Ubiquitin fusion proteins are overexpressed in colon cancer but not in gastric cancer

A cDNA clone (AF3) encoding the ubiquitin A gene 52 amino acid extension fusion protein (UbA52) was isolated from a subtracted cDNA library of human colorectal carcinoma minus adjacent normal mucosa. In Northern hybridization the mRNA signal for UbA52 was greater in surgical samples of colonic carcinoma (T) than in paired adjacent normal (N) tissues in 24 of 29 cases (T/N = 3.4 +/- 0.5, P < 0.01). An oligonucleotide probe specific for only the 52 amino acid extension confirmed the overexpression of UbA52. In contrast, there was no overexpression of UbA52 mRNA in gastric cancer samples (n = 7, T/N = 1.0 +/- 0.3). The mRNA of several ribosomal proteins, and of another ubiquitin A gene fusion protein, UbA80, with an 80 amino acid extension of ribosomal protein S27a, have been reported to be over-expressed in colon cancer, but not as yet at the protein level. Using rabbit antisera to the ribosomal protein component S27a we demonstrate over-expression of S27a at the protein level in colonic (n = 5), but not gastric (n = 6) carcinomas. Therefore it is likely that both UbA80 and UbA52 are overexpressed in colon cancer, but not in gastric cancer.

State of the defunctionalized sphincter in patients undergoing ileoanal pouch anastomosis

PURPOSE

Our aim was to determine manometric status and functional outcome of the ileoanal pouch procedure in a subset of patients with defunctionalized anal sphincters as a result of long-term fecal diversion.

METHODS

The anal manometric profiles of 12 patients defunctionalized for one year or more were compared with 26 patients with nondefunctionalized anal sphincters. Functional data were obtained from the Lahey Clinic Ileoanal Pouch Registry.

RESULTS

Preoperative manometric data revealed a mean resting pressure of 91.5 mmHg in the nondefunctionalized group vs. 68.7 mmHg in the defunctionalized group; mean squeezing pressure was 171.7 mmHg (nondefunctionalized group) vs. 102.3 mmHg (defunctionalized group); and squeezing pressure volume was 1,283,000 mmHg3 (nondefunctionalized group) vs. 585,000 mmHg3 (defunctionalized group). Functionally both groups had a mean of 6.1 bowel movements in a 24-hour period and could defer defecation for a mean of 2 hours. Leakage occurred in 22 percent of the defunctionalized group and 17 percent of the nondefunctionalized group (P = 0.35).

CONCLUSION

Despite physiologic perturbations, the long-term, defunctionalized anal sphincter can adequately support a restorative procedure without regard to timing of pouch creation.

Computer-generated profiles of the anal canal in patients with anal fissure

PURPOSE

The pathophysiology of anal fissure remains poorly understood. This study examines manometric findings in patients with anal fissure with use of a computer-assisted system, which helps to standardize manometric performance as well as generating longitudinal and cross-sectional profiles of the anal canal.

METHODS

Water-perfused, eight-channel, computer-assisted manometry was performed on 12 patients with chronic anal fissure and compared with 12 age-matched and sex-matched controls.

RESULTS

Mean maximum average resting pressure (MARP) was 120.5 mmHg in patients and 82.6 mmHg in controls (P = 0.0005). Pain was felt during manometry in six patients. In these patients, MARP was 123.2 mmHg, and, in the other six patients, MARP was 117.8 mmHg. Sphincter length was 4.72 cm, and the high pressure zone or that part of the sphincter with pressure more than 50 percent of MARP) was 2.78 cm in length. The high pressure zone/sphincter length ratio was 58 percent compared with 48 percent in controls. Longitudinal profile was bell shaped. Elevated pressures were not confined to the site of the fissure. Cross-sectional analysis showed higher anterior pressures in the distal sphincter. Ultraslow waves were seen in as many as 91 percent of patients and 73 percent of controls. However, ultraslow wave amplitude was 31 mmHg in patients and 15 mmHg in controls (P = 0.03). The rectoanal reflex was normal; overshoot was not seen.

CONCLUSIONS

The primary abnormality in fissure is persistent hypertonia affecting the entire internal sphincter, unrelated to pain. Cross-sectional pressure profiles may explain the predilection of fissures to occur in the posterior midline; other factors must prevent chronic fissures from healing.

Biofeedback training is useful in fecal incontinence but disappointing in constipation

BACKGROUND

Successful biofeedback therapy has been reported in the treatment of fecal incontinence and constipation. It is uncertain which groups of incontinent patients benefit from biofeedback, and our impression has been that biofeedback is more successful for incontinence than for constipation.

PURPOSE

This study was designed to review the results of biofeedback therapy at the Lahey Clinic.

METHODS

Biofeedback was performed using an eight-channel, water-perfused manometry system. Patients saw anal canal pressures as a color bar graph on a computer screen. Assessment after biofeedback was by manometry and by telephone interview with an independent researcher.

RESULTS

Fifteen patients (13 women and 2 men) with incontinence underwent a mean of three (range, 1-7) biofeedback sessions. The cause was obstetric (four patients), postsurgical (five patients), and idiopathic (six patients). Complete resolution of symptoms was reported in four patients, considerable improvement in four patients, and some improvement in three patients. Manometry showed a mean increase of 15.3 (range, -3-30) mmHg in resting pressure and 35.7 (range, 13-57) mmHg in squeezing pressure after biofeedback. A successful outcome could not be predicted on the basis of cause, severity of incontinence, or initial manometry. Twelve patients (10 women and 2 men) with constipation underwent a mean of three (range, 1-14) biofeedback sessions. Each had manometric evidence of paradoxic nonrelaxing external sphincter or puborectalis muscle confirmed by defography or electromyography. All patients could be taught to relax their sphincter in response to bearing down. Despite this, only one patient reported resolution of symptoms, three patients had reduced straining, and three patients had some gain in insight.

CONCLUSIONS

Biofeedback helped 73 percent of patients with fecal incontinence, and its use should be considered regardless of the cause or severity of incontinence or of results on initial manometry. In contrast, biofeedback directed at correcting paradoxic external sphincter contraction has been disappointing.

Human ribosomal protein L37 has motifs predicting serine/threonine phosphorylation and a zinc-finger domain

Ribosomal protein L37 mRNA is overexpressed in colon cancer. The nucleotide sequences of human L37 from several tumor and normal, colon and liver cDNA sources were determined to be identical. L37 mRNA was approximately 375 nucleotides long encoding 97 amino acids with M(r) = 11,070, pI = 12.6, multiple potential serine/threonine phosphorylation sites and a zinc-finger domain. The human sequence is compared to other species.

Nucleotide and deduced amino acid sequence of human ribosomal protein L18

Ribosomal protein L18 mRNA is overexpressed in human colorectal cancer compared to normal colon tissue. We report the nucleotide sequence of human L18 cDNA derived from a normal colon source. There were no mutational changes in segments of L18 cDNA derived from two tumor sources. The L18 cDNA was 690 base pairs long and predicts a single open reading frame of 564 nucleotides, encoding 188 amino acids with a M(r) = 21,621, it is homologous to rat L18 and Xenopus laevis L14.

Prothymosin-alpha mRNA expression correlates with that of c-myc in human colon cancer

Prothymosin alpha (PT-alpha) is a nuclear protein involved in cell proliferation. Transcription of PT-alpha has been reported to be regulated by the c-myc gene in vitro. We identified PT-alpha as being overexpressed in a human colon cancer minus normal mucosa subtraction cDNA library. Northern blot (messenger RNA) analysis showed that both PT-alpha and c-myc genes were overexpressed in human colorectal cancers compared with adjacent normal tissues. Immunohistochemical studies for PT-alpha and c-myc supported these findings. There was no correlation between PT-alpha or c-myc messenger RNA expression and Dukes' stage of colorectal cancer; or between either of these two and actin messenger RNA expression. There was, however, a significant correlation between the PT-alpha expression and c-myc expression (P < 0.001). These findings support the hypothesis that PT-alpha gene transcription may be associated with, and possibly under the control of, the c-myc gene in human colorectal cancers.

Gastric and hepatocellular carcinomas do not overexpress the same ribosomal protein messenger RNAs as colonic carcinoma

The levels of a number of ribosomal protein mRNAs are reported to be increased in human colon cancer. We have assessed whether selected ribosomal protein mRNAs are overexpressed in other gastrointestinal malignancies, namely gastric and hepatocellular carcinomas. Subtracted complementary DNA libraries were generated from paired samples of human (a) colorectal carcinoma minus adjacent normal colonic mucosa and (b) hepatocellular carcinoma minus adjacent normal liver. Screening of approximately 3% of these library clones determined that ribosomal protein mRNAs encoding L18 and L37 (not previously reported) and P0 and S6 were overexpressed in one or the other library. Their complementary DNA inserts were then used as probes to evaluate their expression in a larger number of paired tumor/normal surgical samples of human colonic, gastric, and hepatocellular carcinomas, by Northern hybridization. The mRNA signal was greater in the colonic carcinoma than in paired adjacent normal colonic mucosa in 38 of 42 cases for P0 [tumor/normal (T/N) ratio = 3.0 +/- 0.3, mean +/- SE, P < 0.001] (G. F. Barnard, R. J. Staniunas, S. Bao, K. Mafune, J. L. Gollan, G. D. Steele, Jr., and L. B. Chen, Cancer Res., 52: 3067-3072, 1992), in 25 of 28 cases for L18 (T/N ratio = 3.7 +/- 0.5, P < 0.001), in 27 of 28 cases for L37 (T/N ratio = 5.3 +/- 0.4, P < 0.001), and in 24 of 28 cases for S6 (T/N ratio = 3.1 +/- 0.5, P < 0.01). The level of mRNA overexpression of L18 and S6 did not correlate with the Dukes' stage of disease. In hepatocellular carcinoma samples, using the same four ribosomal protein complementary DNA probes, only P0 mRNA was significantly increased (T/N ratio = 2.8 +/- 0.4, n = 6, P = 0.047). In gastric carcinoma samples, none of these mRNAs was increased (mean T/N ratios = 0.9-1.2, n = 6). Therefore, gastric and hepatocellular carcinomas do not overexpress the same ribosomal protein mRNAs as do colonic carcinoma.

The significance of carbonic anhydrase expression in human colorectal cancer

BACKGROUND

Carbonic anhydrase isoenzymes I and II are present in normal colorectal mucosa. This study aimed to determine if carbonic anhydrase is present in colorectal cancer and what is its potential clinical significance.

METHODS

The messenger RNA (mRNA) and protein expression of carbonic anhydrase isoenzyme I were analyzed in fresh specimens of colorectal adenocarcinoma by Northern and Western blots, respectively. The immunohistochemical expression was subsequently studied in a larger number of formalin-fixed surgical specimens.

RESULTS

All of 30 normal colon samples had a strong RNA hybridization signal. Only 4 of 39 paired colorectal cancer and none of 9 normal liver samples had detectable levels of carbonic anhydrase mRNA. Isoenzyme I protein expression showed similar results. In a separate group of patients, immunohistochemical studies showed that 16 of 96 colorectal tumors had positive staining cells. All positive tumors were well or moderately differentiated carcinomas (P < 0.05). When analyzed retrospectively, immunoreactive cases were more likely to be in a group with a good outcome (P < 0.01) and to lack vascular invasion (P < 0.01) than negative cases.

CONCLUSIONS

The majority of colorectal cancers do not express carbonic anhydrase isoenzyme I. The presence of any isoenzyme I-positive immunoreactive cancer cells may be associated with a more favorable outcome in colorectal cancer.

Extended resection for carcinoma of colon and rectum

Although surgery has been the mainstay of treatment for patients with colorectal carcinoma for more than a century, debate continues regarding the appropriate magnitude of operation for optimal survival. Invasion of contiguous organs is a legitimate indication for extended en bloc resection, including pelvic exenteration, in appropriately selected individuals. Extended lymphadenectomy, especially in resections for carcinoma of the rectum, is being reexamined with renewed enthusiasm. Improved perioperative care has permitted performance of more aggressive operative intervention, with improved cure rates for patients with colorectal neoplasms.

Increased expression of human ribosomal phosphoprotein P0 messenger RNA in hepatocellular carcinoma and colon carcinoma

To search for differentially expressed gene products in selected cancers of endodermal origin, cDNA libraries derived from mRNA in human hepatocellular carcinoma and adjacent grossly normal tissue were generated. From these parent libraries, subtracted cDNA libraries of tumor minus normal and normal minus tumor tissues were constructed. After screening these subtracted libraries by +/- hybridization, a cDNA clone that is overexpressed in hepatocellular carcinoma and encodes the human acidic ribosomal phosphoprotein P0 (P0) was identified. We then evaluated the expression of this phosphoprotein P0 in human colon carcinoma samples. Surgical specimens of primary tumors and liver metastases were examined by Northern hybridization of total RNA with one of 2 32P-labeled P0 probes. The mRNA level of the P0 was greater in primary colon carcinoma than in paired adjacent normal colonic epithelium in 36 of 38 cases; the mean tumor/normal ratio was 2.7 (range, up to 13). The tumor/normal ratio, when plotted against the Dukes' stage of disease, gave evidence for increasing P0 expression with increasing stage of colon carcinoma (P = 0.02). In all 8 cases of paired colon carcinoma metastatic to liver and 2 cases of paired primary hepatocellular carcinoma, the P0 mRNA level was greater in tumor than in adjacent normal liver tissue. The mean tumor/normal ratio was 4.0 (range, up to 11) for the colon cancers metastatic to liver and 4.2 for the primary hepatocellular carcinoma samples. These findings support a common increased expression of selected gene products in different tumors of endodermal origin and suggest that increased P0 expression, in line with certain other ribosomal proteins, may be associated with human colorectal cancer progression and biological aggressiveness.

Solitary colonic metastasis from renal-cell carcinoma 17 years after nephrectomy. Report of a case

Late recurrence of renal-cell carcinoma can present many years after nephrectomy. To the best of our knowledge, we are reporting the first known case of solitary metastatic renal-cell carcinoma to the colon occurring 17 years after nephrectomy.

Ubiquitin hybrid protein gene expression during human colon cancer progression

Ubiquitin is involved in cell-cycle control and DNA replication through a specific proteolytic pathway. Our previous studies demonstrated selected higher expression of a gene encoding ubiquitin-ribosomal protein S27a in poorly differentiated colon carcinoma cell lines. In this study, we evaluated this ubiquitin hybrid protein gene expression in surgical specimens of colon cancers. Northern blot analysis showed that ubiquitin hybrid protein messenger RNA was overexpressed in primary colon cancers compared with adjacent normal colon mucosae in 17 of 20 patients. Dot blot analysis of RNA of 27 tumor samples revealed significantly greater expression in higher Dukes' stage primary colon tumors and liver metastases. These data imply that protein translation machinery is highly activated during progression and metastasis of colon tumors, and that ubiquitin hybrid protein may be useful as a marker of biological aggressiveness.

Diethylcarbamazine-enhanced activation of complement by intact microfilariae of Dirofilaria immitis and their in vitro products

Microfilariae of Dirofilaria immitis and their products inhibited hemolytic complement in sera from various animal species. Inhibition of hemolytic complement activity, fluorescent antibody detection of specific complement proteins binding to microfilarial surfaces, and immunoelectrophoretic evaluation of complement protein C3 conversion demonstrated that (1) intact microfilariae depleted hemolytic complement activity maximally in the presence of diethylcarbamazine whereas the complement-fixing activity of microfilarial products was little affected by diethylcarbamazine; (2) complement proteins C3, properdin, and C5 bound to the cuticular surface of microfilariae; and (3) C3 was converted to a faster-migrating species during incubation with microfilariae or their products. The complement-depleting activity of in vitro products from viable microfilariae was soluble in 10% trichloroacetic acid, resistant to beta-elimination with 0.5 M NaOH, susceptible to treatment with 0.2 M periodate, and composed of 56% neutral sugar, 18% protein, 12% hexosamine, and 10% sulfate. The polysulfated, acidic mucopolysaccharide nature of the surfaces of microfilariae and the results presented here indicate that polyanionic components on worm surfaces or shed by microfilariae react with host complement proteins. This interaction may be enhanced by diethylcarbamazine and contribute to the pathology associated with microfilaremias.