The feasibility of targeted selective gene therapy of the hair follicle

Loss of hair and hair colour is associated with ageing, and when it involves the scalp hair, it can be distressing to both sexes. Hair loss resulting from cancer chemotherapy is particularly distressing. However, safe, effective therapies directed to hair have only just started to be developed. The hair follicle is a complex skin appendage composed of epidermal and dermal tissue, with specialized keratinocytes, the hair matrix cells, forming the hair shaft. Specific therapy of the hair follicle depends on selective targeting of specific cells of the hair follicle. We have developed the histoculture of intact hair-growing skin on sponge-gel matrices. We have recently found in histocultured skin that liposomes can selectively target hair follicles to deliver both small and large molecules. That liposomes can target the hair follicle for delivery has been confirmed independently. Two decades ago we introduced the technique of entrapping DNA in liposomes for use in gene therapy. In this report we describe the selective targeting of the lacZ reporter gene to the hair follicles in mice after topical application of the gene entrapped in liposomes. These results demonstrate that highly selective, safe gene therapy for the hair process is feasible.

New platinum complex compounds with reduced nephrotoxicity discovered in long-term histoculture of human renal cortical tissue

Cisplatinum is often effective in cancer treatment, but potent nephrotoxicity limits its clinical use. We have synthesized six new platinum compounds with the goal of reducing toxicity while maintaining efficacy. We initially tested drugs at 5 x 10(-4)M with 48 hours exposure in monolayer cultures of primary rabbit proximal tubular cells and human renal cortical cells with the MTT endpoint to measure toxicity. Drug concentration of 10(-3)M, 10(-4)M and 10(-5)M with 72 hours exposure were used for human renal cortical tissues in 7 week sponge-gel-supported histoculture with toxicity measured by the glucose-consumption endpoint. From these studies, we determined that the new platinum drugs have lower nephrotoxicity than cisplatinum.

"Seed" to "soil" is a return trip in metastasis

A critical aspect in understanding and treating cancer progression and metastasis is the relationship of the host originating organ and metastatic "soil" organs that support the growth and progression of the cancer "seed". We have recently demonstrated that there is a great difference in seemingly similar visceral organs, the colon and the stomach to support the growth progression of transplanted human colon tumors in nude mice. To further understand the relationship of seed and soil in cancer, we transplanted the metastatic human colon tumor CO-3 on the liver of nude mice, which is a usual metastatic soil organ for this tumor if transplanted to the nude-mouse colon. The intrahepatically-transplanted CO-3 tumor grew extensively on the nude-mouse liver without intra-hepatic metastasis. However, cecal growth, peritoneal dissemination, and invasiveness were noted after extensive growth on the liver with no spread to other organs. This phenomenon suggested that the intra-hepatically transplanted tumor could "reversibly metastasize" to the orthotopic site and secondarily spread into the abdominal cavity. The observation reported here suggests that "seed" to "soil" is reversible in metastasis in that the tumor can spread in either direction between two "matched" organ "soil".

Cancer seed and soil can be highly selective: human-patient colon tumor lung metastasis grows in nude mouse lung but not colon or subcutis

The question remains as to whether metastatic cells (cancer seed) that eventually colonize a particular organ (cancer soil) have specific properties that distinguish them from the other cells of the primary tumor. However until recently there have not been model systems in which this question could be fully answered. To further understand the relationship between seed and soil we have developed an orthotopic-transplantation nude-mouse model that allows human tumors to essentially replicate their behavior they had in the patient. The patient-like behavior of the transplanted human tumor in the nude mouse depends on the use of intact tumor tissue for orthotopic transplantation. Here we report that a colorectal tumor lung metastasis surgically resected from a patient could grow in nude mouse lung, but not in either the colon or the subcutis after transplantation of intact tissue. The results were striking in that the human colorectal tumor lung metastasis grew in the lung of the animals and not in the colon or in the subcutis of the animals. The results described here suggest that the lung metastasis of the patient colon tumor is distinct in its soil requirement from the majority of the cells of the original colon tumor. In contract, in the intact-tissue orthotopic transplant model, primary human colon tumors grow when transplanted to the colon of the nude mouse. Thus the colorectal cancer "seed" which metastasized to the lung in the patients seems very selective for the "soil" of the lung of both the patient and the nude mouse.

Human tumors are methionine dependent in vivo

Methionine-dependence is a tumor-specific biochemical defect expressed by the inability or decreased ability of tumors to grow under the condition of methionine-depletion. Many reports have shown that methionine-dependence occurs in human tumors of all types, including fresh surgical specimens in vitro. However, in vivo determinations of methionine-dependence have thus far been made only in rodent malignant tumors using methionine-deficient diets. We report here for the first time that human cancer xenografts in nude mice are methionine-dependent and when fed a methionine-free diet tumor growth is greatly inhibited. The body weight of mice on the methionine-free diet was found to be maintainable by once-per-week administration of methionine. The data presented here suggest that methionine-dependence can be an important target for human cancer treatment.

Clinical applications of the histoculture drug response assay

There is a need for a clinically useful drug-response assay for cancer patients to individualize their chemotherapy. Collagen sponge-gel-supported histoculture has been shown to maintain tissue architecture and function in vitro and has been utilized to develop the histoculture drug-response assay (HDRA) for individualizing chemotherapy. In order to evaluate the HDRA with the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide end point for clinical use, chemosensitivity to mitomycin C, doxorubicin, 5-fluorouracil, and cisplatin of 107 advanced gastric and 109 advanced colorectal cancers was determined in vitro in a correlative clinical trial. Two hundred eight (96.3%) of 216 of the patient specimens were evaluable in the HDRA. Thirty-eight patients with remaining measurable lesions after surgery were evaluable for comparison of the effects of chemotherapy in the HDRA with clinical outcome. Their overall response in the HDRA to all four drugs correlated to published historical data. Twenty-nine patients were treated with drugs shown to be ineffective in the HDRA, and all 29 cases showed clinical chemoresistance. In nine patients treated with drugs shown to be effective in the HDRA, six showed clinical chemoresponse and three showed arrest of disease progression. The correlation rate of the assay to clinical drug-sensitivity response was thus calculated to be 92.1% (35/38), with 100% (29/29) true-negative and 66.7% (6/9) true-positive rates, 100% (6/6) sensitivity, and 90.6% (29/32) specificity. Thirty-two patients with stage III and IV gastric cancer without remaining measurable tumor lesions after surgery were treated with mitomycin C and a fluoropyrimidine adjuvantly. The survival rate of 10 patients whose tumors were sensitive to either mitomycin C and/or 5-fluorouracil in the assay was significantly (P < 0.005) better than that of 22 patients whose tumors were shown to be insensitive to both drugs. Twenty-nine patients with stage III and IV colorectal cancer without remaining measurable tumor lesions after surgery were treated with fluoropyrimidines adjuvantly. The recurrence-free survival rate of 7 patients whose tumors were sensitive to 5-fluorouracil in the assay was significantly (P < 0.05) better than that of 22 patients whose tumors were insensitive. Thus the HDRA with the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide end point should be of clinical value to choose optimal chemotherapy for response as well as for survival.

Antioxidants and the prevention of coronary heart disease

Oxygen-free radical reactions have been implicated in many chronic disease processes, including atherosclerotic cardiovascular disease. Recent studies of lipid metabolism have suggested that oxidative modification of low-density lipoprotein accelerates atherogenesis. Micronutrient antioxidants, including alpha-tocopherol and beta-carotene, however, can neutralize oxygen-free radicals and inhibit low-density lipoprotein oxidation. This review examines (1) the role of oxidized low-density lipoprotein in atherogenesis, (2) the association between nutritional antioxidant intake and atherosclerosis, and (3) observational and clinical trial data on the effect of antioxidants in reducing the risk of coronary heart disease. While evidence suggests that antioxidant supplements protect against coronary heart disease, definitive recommendations await results from ongoing randomized trials of primary and secondary prevention.

Resolution of obstructive sleep apnea after microvascular brainstem decompression

Lesions of the brainstem have been associated with obstructive sleep apnea in previous reports. We now report a case in which retromastoid craniectomy with microvascular decompression of the medulla and ninth and tenth cranial nerves resulted in the complete resolution of severe obstructive sleep apnea. Possible mechanisms for this observation are discussed.

Host organ specifically determines cancer progression

In order to further understand the role of the host organ in tumor progression, we have transplanted into nude mice histologically intact human colon cancer tissue on the serosal layers of the stomach (heterotopic site) and the serosal layers of the colon (orthotopic site). Xenograft lines Co-3, which is well differentiated, and poorly differentiated COL-3-JCK were used for transplantation. After orthotopic transplantation of the human colon tumors on the nude mouse colon, the growing colon tumor resulted in macroscopically extensive invasive local growth in 4 of 10 mice, serosal spreading in 9 of 10 mice, musclaris propria invasion in 1 of 10 mice, submucosal invasion in 3 of 10 mice, mucosal invasion in 3 of 10 mice, lymphatic duct invasion in 4 of 10 mice, regional lymph node metastasis in 4 of 10 mice, and liver metastasis in 1 of 10 mice. In striking contrast, after heterotopic transplantation of the human colon tumor on the nude mouse stomach, a large growing tumor resulted but with only limited invasive growth and without serosal spreading, lymphatic duct invasion, or regional lymph node metastasis. It has become clear from these studies that the orthotopic site, in particular the serosal and subserosal transplant surface, is critical to the growth, spread, and invasive and metastatic capability of the implanted colon tumor in nude mice. These studies suggest that the original host organ plays the same critical role in tumor progression.

In vivo and in vitro effects of androgen on fibroblast growth factor-2 concentrations in the human prostate

Prostatic growth is primarily regulated by dihydrotestosterone (DHT). Recent studies have demonstrated that a large number of growth factors are present in the human benign prostatic hyperplasia (BPH) prostate, including epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), transforming growth factor beta (TGF-beta), insulin-like growth factor (IGF), and basic fibroblast growth factor (bFGF) (FGF-2). DHT may mediate its mitogenic effects in the prostate by regulating growth factors. To test this hypothesis, we have utilized a histoculture androgen sensitivity assay (HASA) in which 3H-thymidine incorporation is measured in aliquots of BPH tissue in histoculture with either added DHT or hydroxyflutamide (HF). The resulting DHT/HF ratio is an expression of the androgen sensitivity of the tissue. In this study, we have compared the DHT/HF ratio for 3H-thymidine incorporation to the DHT/HF ratio for FGF-2 measured in the histocultured prostates. The DHT/HF ratio for the HASA studies of 3H-thymidine incorporation averaged 2.68 compared to the DHT/HF ratio for FGF-2 in the same specimens of 1.01. These values were significantly different, therefore indicating no relationship between DHT stimulation and FGF-2 levels. In addition, FGF-2 levels were measured in human BPH prostates from patients medically castrated with megesterol acetate and estradiol 17-beta prior to surgery. These values were not significantly different, and therefore do not suggest any effect of DHT on the concentration of prostatic FGF-2. Although these studies did not show any effect of DHT on the regulation of prostatic FGF-2, they do indicate that the HASA assay is feasible and appropriate to use in the study of relationships between DHT and various growth factors.

Therapeutic trials for low back pain

Little consensus exists regarding the indications for and effectiveness of many back pain treatments. This clinical uncertainty arises because most back pain research has been flawed by poor methodology. The authors discuss strategies for improving the quality of back pain research on treatment efficacy. Design features, including randomized treatment allocation, independent outcome assessors, comprehensive outcome measures, appropriate statistical analyses, and close patient follow-up can increase study validity. Complete descriptions of enrollment criteria, patient characteristics, and clinical interventions can increase the generalizability of results. Although large scale trials often involve university centers, community-based researchers can collaborate on randomized trials or conduct valuable cohort studies.

"Patient-like" nude mouse metastatic model of advanced human pleural cancer

Pleural cancer in humans is a frequently occurring tumor. Recently, clinical trials have suggested that chemotherapy and immunotherapy administered intrapleurally may elicit responses in early-stage diseases. However, at radiological and pleural endoscopic evaluation, most of the patients are found to have a visceral pleural involvement that is generally refractory to therapy and leads to a poor prognosis. The goal of this study was to construct a nude mouse model of human parietal- and visceral-pleural cancer that could reflect the clinical picture for this disease. The model could then be useful for drug discovery for pleural cancer. A well-differentiated human lung adenocarcinoma was used as intact tissue for implantation. Ten mice underwent parietal-pleural implantation and ten mice visceral-pleural implantation via a novel thoracotomy procedure we have developed. Symptoms of tumor growth were determined from weight loss, respiratory distress, or debilitation. Actual tumor growth and spread were measured at autopsy. The mouse survival curves of each group were estimated by the Kaplan-Meier method and the difference of the median survival times was assessed by the Log-rank test. The slopes of mean-mouse weight curves were compared using a standard two-sample t-test. A 100% take rate was achieved in constructing the pleural cancer models. Tumor growth was initially assessed by symptomatology and survival: the median survival time was, respectively, 27.9 days and 31 days for visceral-pleural and parietal-pleural implanted groups (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Matrix metalloproteinase inhibitor BB-94 (batimastat) inhibits human colon tumor growth and spread in a patient-like orthotopic model in nude mice

Matrix metalloproteinases have been implicated in the growth and spread of metastatic tumors. This role was investigated in an orthotopic transplant model of human colon cancer in nude mice using the matrix metalloproteinase inhibitor BB-94 (batimastat). Fragments of human colon carcinoma (1-1.5 mm) were surgically implanted orthotopically on the colon in 40 athymic nu/nu mice. Administration of BB-94 or vehicle (phosphate buffered saline, pH 7.4, containing 0.01% Tween 80) commenced 7 days after tumor implantation (20 animals/group). Animals received 30 mg/kg BB-94 i.p. once daily for the first 60 days and then 3 times weekly. Treatment with BB-94 caused a reduction in the median weight of the primary tumor from 293 mg in the control group to 144 mg in the BB-94 treated group (P < 0.001). BB-94 treatment also reduced the incidence of local and regional invasion, from 12 of 18 mice in the control group (67%) to 7 of 20 mice in the treated group (35%). Six mice in the control group were also found to have metastases in the liver, lung, peritoneum, abdominal wall, or local lymph nodes. Only two mice in the BB-94 group had evidence of metastatic disease, in both cases confined to the abdominal wall. The reduction in tumor progression observed in the BB-94-treated group translated into an improvement in the survival of this group, from a median survival time of 110 days in the control group to a median survival time of 140 days in the treated group (P < 0.01). Treatment with BB-94 was not associated with any obvious toxic effect, and these results suggest that such agents may be effective as adjunctive cancer therapies.

Correlation of proteolytic activities of organ cultured intact mouse skin with defined hair cycle stages

The cyclic growth activity of the hair follicle is characterized by substantial remodelling of the extracellular matrix, yet, little is known about the proteolytic activities regulating this process. In murine skin, hair cycling is highly synchronized and is associated with dramatic remodeling of all skin compartments. We therefore have assessed, in this pilot study, proteolytic activities of murine skin from various stages of the depilation-induced hair cycle. We show that the defined proteolytic activities displayed by organ cultured intact mouse skin differ between hair cycle stages. Skin with all follicles in telogen or mid anagen displayed only minimal lysis of collagen type I gels, while early anagen skin had significant collagenase activity. Skin cultured on gelatin gels at the air-liquid interphase ('histoculture') completely lysed the gel within 5 days when all follicles were in early anagen, while this was not observed with mid and very late-anagen skin. Zymography of conditioned medium from these cultures revealed the secretion of activated interstitial collagenase and of gelatinases of 72 and 92 kDa, with the maximum of interstitial collagenase activity secreted by anagen IV skin. Addition of TPA or TNF-alpha to the culture medium stimulated secreted collagenase type I activity. The C 57 BL-6 mouse offers an attractive model for dissecting and manipulating hair cycle-associated proteolysis in a physiologically relevant system.

The three-dimensional question: can clinically relevant tumor drug resistance be measured in vitro?

In vivo-like drug responses are observed in three-dimensional culture but frequently not in two-dimensional culture, indicating that drug response may be a function of tissue architecture. Alexis Carrel introduced that in vitro culture of tissues in the beginning of the century utilizing a culture system that allowed the three-dimensional growth of tissues. Leighton improved upon this system by developing a substrate of sponge matrices. Other methods of three-dimensional culture include collagen gels and what are known as organ culture systems on filters or meshes. In addition, cell suspensions can be converted into multicellular spheroids, another form of three-dimensional culture. Comparison of the three-dimensional culture methods with two-dimensional culture methods has shown critical differences in drug response. The in vivo mechanism of drug resistance may involve alterations in cell-cell interaction which may occur in three-dimensional culture as opposed to monolayer culture.

Recombinant human interferon alpha-2a increases 5-fluorouracil efficacy by elevating fluorouridine concentration in tumor tissue

The modulating effect of recombinant human interferon alpha (IFN-alpha) on the antitumor efficacy of 5-fluorouracil (5-FU) against human carcinoma cell lines was investigated in vitro and in vivo. 5-FU, fluorouridine (FUR) or fluoro-5'-deoxyuridine (FUdR) were tested against cultured human colon tumor C-1 cells with or without IFN-alpha. The in vitro antitumor activity of 5-FU was enhanced by the addition of IFN-alpha, but IFN-alpha did not increase the effect of FUR or FUdR. The in vivo antitumor activity of 5-FU with or without IFN-alpha was assessed using Co-4, a human colon carcinoma xenograft, in nude mice. Thymidylate synthetase inhibition and concentration of FUR in the treated tumor tissues were concomitantly measured. A synergistic effect of 5-FU and IFN-alpha was observed on Co-4 in nude mice, and this in vivo synergism was obtained without any increment of thymidylate synthetase inhibition or side effects in terms of death rate and body weight loss. The intratumoral concentration of FUR was significantly increased by the addition of IFN-alpha in Co-4 tumor tissue treated with 5-FU. These results suggest that the mechanism of the combined effect of 5-FU and IFN-alpha is not related to enhancement of thymidylate synthetase inhibition, but to an increase of FUR concentration in the target tumor tissue. It is expected that this combination method will be clinically useful for the treatment of advanced colorectal carcinoma.

Antitumor activity of (2''R)-4'-O-tetrahydropyranyl adriamycin on human gastric cancer cell lines in vitro and in vivo

The antitumor activity of (2''R)-4'-O-tetrahydropyranyl adriamycin (pirarubicin; THP) was assessed using human gastric cancer cell lines in vitro and in vivo. The cytotoxicity of THP on MKN-28 and MKN-45 was superior to that of adriamycin (ADM) as detected by a growth assay with an MTT colorimetric endpoint. When the same doses of THP and ADM were administered intraperitoneally to nude mice bearing St-15, St-40 and SC-1-NU, the antitumor activity of THP was almost equivalent to ADM in terms of relative mean tumor weight. However, the adverse effects of THP were also significantly lower than those of ADM in terms of death rate, body weight loss and spleen weight loss. This was also confirmed in THP or ADM combination chemotherapy with mitomycin C and 5-fluorouracil on St-15 and MKN-45. These results indicated that THP is a candidate anthracycline to replace ADM for combination cancer chemotherapy in gastric carcinoma.

Combined effect of 5-fluorouracil and carboplatin against human gastric cancer cell lines in vitro and in vivo

The antitumor activity of a sequential combination of 5-fluorouracil (5-FU) and carboplatin (JM-8) was evaluated using gastric cancer cell lines in vitro and in vivo. In the in vitro study, the sequence of 5-FU followed by JM-8 showed higher antitumor activity than that of the reverse sequence. The sequence of 5-FU at 5 micrograms/ml for 24 h followed by 5 micrograms/ml JM-8 for 24 h showed antitumor activity almost equivalent to that of 10 micrograms/ml 5-FU for 24 h and higher activity than that of 10 micrograms/ml JM-8 for 24 h on two cell lines. To evaluate the antitumor activity and toxicity of 5-FU and JM-8 in vivo, BALB/cA nu/nu mice bearing human gastric cancer xenografts St-15, St-40 and SC-1-NU were administered 5-FU and JM-8 intraperitoneally. The sequence of 5-FU prior to JM-8 showed higher antitumor activity than that of the reverse sequence on all the xenografts, and simultaneous administration of 5-FU and JM-8 showed the most potent antitumor activity on St-40 and SC-1-NU. On the other hand, the sequence of 5-FU before JM-8 showed the lowest toxicity in all the treated groups, in terms of death rate, body weight loss and spleen weight loss. This combination is thought to be a promising chemotherapy regimen, showing high antitumor activity without an increment of toxicity.

Sponge-gel-supported histoculture drug-response assay for head and neck cancer. Correlations with clinical response to cisplatin

OBJECTIVE

Sponge-gel-supported histoculture drug-response assay (SSHDRA) represents a promising method to determine chemosensitivity of solid tumors. To determine whether the assay correlates clinically, we compared the in vivo and in vitro effects of cisplatin in 23 of 26 patients with head and neck cancers.

DESIGN

The criterion for in vitro sensitivity to cisplatin was an 84% or greater inhibition by cisplatin of the number of tritiated thymidine-incorporating cells of the histocultured tumors compared with untreated control culture preparations, as measured by means of histologic autoradiography. Comparisons were made with clinical responses, ie, complete response, partial response, or no response.

PATIENTS

The study was carried out in patients with head and neck cancers and comprised 21 patients with squamous-cell carcinoma, three patients with other carcinomas, and two patients with sarcoma.

RESULTS

Ten of 12 patients with in vitro-sensitive tumors had either complete or partial response clinically. The overall accuracy of the SSHDRA was 74% in this correlative clinical trial; the predictive-positive value was 83%, the sensitivity was 71%, and the specificity was 78%. Seven of 11 patients with in vitro-resistant tumors demonstrated no response for a predictive-negative value of 64%.

CONCLUSIONS

We conclude that the SSHDRA shows a high correlation for tumors that demonstrate both in vivo drug resistance and sensitivity. The in vitro-like maintenance of three-dimensional tissue architecture of the tumors in histoculture probably contributes to high clinical predictivity of drug response of the SSHDRA. The data support further comparisons to determine the clinical usefulness of the SSHDRA for identifying complete and partial responders to chemotherapy.

Modifiable risk factors for incident heart failure in the coronary artery surgery study

BACKGROUND

Even with aggressive treatment, heart failure is associated with a substantial morbidity and mortality. This poor prognosis has led to increasing interest in primary prevention, and the identification of modifiable risk factors. Our objective was to determine whether modifiable cardiovascular risk factors, including systolic and diastolic blood pressure, fasting glucose level, cholesterol level, weight, and smoking, were independent risk factors for heart failure in patients with anatomically confirmed coronary artery disease.

METHODS

We studied all patients with documented coronary artery disease eligible for the multicenter, randomized-controlled Coronary Artery Surgery Study. After excluding 79 prevalent cases, we identified incident cases of heart failure using hospital discharge abstracts, mortality records, or self-reported follow-up questionnaires. Criteria for self-reported cases were treatment with digitalis and/or furosemide plus two or more heart failure symptoms, including dyspnea on exertion, orthopnea, paroxysmal nocturnal dyspnea, or edema. Cox regression analysis was used to estimate adjusted relative risks.

RESULTS

At 12-year follow-up, the cumulative incidence of heart failure was 20.6%. Smoking (relative risk, 1.47) and weight (relative risk, 1.15/10 kg) were independently associated with incident heart failure. Myocardial infarction during follow-up, age, female sex, and baseline left ventricular dysfunction were also risk factors for heart failure.

CONCLUSIONS

Patients with stable coronary artery disease are at high risk for developing heart failure, especially following myocardial infarction. However, interventions aimed at smoking cessation and weight reduction may prevent clinical heart failure in these patients.

Comparison of glucose-consumption and thymidine-incorporation endpoints in histocultured human superficial bladder tumors

Glucose consumption and tritiated thymidine incorporation were monitored for 54 days in histocultured human superficial transitional cell carcinoma of the bladder, indicating that long-term histoculture of human transitional cell carcinoma of the bladder is feasible. The glucose-consumption rate was relatively similar among the histocultured specimens and depended on the size of the explant in histoculture. Tritiated thymidine incorporation, on the other hand, varied greatly between the histocultured specimens. In addition, [3H]thymidine incorporation varied in single histocultures between cells in the original explant and those invading the gel. From these results, we conclude that the glucose consumption rate in histocultured human superficial bladder tumor is more reliable and sensitive than thymidine incorporation. The glucose-consumption endpoint is simple to measure and nondestructive, allowing multiple measurements on a single culture, unlike the thymidine incorporation endpoint.

A "patient-like" nude mouse model of parietal pleural human lung adenocarcinoma

Histologically intact human adenocarcinoma of the lung maintained in nude mice by serial subcutaneous transplantations (4 generations) was harvested and transplanted to the parietal pleura of 11 other nude mice via a novel thoracotomy procedure. Local and regional tumor growth of transplanted tumors occurred in all cases within 31 days, resulting in weight loss, decreased physical activity and death. This rapid-growth "patient-like" model of direct transplantation of a human neoplasm to the parietal pleura may facilitate basic research of pleural malignancies, and stimulate studies of pleural tumor response to cytotoxic treatment, biologic modifiers, and other modalities of treatment. and other modalities of treatment.

Therapeutic tumor-specific cell cycle block induced by methionine starvation in vivo

The ability to induce a specific cell cycle block selectively in the tumor could have many uses in chemotherapy. In the present study we have achieved this goal of inducing a tumor-specific cell cycle block in vivo by depriving Yoshida sarcoma-bearing nude mice of dietary methionine. Further, we demonstrate that methionine depletion also causes the tumor to eventually regress. The antitumor effect of methionine depletion resulted in the extended survival of the tumor-bearing mice. The mice on the methionine-deprived diets maintained their body weight for the time period studied, indicating that tumor regression was not a function of body weight loss. The data reported here support future experiments utilizing methionine depletion as a target for tumor-selective cell cycle-dependent therapy.

The preparation of endotoxin-free L-methionine-alpha-deamino-gamma-mercaptomethane-lyase (L-methioninase) from Pseudomonas putida

Many types of human and animal tumors have an absolute requirement for methionine. This requirement can be satisfied by homocysteine only in normal cells and tissues. Therefore, methionine may be an important target in cancer therapy. To attack this target we have purified endotoxin-free methioninase from Pseudomonas putida by a novel and simple procedure. This procedure involves (1) a heat step of the cell extract at 60 degrees C for 8 min, (2) DEAE-Toyopearl ion-exchange chromatography, (3) DEAE-Sephadex A50 ion-exchange gel filtration chromatography, and (4) affinity chromatography on Acticlean to remove the endotoxin bound to the enzyme. The yield for this purification was up to 80%. The methioninase has four subunits of approximate molecular weight 43 kDa. This is the first methodology for methioninase that allows rapid purification with high yield and separation from endotoxin suitable for in vivo efficacy testing against methionine-dependent tumors in animal models.

Metastatic human pleural ovarian cancer model constructed by orthotopic implantation of fresh histologically-intact patient carcinoma in nude mice

Pleural cancer is a frequently-occurring tumor that is generally refractory to therapy. Clinically-relevant animal models of human pleural cancer are greatly needed for testing experimental and standard treatments, as well as for understanding the clinical features of this disease. We report the first orthotopic transplant model for human patient pleural cancer. Fresh histologically-intact patient specimens of human pleural ovarian adenocarcinoma were implanted onto the visceral and parietal pleura of nude mouse. The human tumors grew locally and regionally mimicking the usual human clinical features of this disease. Moreover, only visceral pleural implantation subsequently involved mediastinal lymph nodes corroborating clinical observations suggesting that visceral pleural involvement in pleural cancer represents an advanced-stage disease. This model should facilitate basic research of pleural malignancies, and stimulate studies of pleural-tumor response to cytotoxic treatment, biologic modifiers, and other modalities of therapy.

Depletion of serum methionine by methioninase in mice

Methionine dependence is a tumor-specific metabolic defect found in human cancer cell lines as well as in fresh human tumor specimens. Methionine dependent tumors cease growing when deprived of methionine, unlike normal cells which can substitute homocysteine for methionine for their growth requirement. We have previously purified a stable, endotoxin-free methioninase from the bacterium, Pseudomonas putida. We demonstrate in this report that purified methioninase can lower the serum levels of methionine in normal and nude mice from 60 microM to approximately 5 microM within 1 hour. The circulating half-life of methioninase is approximately 100 minutes in mice after i.v. injection. The enzyme therefore seems to be a good candidate as an antitumor agent for methionine-dependent tumors.

The measurement of glucose consumption in histoculture to determine effects of doxorubicin and cisplatinum on human gastric carcinoma

We have developed a chemosensitivity assay of human tumors growing on collagen-sponge-gel-supported histoculture. This assay is thus termed the Histoculture Drug Response Assay (HDRA). In the HDRA, the end points of [3H]thymidine incorporation measured by histological autoradiography and tetrazolium dye reduction were initially used and found to have good in vitro-in vivo correlations, including that determined in clinical trials. We have now developed glucose consumption as an endpoint in histoculture. We have monitored glucose consumption for 11 weeks with histocultured stomach cancer tissue that was obtained from a patient with stomach cancer metastatic to the lymph node. The histocultured lymph node specimens were treated with various concentrations of doxorubicin and cisplatinum. The glucose-consumption rate decreased with greater concentrations of both drugs. The results correlated with the thymidine labeling index. From these results, we conclude that the glucose-consumption-rate endpoint in histocultured cancer tissue is non-destructive, unlike the [3H]thymidine and tetrazolium dye end points, allowing serial determinations over extended periods in culture. Thus, the glucose consumption end point may enhance the development of optimal treatment doses and schedules. We also conclude that long-term histoculture drug response studies of metastatic stomach cancer are possible.

Similarity of serum-tumor pharmacokinetics of antitumor agents in man and nude mice

A pharmacokinetic comparison was made between nude mice and human gastric cancer patients. This comparison is important in order to optimize the human tumor xenograft-nude mouse system as a screening panel for potential antitumor agents. In this report, mitomycin C (MMC), doxorubicin (DXR), 5-fluorouracil (5-FU) and cisplatin (DDP) were administered to nude mice bearing human tumor subcutaneous xenografts in maximum tolerated doses and to patients with gastric cancer at conventional doses. The concentrations of antitumor agents in serum and tumor were detected by bioassay for MMC and 5-FU, by high performance liquid chromatography for DXR, and by atomic absorption method for DDP. Peak drug concentrations in the serum (Cmax) the mice and humans correlated well with statistical significance (R = 0.999, P < 0.0001). When Cmax and drug concentrations in the tumor (T) the mice and human were compared with each other to evaluate the uptake of drugs into the tumor from the serum and calculated as T/Cmax, similar results were observed for the same agent with statistical significance (r = 0.990, p < 0.02). These results indicate that the human tumor xenograft-nude mouse system and humans are essentially similar pharmacodynamically, which further validates the uses of this system to evaluate potential antitumor agents.

Surgery for herniated lumbar discs: a literature synthesis

OBJECTIVE

To assess the risks and benefits of surgery for herniated lumbar discs (discectomy) and to evaluate the methodologic quality of the literature.

DESIGN

Literature synthesis. STUDY SELECTION AND DATA ANALYSIS: A structured MEDLINE search identified studies of standard, microsurgical, or percutaneous discectomy. Eligible studies had adult subjects, sample sizes of > or = 30, clinical outcome data for > or = 75% of patients, and follow-up of > or = 1 year. Summary rates of successful outcomes, reoperations, and complications were obtained by a random-effects logistic regression model. Methodologic quality was assessed using established study design criteria.

RESULTS

Eighty-one studies met inclusion criteria. Most had substantial design flaws and/or omitted important clinical data. Randomized trials of standard discectomy showed better short-term sciatica relief following surgery; 65% to 85% of patients reported no sciatica one year after surgery, compared with only 36% of conservatively treated patients. No data from randomized trials were available for microdiscectomy or percutaneous discectomy, although most outcomes appeared comparable to those of standard discectomy. Approximately 10% of discectomy patients underwent further back surgery, and rates increased over time. The rate of serious complications, including death and permanent neurologic damage, was less than 1%.

CONCLUSIONS

Most studies were poorly designed and reported. Standard discectomy appears to offer better short-term outcomes than does conservative treatment, but long-term outcomes are similar. Discectomies are relatively safe procedures, though reoperations are common and increase over time. Decisions for elective surgery must balance faster pain relief against the risks and costs of surgery.

A novel "patient-like" treatment model of human pancreatic cancer constructed using orthotopic transplantation of histologically intact human tumor tissue in nude mice

Pancreatic cancer is a disease with essentially no effective treatment. To increase the potential for discovering effective treatment, we have developed a new treatment model whereby a human pancreatic cancer line, PANC-4, was orthotopically transplanted to the pancreas of nude mice as histologically intact tumor tissue. The tumor grew with subsequent invasive local tumor growth and liver and peritoneal metastases. The antitumor activity of 5-fluorouracil (5-FU) and mitomycin C (MMC) against PANC-4 was initially determined in the in vitro collagen-sponge-gel supported histoculture drug-response assay with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide end point. Inhibition rates were 5.6% for 5-FU and 39.4% for MMC indicating higher efficacy of MMC than 5-FU against PANC-4. When the antitumor activities of 5-FU and MMC against PANC-4 were determined in vivo using the nude mouse orthotopic transplant treatment model, slight local tumor growth inhibition with equivalent incidence of metastases to the liver and the peritoneum as the control were observed in the mice treated with 5-FU, while those treated with MMC had considerably reduced local tumor growth without liver and peritoneal metastases. Thus the histoculture drug-response assay in combination with the orthotopic transplant metastatic models provides for the first time a paradigm for evaluation of agents which may be effective against not only locally growing human pancreatic cancer but resulting metastases as well.

A metastatic orthotopic-transplant nude-mouse model of human patient breast cancer

We report here the development of an orthotopic-transplant model of human patient breast cancer in nude mice. Histologically-intact patient breast tumor tissue was transplanted as intact tissue to the mammary fat pad of nude mice where the tumor tissue grew extensively and metastasized to the lung. This is the first orthotopic-transplant metastatic model of human breast cancer. The potential clinical and basic-science uses of the model are discussed.

Mode of action of estra-1,3,5(10)-triene-3, 17 beta-diol, 3-benzoate, 17[4-[4-[bis(2-chloroethyl)amino]phenyl]-1-oxobutoxy] acetate] (KM2210) on MCF-7 human breast tumours transplanted into nude mice

KM2210 is a benzoate of an estradiol-chlorambucil conjugate with three active metabolites, KM2202, estradiol (E2) and chlorambucil (CBL). The mode of action of this compound was assessed using MCF-7 human breast tumours transplanted into nude mice. The growth of MCF-7 in nude mice was inhibited by KM2210 and enhanced by E2, although the serum levels of E2 in nude mice treated with KM2210 and E2 were similar. The antitumour activity of CBL was completely blocked by extrinsic E2, while KM2210 suppressed the growth of MCF-7 in spite of the presence of E2 in the serum of tumour-bearing nude mice. KM2210 and KM2202 suppressed the expression of cytosol estrogen receptor (ER) of MCF-7 cells detected by the dextran-coated charcoal and fluorescent E2 staining method, although CBL did not affect the ER expression of MCF-7 cells. This inhibitory effect of KM2210 on ER was also corroborated by the fact that the pretreatment with KM2210 prevented the E2-stimulated growth of MCF-7 in nude mice. These results indicated that one of the effects induced by KM2210 is the blockage of ER expression in combination with the alkylating antitumour activity of CBL. KM2210 is thought to be a promising agent with unique modes of action for ER-positive breast carcinomas.

Lack of influence of c-Ha-ras expression on the drug sensitivity of human bladder cancer histocultured in three-dimensions

The mechanism of drug resistance in human cancers is complex. In addition to overexpression of a series of multiple-drug-resistance genes, there has been the suggestion that the Ha-ras gene may participate in conferring resistance. In this study, a series of three human-bladder carcinoma cell lines were studied, one parental type, one transfected by wild-type Ha-ras and another transfected by mutant Ha-ras. The ras gene was overexpressed in the latter two cell lines which also were more invasive than the parental when injected as individual cells in the nude-mouse bladder. The results described here have indicated that the ras-gene expression level or mutational status did not affect drug resistance when the tumor lines were histocultured as three-dimensional tissue on collagen-sponge-gels. The drug-response spectrum of the histocultured lines qualitatively reflected a clinical experience although all lines were relatively drug resistant, possibly reflecting their three-dimensional configuration in culture.

Expression of the biochemical defect of methionine dependence in fresh patient tumors in primary histoculture

Methionine dependence is a metabolic defect that occurs in many human tumor cell lines but not normal in unestablished cell strains. Methionine-dependent tumor cell lines are unable to proliferate and arrest in the late S/G2 phase of the cell cycle when methionine is replaced by its immediate precursor homocysteine in the culture medium (MET-HCY+ medium). However, it is not known whether methionine dependence occurs in fresh patient tumors as it does in cell lines. In order to determine whether methionine dependence occurs in fresh patient tumors as well as whether methionine dependence occurs in fresh patient tumors as well as in cell lines we took advantage of the technique of sponge-gel-supported histoculture to grow tumors directly from surgery. We then measured nuclear DNA content by image analysis to determine the cell cycle position in MET-HCY+ compared to MET+HCY- medium in 21 human patient tumors. Human tumor cell lines found to be methionine dependent by cell count were used as positive controls and were found to have marked reduction of cells in G1 compared to total cells in the cell cycle in MET-HCY+ medium with respect to the G1: total cell ratio in MET+HCY- medium. Therefore late cell cycle arrest was used as a marker of methionine dependence for histocultured patient tumors. We found that 5 human tumors of 21, including tumors of the colon, breast, ovary, prostate, and a melanoma, were methionine dependent based on cell cycle analysis. These data on fresh human tumors indicate that methionine dependence may frequently occur in the cancer patient population. Implications for potential therapy based on methionine dependence are discussed.

Differential chemosensitivity of local and metastatic human gastric cancer after orthotopic transplantation of histologically intact tumor tissue in nude mice

We have established a metastatic model of human gastric cancer using orthotopic transplantation of histologically intact tissue in nude mice, and have used this model to evaluate the effects of immunochemotherapy using OK-432, 5-fluorouracil (5-FU) and mitomycin C (MMC) against SC-I-NU, a human stomach cancer line. One-quarter or one-half maximum tolerated doses (MTDs) of 5-FU or MMC resulted in a significant reduction of stomach tumor growth, while liver metastases were not reduced, possibly due to suppression of natural killer (NK)-cell activity by both drugs. On the other hand, when combined with OK-432, half MTDs of 5-FU and MMC significantly reduced liver metastases, with synergistic reduction of stomach tumor growth, possibly reflecting a rescue of NK-cell activity by treatment with OK-432. This metastatic model of human stomach cancer shows that locally growing and metastatic tumors may have different chemosensitivities, and provides the opportunity to test both with various treatment regimens.

Site-specific chemosensitivity of human small-cell lung carcinoma growing orthotopically compared to subcutaneously in SCID mice: the importance of orthotopic models to obtain relevant drug evaluation data

We have developed a novel in vivo model of human small-cell lung carcinoma (SCLC) using orthotopic reconstitution by injecting human SCLC in the tail vein of severe combined immunodeficient (SCID) mice whereby the SCLC grows in the lung and other organs. Cisplatin (DDP) had significant antitumor effects on the SCLC growing orthotopically in the lung whereas mitomycin C (MMC) did not, thereby reflecting the clinical situation. However, the opposite effects were found when the SCLC was growing subcutaneously, where the tumors responded to MMC and not to DDP. This suggests that the tumors growing orthotopically reflect the clinical effects of drugs on human SCLC more closely than the tumors growing subcutaneously. Therefore, this orthotopic reconstitution model of human SCLC in SCID mice is thought to be useful for studies on the treatment of human SCLC and emphasizes the need for orthotopic models for relevant cancer drug evaluation.

To do tissue culture in two or three dimensions? That is the question

Alexis Carrel introduced the in vitro culture of tissues in the beginning of the century utilizing a culture system that allowed the three-dimensional growth of tissues. Leighton improved upon this system by developing a substrate of sponge matrices. Other methods of three-dimensional culture include collagen gels and what are known as organ culture systems on filters or meshes. In addition, cell suspensions can be converted into multicellular spheroids, another form of three-dimensional culture. Comparison of the three-dimensional culture methods with two-dimensional culture methods has shown critical differences in the behavior of biological systems in culture. For example, in vivo-like drug responses are observed in three-dimensional but frequently not in two-dimensional cultures, indicating that drug response may be a function of tissue architecture. The in vivo mechanism of drug resistance may involve alterations in cell-cell interaction which may occur in three-dimensional culture as opposed to monolayer culture. Practical applications of three-dimensional culture include the development of a drug-response assay that correlates not only with drug resistance but also with drug sensitivity and survival of cancer patients. It has been shown that gene expression may be more in vivo-like in three-dimensional cultures than in two-dimensional monolayer cultures. For example, tumor antigens may be expressed in three-dimensional culture and not in monolayer culture. Thus, future studies utilizing three-dimensional cultures may significantly enhance our understanding of gene expression and resistance to drugs and enhance the efficacy of cancer chemotherapy by correctly predicting active drug regimens for individual patients.

Nude mouse metastatic models of human stomach cancer constructed using orthotopic implantation of histologically intact tissue

Nude mice have been used to develop s.c. growing human stomach tumors, but these rarely metastasize. Recently, I. J. Fidler and others have developed orthotopic implantation metastatic models using cell suspensions which are inoculated into the corresponding organ of nude mice from which the tumor cells were originally derived in the human. However, recent work has indicated that disaggregated cell suspensions may not always express their full metastatic potential. In this light, we have recently developed an orthotopic implant model utilizing intact tissue such as that obtained directly from surgery. This approach has yielded high take rates and frequent metastases in colon cancer, bladder cancer, lung cancer, pancreatic cancer, and prostate cancer. We report here the application of this intact tissue orthotopic implant technique to stomach cancer resulting in the formation of metastases in 100% of the mice with extensive primary growth to the regional lymph nodes, liver, and lung. In contrast, when cell suspensions were used to inject stomach cancer cells at the same site, metastases occurred in only 6.7% of the mice with local tumor formation, emphasizing the importance of using intact tissue to allow full expression of metastatic potential. Injuring the serosa similar to that occurring in intact tissue transplantation did not increase the metastatic rate after orthotopic injection of cell suspensions of stomach tumor cells. This intact tissue orthotopic implantation model should allow development of new treatment modalities and further study of the biology of human stomach cancer.

Human ovarian carcinoma metastatic models constructed in nude mice by orthotopic transplantation of histologically-intact patient specimens

We report here the first orthotopic transplant model for human ovarian cancer. Histologically-intact patient specimens of ovarian cancer were transplanted by microsurgical techniques under the capsule of the nude mouse ovary. The human tumors grew locally and gave rise to a patient-like metastatic pattern including the parietal peritoneum, colon, omentum, and ascites. The orthotopic model described here should be useful for evaluating new therapeutics and diagnostics for ovarian cancer.

Early resection of primary orthotopically-growing human colon tumor in nude mouse prevents liver metastasis: further evidence for patient-like hematogenous metastatic route

We have developed an orthotopic transplant model of human cancer to immunodeficient mice utilizing microsurgical techniques with intact tissue. The resulting transplanted human tumors grow locally and metastasize in a clinical-like pattern. However, there has been no definitive evidence in colon cancer that the human tumors metastasize via hematogenous route in nude mice. In the present study, in order to obtain definitive evidence of physiological spread of the human tumors, the primary tumors were resected 10 days after the initial orthotopic transplantation to the nude mice. The resection prevented metastases from forming, demonstrating that metastases of the human colon cancers occur after 10 days and by physiological and non-seeding mechanisms in the transplanted nude mice.