RFLP method. Results: MTHFR A1298C gene polymorphism showed statistically significant differences in overall survival (OS) in female patients with metastatic colon cancer (P=0.025, logrank test). Patients with the AA genotype had an 18.7 months median OS compared with the heterozygous AC genotype, which had a 14.3 months median OS and the CC genotype, which had a 15.9 months median OS. Conclusions: There is no significant difference in clinical outcome in male patients. However, female metastatic colon cancer patients with a MTHFR A1298C polymorphism AA genotype have significantly better overall survival than those with heterozygous AC genotype or CC genotype. This data supports the role of MTHFR polymorphisms as an independent prognostic marker in female patients with metastatic colon cancer. Further prospective study is needed to confirm these preliminary findings.

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Thymidylate synthase gene polymorphism determines response and toxicity of 5-FU chemotherapy

Thymidylate synthase (TS) catalyses the conversion of deoxy-uridylate to deoxy-thymidylate and is essential for DNA synthesis. The human TS gene promoter is polymorphic, having either double or triple tandem repeats of a 28-bp sequence. Here we determined the significance of this polymorphism in humans and its prediction for clinical outcome of patients with metastatic colorectal cancer treated with 5-fluorouracil. The TS mRNA level was analyzed using RT-PCR. Individuals homozygous for the triple repeat variant (L/L) had 3.6 times higher TS mRNA levels compared to those homozygous for the double repeat variant (S/S) in tumor tissue (P = 0.004). We tested 50 patients with disseminated colorectal cancer who received 5-FU treatment to determine whether this TS polymorphism will predict clinical outcome. We found individuals with S/S genotype had a response rate of 50% (4/8) when compared to 9% (2/22) in those with L/L and 15% (3/20) in those with S/L genotype (P = 0.041). Patients with L/L had less severe side effects to 5-FU (P = 0.008). The data suggest that genotyping for the TS polymorphism may have the potential to identify patients more likely to respond to 5-FU based chemotherapy.

dUTP nucleotidohydrolase isoform expression in normal and neoplastic tissues: association with survival and response to 5-fluorouracil in colorectal cancer

Aberrant dUTP metabolism plays a significant role in the underlying molecular mechanisms of cell killing mediated by inhibitors of thymidylate biosynthesis. dUTP nucleotidohydrolase (dUTPase) is the key regulator of dUTP pools, and significant evidence exists suggesting that the expression of this enzyme may be an important determinant of cytotoxicity mediated by inhibitors of thymidylate synthase (TS). In this study, we have determined the expression patterns of dUTPase in normal and neoplastic tissues and examined the association between dUTPase expression and response to 5-fluorouracil (5-FU)-based chemotherapy and overall survival in colorectal cancer. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded tissue sections using a monoclonal antibody (MAb), DUT415, that cross-reacts with both nuclear and mitochondrial isoforms of human dUTPase. Nuclear and cytoplasmic staining was observed in both normal and neoplastic tissues. In normal tissues, nuclear dUTPase staining was observed exclusively in replicating cell types. This observation is in agreement with cell culture studies where expression of the nuclear isoform (DUT-N) is proliferation dependent In contrast, cytoplasmic expression of dUTPase does not correlate with proliferation status and was observed in tissues rich in mitochondria. Consistent with this observation, cell culture studies reveal that the mitochondrial isoform (DUT-M) is expressed constitutively, independent of cell cycle status. These data suggest that in normal tissues, nuclear staining with the DUT415 antibody represents the DUT-N isoform, whereas cytoplasmic staining represents the DUT-M isoform. In colon cancer tumor specimens, expression of dUTPase was shown to be highly variable in both amount and intracellular localization. Patterns of dUTPase protein expression observed included exclusive nuclear, exclusive cytoplasmic, and combined nuclear and cytoplasmic staining. Thus, immunohistochemical detection of dUTPase in colon cancers provides distinct intracellular phenotypes of expression that may be of significant prognostic value. To examine the association between dUTPase expression and response to 5-FU-based chemotherapy and overall survival, we initiated a retrospective study including tumor specimens from 20 patients who had received protracted infusion of 5-FU and leucovorin for treatment of metastatic colon cancer. Positive nuclear staining was found in 8 patients, whereas 12 lacked nuclear expression. Of the patients lacking nuclear dUTPase expression, 6 responded to 5-FU-based chemotherapy, 4 had stable disease, and 2 had progressive disease. Of the patients presenting positive nuclear dUTPase expression, 0 responded to chemotherapy, 1 had stable disease, and 7 had progressive disease (P = 0.005). The median survival for patients with tumors lacking nuclear staining was 8.5 months and 6.9 months for patients with tumors demonstrating positive nuclear dUTPase expression (P = 0.09). Time to progression was significantly longer for patients with tumors lacking nuclear staining (P = 0.017). Variable cytoplasmic dUTPase expression was observed in these tumors; however, there was no apparent association with clinical response or survival in this limited study. Nuclear dUTPase staining within these tumors was also associated with TS gene expression (P = 0.06). This study demonstrates that low intratumoral levels of nuclear dUTPase protein expression is associated with response to 5-FU-based chemotherapy, greater time to progression, and greater overall survival in colorectal cancer. Conversely, high levels of nuclear dUTPase protein expression predict for tumor resistance to chemotherapy, shorter time to progression, and shorter overall survival. This report represents the first clinical study implicating dUTPase overexpression as a mechanism of resistance to TS inhibitor-based chemotherapy.

Adenocarcinoma simulating mesothelioma: a clinicopathologic and immunohistochemical study of 29 cases

We report 29 cases of adenocarcinomas whose clinical, gross, and microscopic appearance resembled diffuse malignant pleural mesothelioma. Initial criteria for inclusion in the study included availability of an open pleural biopsy or decortication specimen and microscopic evidence of neutral (periodic acid-Schiff positive) mucin in the tumor. The median age of the patients was 63 years (range, 31 to 78 years), with a peak age in the seventh decade. There were 24 men and five women. Thirteen of them had a history of smoking; six (21%) had possible or definite occupational exposure to asbestos. Three (21%) of 14 lung specimens showed ferruginous bodies and two (14%) showed microscopic evidence of asbestosis. At least 25 patients had pleural effusion, most typically unilateral. Needle biopsy of pleura showed malignancy in 10 (77%) of 13 cases. Most (20 of 29) patients underwent pleural stripping. Radiotherapy and chemotherapy was each given to three patients without effect. Median survival by Kaplan-Meier estimate was 8 months, with an 18-month survival of 13%. Histologically, glands (23 cases), nests (13 cases), tubulopapillary arrays (12 cases), or sheets (eight cases) of tumor cells were found. Spindling of neoplastic cells was seen in 10% of cases. Three (21%) of 14 lung specimens showed a subpleural adenocarcinoma. Antibodies to polyclonal CEA, Ber-EP4, Leu-M1, and B72.3 were positive in 94%, 56%, 50%, and 44% of cases, respectively. All but one of the cases stained with two or more of the antibodies CEA, Ber-EP4, Leu-M1, or B72.3. This study indicates that adenocarcinomas simulating mesothelioma are aggressive variants of peripheral adenocarcinomas with a poor prognosis, that they can show pathological evidence of asbestos exposure in a subset of cases, and that immunohistochemical and histochemical stains are useful in their differential diagnosis with diffuse malignant mesotheliomas.

Analysis of physician attitudes concerning requests for autopsy

To quantify the role of failure to request consent as a determinant of the autopsy rate, questionnaires asking whether an autopsy had been requested and the reasons for that decision were distributed to primary physicians after each death in a consecutive series of 75 patient deaths. Autopsies were requested in only 56% of cases. Common reasons to request an autopsy included unanswered medical questions (37%), medical education (22%), research protocol participation (16%), or routine policy (14%). When autopsies were not requested, the most common reason was the belief that there were no outstanding medical questions (64%). Follow-up interviews with 14 oncologists and hematologists revealed that 8 generally request autopsies (usually to contribute to medical education or to discover unexpected findings) and 6 generally do not (usually because no unexpected findings are anticipated). Attempts to increase the current low autopsy rate should address the question of when and why physicians are willing to request this procedure.

Secretion of prorenin by a virilizing ovarian tumor

A 53-year-old normotensive, normokalemic female presented with a 6-month history of virilization. Estradiol, LH, FSH, urinary-free cortisol, and DHEA-S levels were normal. Pelvic ultrasound and computerized tomography were also within normal limits. Her serum testosterone (551 ng/dl; nl, 20-70) and plasma prorenin (124 ng AI/ml/hr; nl, less than 50) levels were elevated. At surgery, a lipoid/steroid cell tumor of the right ovary was removed. Postoperative testosterone and prorenin levels were normal. Ovarian tumor cells, in culture, produced large amounts of prorenin. Immunohistochemistry localized prorenin and/or renin to tumor cells. Determining plasma prorenin levels may be a useful adjunct in diagnosing or following patients with nonepithelial ovarian tumors. A larger clinical study of prorenin levels in patients with such tumors is needed.

The effects of extracorporeal shock wave lithotripsy on renal growth, function and arterial blood pressure in an animal model

The long-term effects of extracorporeal shock wave lithotripsy (ESWL*) on children treated for renal calculi are unclear. To study the long-term bio-effects of this mode of treatment on the immature animal we evaluated 30 New Zealand white rabbits at 7 weeks of age for weight, serum blood urea nitrogen and creatinine, and arterial blood pressure after which they underwent left nephrectomy. Each group of 5 rabbits received ESWL of varying levels (500 to 3,000 shock waves) to the remaining right kidney using the Northgate SD3 lithotriptor (spark gap mediated). One control group received no shock waves. At maturity (16 weeks) the aforementioned parameters were measured again, and the kidneys and any grossly abnormal adjacent organs were examined. We found no significant change in total animal growth, renal growth, renal function or perirenal organs in the post-ESWL groups versus the control group. All post-ESWL groups had an increase in mean arterial blood pressure versus the control group with 3 of 6 groups showing significant increases (p less than 0.05). Histological renal changes, seen at all energy levels of ESWL delivered, included interstitial fibrosis, tubular atrophy, glomeruli destruction, capsular thickening, perivascular fibrosis and mild arteriole wall thickening. Changes were proportional to the number of shocks received. We conclude that ESWL delivered to immature animals does not significantly affect renal growth and function but it can cause significant permanent histological renal changes even at low doses and may result in an increase in adult mean arterial blood pressure.

Total pelvic exenteration with simultaneous bowel and urinary reconstruction

The technique of total pelvic exenteration with simultaneous bowel and urinary reconstruction is described as a surgical option for the management of pelvic sarcoma in adults and for highly selected patients with other types of advanced pelvic malignancy. The surgical technique is presented in detail as performed in a 43-year-old man who presented with extensive primitive pelvic sarcoma. We believe that this approach may provide the benefits of an exenterative operation without the undesirable psychosocial sequelae of a permanent colostomy and external urinary diversion.

Detection of occult CNS involvement of follicular small cleaved lymphoma by the polymerase chain reaction

A patient with follicular small cleaved lymphoma presented with an unusual clinical relapse in the central nervous system (CNS) without morphologic evidence of lymphoma cells in the cerebral spinal fluid (CSF). Molecular genetic analysis of the small number of cells in the CSF after in vitro DNA amplification by the polymerase chain reaction demonstrated the presence of an abnormal translocation sequence between chromosomes 14 and 18. A similar translocation could be detected from the original fixed archival lymph node biopsy and from a small proportion of circulating mononuclear cells. These results indicated that occult lymphoma cells were present in the CSF and peripheral blood. Secondary CNS lymphoma involvement was identified at autopsy. This case demonstrates the enhanced sensitivity of lymphoma diagnosis from poorly cellular specimens after in vitro DNA amplification.

Extrarenal renin-secreting tumors: insights into hypertension and ovarian renin production

Although renin-secreting tumors are rare, they must be considered in the differential diagnosis of hypertension associated with hypokalemia, which occurs commonly in the hypertensive population. The finding of an ovarian renin-secreting tumor emphasizes the potential importance of the ovary as an extrarenal source of renin; the local ovarian renin-angiotensin system may play a key role in reproductive function by regulating vascular reactivity, local blood flow, steroidogenesis and other physiologic effects. In the illustrative case presented, a renin-secreting ovarian leiomyosarcoma was obtained from a women who presented with hypertension and hypokalemia. Plasma prorenin levels were markedly elevated. Tumor excision was quickly followed by a fall in prorenin levels and tumor recurrence was accompanied by an increase in prorenin levels. Active renin concentration in the tumor homogenates was similar to that found in kidney homogenates while the tissue prorenin concentration was approximately 20 times that found in kidney tissue. When cultured for up to 4 weeks, ovarian tumor cells secreted greater than 95% prorenin. Immunoblot analysis demonstrated that tumor renin had a molecular weight of 47,000, similar to that of human recombinant prorenin. Immunohistochemical staining of tumor tissue with antibodies against human renal renin at the electron microscopic level demonstrated the presence of renin primarily in membrane-bound vesicles and rarely in dense-core secretory granules. These findings suggest that prorenin in this ovarian tumor was secreted by the constitutive pathway, which is mediated by these amorphous vesicles.

A phase 1a clinical trial of LYM-1 monoclonal antibody serotherapy in patients with refractory B cell malignancies

Ten patients with refractory B cell lymphomas were treated with weekly intravenous infusions of escalating doses of murine monoclonal antibody (MoAb) LYM-1 over four weeks. LYM-1 is a recently developed IgG2a murine MoAb that recognizes a polymorphic HLA-Dr antigen on surfaces of normal and malignant B cells but does not bind to any other normal tissues. MoAb LYM-1 has several advantages for serotherapy, since the antigen it recognizes is not shed from the cell surface and does not modulate in response to MoAb therapy. Furthermore, in vitro studies have indicated significant anti-tumour activity against lymphoma cell lines. In the current trial, dose-dependent levels of free LYM-1 were detected in the serum of all patients, but penetration of extravascular tumour tissues was poor. No significant toxicity or human anti-mouse antibody responses were observed in any patient. Clinical responses were minor and appeared to correlate with the number of infiltrating T cells seen in the initial lymphoma specimens. LYM-1 appears to be well-tolerated and has demonstrated several potential advantages as a therapeutic agent in patients with lymphoma. The mechanism of anti-tumour effect and plans for further clinical studies are discussed.

Intermediate filament expression in astrocytic neoplasms

Immunohistochemical analysis of 30 paraffin-embedded astrocytic neoplasms was performed to correlate the expression of intermediate filament proteins with histologic subtype. Each tumor was studied with monoclonal antibodies to keratin, vimentin, desmin, 200-kd neurofilament protein, and glial fibrillary acidic protein (GFAP). Immunoreactivity with the anti-keratin monoclonal antibodies AE1 and AE3 was demonstrated in 24 cases (80%) including 4 of 6 (66%) well-differentiated astrocytomas (WDAs), 10 of 12 (83%) anaplastic astrocytomas (ANAs), and 10 of 12 (83%) glioblastomas multiforme (GBMs). These cases were further studied with the monoclonal antikeratin antibodies 34 beta E12 and 34 beta H11. Of the 24 AE1/AE3-positive cases, 14 (58%) reacted with 34 beta E12. None of the cases was reactive with 34 beta H11. Vimentin expression was demonstrated in 24 cases (80%), including 2 of 6 (33%) WDAs, 11 of 12 (92%) ANAs, and 11 of 12 (92%) GBMs. Coexpression of keratin and vimentin was observed in 20 cases (67%), including 2 of 6 WDAs, 9 of 12 (75%) ANAs, and 9 of 12 (75%) GBMs. Immunoreactivity with GFAP antibody was present in all 30 (100%) cases, but none of the tumors was reactive with antibodies to desmin or 200-kd neurofilament protein. These findings demonstrate that expression of both keratin and vimentin intermediate filaments is common in astrocytic neoplasms regardless of histologic grade.

Successful therapy of natural killer-resistant pulmonary metastases by the synergism of gamma-interferon with tumor necrosis factor and interleukin-2 in mice

The problem associated with lymphokine (gamma-interferon, interleukin-2, and tumor necrosis factor) therapy in cancer is that high toxic doses of these lymphokines must be administered for any significant antitumor results. Therefore this study was undertaken to investigate the antitumor efficacy of these lymphokines in a disseminated pulmonary metastasis when used in combination with each other at dosages well below the toxic level. The role of the immune system of the host, sequencing of lymphokines, and histopathological aspects of lymphokine therapy were also investigated.

Therapy of disseminated NK-resistant tumor by the synergistic effects of recombinant interleukin-2 and tumor necrosis factor

Tumor necrosis factor and interleukin-2 each in recombinant form have antitumor activity against established tumors if used in high enough dosages. The problem associated with such high dosages is the high degree of toxicity and expense encountered. Therefore, this study was undertaken to look at the antitumor efficacy of these two lymphokines when used together at dosages well below the toxic levels. Our results using recombinant human interleukin-2 (IL-2) and recombinant human tumor necrosis factor (TNF) against established methylcholanthrene-induced fibrosarcoma (MCA sarcoma) pulmonary metastases showed that TNF and IL-2 therapy at low nontoxic dosages alone did not produce significant tumor regression, but when combined at the same dosage synergize producing significant antitumor effects in mice induced with MCA sarcoma. This was also evident from histopathological examination of the lungs where the maximum tumor reduction along with the maximum lymphocytic infiltration into tumor was seen when TNF and IL-2 were combined. In this tumor regression, inherent immunity of the treated mice was needed, since in those mice in which we induced immunosuppression by using radiation, tumor regression was not seen when TNF and IL-2 therapy was combined in the doses efficacious in immunocompetent mice. Tumor regression is also dependent on the sequence of administration of IL-2 and TNF, since when IL-2 was administered before TNF, the tumor regression was more significant than when TNF was administered before IL-2 or when both were administered simultaneously to mice with established pulmonary tumors. Therefore the synergistic effect of IL-2 and TNF could be used as an efficacious but inexpensive and nontoxic alternative to therapy with lymphokine activated killer (LAK) cells + IL-2.

Human ovarian theca cells are a source of renin

Human ovarian follicular fluid contains renin-like activity. In normal women, circulating levels of prorenin, the biosynthetic precursor of renin (EC 3.4.23.15), change in parallel with changes in progesterone during the menstrual cycle. Therefore, the ovary has been implicated as a source of plasma prorenin. In the present studies, we report the finding of high concentrations of prorenin in human ovarian follicular fluid (3000 ng.ml-1.hr-1 vs. 10-40 ng.ml-1.hr-1 in normal human plasma) obtained from follicles of women prepared for in vitro fertilization. The inactive renin-like enzyme was identified as prorenin by its activation characteristics, its molecular weight of 47,000, which is the same as that for recombinant prorenin, and its cross-reactivity with human renal renin antibodies. Culture of isolated human theca cells and isolated granulosa cells indicated that prorenin is secreted by theca cells but not by granulosa cells. Prorenin production by theca cells peaked during the first 10 days of culture and gradually decreased by 17 days. Active renin levels were 10% or less of the prorenin levels. Prorenin was barely detectable in medium from granulosa cells cultured for 24 days. Immunohistochemical staining of human ovaries (n = 5) with anti-human renin antibody demonstrated the presence of renin primarily in theca cells. These studies suggest that the theca cell is the source of the large quantities of prorenin in human ovarian follicular fluid.