HER-2/neu oncogene amplification in cervical cancer studied by fluorescent in situ hybridization

Surface plasmon biosensor based on Bi2Te3 antimonene heterostructure for the detection of cancer cells

This theoretical investigation proposes the preliminary stage detection of cancer cells using a prism-based surface plasmon resonance biosensor. The surface plasmon resonance (SPR) biosensor is label-free and rapid; it supports real-time investigations, including greater sensitivity, and it has an enormous possibility for detecting different forms of cancer. The refractive index alteration of cancer cells is 1.360-1.401. The performance of the SPR sensor has been analyzed. The different types of cancer cells for skin, cervical, blood, adrenal, and breast (type I and II) have been analyzed, and sensitivities of 292, 384, 229, 242, 254, and 261 (degree/RIU) have been achieved, respectively. A high figure of merit of 115.2RIU^-1 has been achieved for HeLa cells and achieved detection accuracy of 0.32deg^-1 for basal cells.

Prevalence of HER2 overexpression and amplification in cervical cancer: A systematic review and meta-analysis

The reported rates of HER2 positivity in cervical cancer (CC) range from 0% to 87%. The importance of HER2 as an actionable target in CC would depend on HER2 positivity prevalence. Our aim was to provide precise estimates of HER2 overexpression and amplification in CC, globally and by relevant subgroups. We conducted a PRISMA compliant meta-analytic systematic review. We searched Medline, EMBASE, Cochrane database, and grey literature for articles reporting the proportion of HER2 positivity in CC. Studies assessing HER2 status by immunohistochemistry or in situ hybridization in invasive disease were eligible. We performed descriptive analyses of all 65 included studies. Out of these, we selected 26 studies that used standardized American Society of Clinical Oncology / College of American Pathologists (ASCO/CAP) Guidelines compliant methodology. We conducted several meta-analyses of proportions to estimate the pooled prevalence of HER2 positivity and subgroup analyses using geographic region, histology, tumor stage, primary antibody brand, study size, and publication year as moderators. The estimated pooled prevalence of HER2 overexpression was 5.7% (CI 95%: 1.5% to 11.7%) I2 = 87% in ASCO/CAP compliant studies and 27.0%, (CI 95%: 19.9% to 34.8%) I2 = 96% in ASCO/CAP non-compliant ones, p < 0.001. The estimated pooled prevalence of HER2 amplification was 1.2% (CI 95%: 0.0% to 5.8%) I2 = 0% and 24.9% (CI 95%: 12.6% to 39.6%) I2 = 86%, respectively, p = 0.004. No other factor was significantly associated with HER2 positivity rates. Our results suggest that a small, but still meaningful proportion of CC is expected to be HER2-positive. High heterogeneity was the main limitation of the study. Variations in previously reported HER2 positivity rates are mainly related to methodological issues.

Gene amplification and immunohistochemical expression of ERBB2 and EGFR in cervical carcinogenesis. Correlation with cell-cycle markers and HPV presence

Although the members of the epidermal growth factor receptor family ERBB2 and EGFR are important therapeutic targets in the treatment of malignant neoplasias, little is known about their role in cervical carcinogenesis. Our objective was to evaluate the dysfunction of ERBB2 and EGFR at the gene copy number and protein expression level in neoplastic lesions of the uterine cervix with the aim of obtaining information about its role in cervical carcinogenesis and their possible use as therapeutic targets in these diseases. We studied gene amplification and protein expression of ERBB2 and EGFR and their relationship with Ki67, p16 and p53 and HPV presence in 22 normal/benign (N/B) cervices, 20 low-grade squamous intraepithelial lesions (LSILs), 70 high-grade SILs (HSILs) and 32 invasive squamous cervical carcinomas (ISCCs). No cases showed selective amplification of ERBB2 or EGFR but corresponding chromosome-specific probes displayed chromosome 17 and 7 polyploidy associated with the grade of the lesion (p<0.0001 and p=0.004, respectively) and with the positive expression of Ki67 and p16 (p<0.01). Concurrent polyploidy for both chromosomes was statistically related (p<0.0001). ERBB2 immunohistochemical expression was not observed in any of the study cases except for one ISCC but EGFR was associated with higher-grade lesions (N/B plus LSIL 21.4% vs. HSIL plus ISCC 45.5%; p=0.007). No association was observed between EGFR expression and that of cell-cycle markers or HPV presence. Increased copy number of EGFR and ERBB2 is due to polyploidy of 7 and 17 chromosomes, this being a phenomenon associated with lesion severity and with an increase in the expression of cell-cycle markers. EGFR, but not ERBB2, is expressed in precursor lesions of squamous cervical neoplasia and is related to the neoplastic progression but not to proliferation marker expression and therefore ERBB2 and this calls into question the usefulness of ERBB2 as a therapeutic target.

HER2 expression in cervical cancer as a potential therapeutic target

BACKGROUND

Trastuzumab, a humanized monoclonal antibody against the HER2 receptor is currently being used in breast and other tumor types. Early studies have shown that a variable proportion of cervical carcinoma tumors overexpress the HER2 receptor as evaluated by diverse techniques and antibodies. Currently it is known that a tumor response to trastuzumab strongly correlates with the level of HER2 expression evaluated by the Hercep Test, thus, it seems desirable to evaluate the status of expression of this receptor using the FDA-approved Hercep Test and grading system to gain insight in the feasibility of using trastuzumab in cervical cancer patients.

METHODS

We analyzed a series of cervical cancer cell lines, the primary tumors of 35 cases of cervical cancer patients and four recurrent cases, with the Hercep Test in order to establish whether this tumor type overexpress HER2 at level of 2+/3+ as trastuzumab is currently approved for breast cancer having such level of expression.

RESULTS

The results indicate that only 1 out of 35 primary tumors cases overexpress the receptor at this level, however, two out of four recurrent tumors that tested negative at diagnosis shifted to Hercep Test 2+ and 3+ respectively.

CONCLUSIONS

The low frequency of expression in primary cases suggests that trastuzumab could have a limited value for the primary management of cervical cancer patients, however, the finding of "conversion" to Hercep Test 2+ and 3+ of recurrent tumors indicates the need to further evaluate the expression of HER2 in the metastatic and recurrent cases.

The use of trastuzumab in the treatment of hormone refractory prostate cancer; phase II trial

PURPOSE

To investigate the efficacy and toxicity of the antibody to the HER-2/neu receptor (trastuzumab, Herceptin) in the treatment of advanced hormone-refractory prostate cancer (HRPC).

MATERIALS AND METHODS

Eighteen patients with HRPC were recruited for this phase II trial in which they received trastuzumab for 12 weeks or until disease progression or unacceptable toxicity was documented. HER-2 receptor overexpression was evaluated using immunohistochemistry (IHC) and dual-color fluorescence in-situ hybridization (FISH) assays.

RESULTS

Trastuzumab as a single agent demonstrated little efficacy in treating HRPC. Two patients demonstrated stable disease based on a decrease in PSA level to less than 50% of baseline. No patient demonstrated a regression of radiographic bony or soft tissue metastatic disease. The medication was well tolerated in 16 patients (89%), and 2 patients (11%) had to be hospitalized for cardiac complications.

CONCLUSIONS

Trastuzumab (Herceptin) as a single agent demonstrated poor efficacy in treating HRPC. Based on promising results in treating breast cancer with regimens using Herceptin and cytotoxic agents, a similar combination approach might demonstrate better efficacy in treating HRPC.

Selection of HER-2/neu-positive tumor cells in early stage cervical cancer: implications for Herceptin-mediated therapy

OBJECTIVE

The purpose of this study was to compare HER-2/neu expression on biopsies obtained from early stage cervical cancer, primary cell lines established therefrom, established cervical cancer cell lines, and metastatic or recurrent sites of disease; and to evaluate the sensitivity of primary cervical cancer cell lines to treatment with a humanized MAb against HER-2/neu (Herceptin).

METHODS

Surface HER-2/neu expression on 18 cervical cancer cell lines was compared to HER-2/neu detection by immunohistochemistry on biopsies obtained from the original tumors (10 patients) and sites of recurrence (2 patients). Primary cell lines were tested for sensitivity to Herceptin-mediated antibody-dependent cellular cytotoxicity (ADCC) and sensitivity to Herceptin-mediated inhibition of proliferation.

RESULTS

Nine out of 10 primary (90%) and 8 out of 8 (100%) established cervical cancer cell lines expressed HER-2/neu by flow cytometry. Surprisingly, all HER-2/neu-positive primary cell lines were derived from tumor biopsies that scored negative (i.e., 0 to 1+) for HER-2/neu expression by immunohistochemistry. Heavy staining for HER-2/neu (i.e., 3+) was found in the recurrent/metastatic lesions of the two relapsed patients. Importantly, all HER-2/neu-positive primary cell lines were highly sensitive to Herceptin-mediated ADCC, and their proliferation was also significantly inhibited by Herceptin. A significant enhancement of Herceptin-mediated ADCC was demonstrated when effector cells were exposed to low doses of IL-2 in vitro.

CONCLUSIONS

Early stage cervical cancer may develop a population of HER-2/neu-positive cells with a selective growth advantage over HER-2/neu-negative cells. Therapy which targets HER-2/neu may be more effective in patients with cervical cancer than indicated by the commonly low expression of HER-2/neu in tumors removed at the time of primary treatment.

Loss of sequences on the short arm of chromosome 17 is a late event in squamous carcinoma of the cervix

AIMS

To determine by fluorescence in situ hybridisation (FISH) whether deletion of D17S34, a subtelomeric probe for 17p, occurs in invasive squamous carcinoma of the cervix, and to determine the extent of such loss by analysis of the p53 and HER2/NEU genes.

METHODS

Fourteen invasive squamous cell carcinomas of the cervix were investigated by FISH for D17S34, p53, and HER2/NEU. Dual hybridisation of each probe with the chromosome 17 alpha satellite (D17Z1) probe was performed on paraffin wax embedded sections, and the fluorescence ratios of the paired signals were determined. Broad spectrum human papillomavirus (HPV) typing by ISH and GP5+/6+ polymerase chain reaction was also performed.

RESULTS

Twelve tumours were HPV positive, nine with HPV-16, and one each with types 18, 31, and 39. Loss of D17S34 was identified in four tumours, one of which was HPV negative. In one tumour, D17S34 loss was accompanied by loss of p53 only, suggesting that deletion was limited to the p arm. A second tumour showed simultaneous losses of all probes, indicative of whole chromosome 17 loss during tumour growth. The two remaining specimens showed loss of D17S34 only, diffuse in one, and localised within the tumour in the other. Aberrations of p53 or HER2/NEU were not seen independently of D17S34 loss, and loss did not correlate with HPV presence or type.

CONCLUSIONS

These data show that D17S34 loss is prevalent, marking 28% of the invasive squamous carcinomas in this study. The observed intratumoral heterogeneity indicates that, at least in some cases, this loss occurs after invasion and is therefore a late event in the path of cervical carcinogenesis.

Fluorescent in situ hybridization study of c-myc oncogene copy number in prostate cancer

We previously conducted a study of 88 cases of prostate cancer in an attempt to identify potential prognostic biomarkers that can distinguish aggressive cases that must be treated immediately. Prostate cancer is a serious disease affecting men worldwide and compromises the quality of life of its patients. Biomarkers studied included chromosome 7 trisomy, chromosome 8 trisomy, and HER-2/neu oncogene amplification. These biomarkers were initially studied because trisomy 8 and oncogene amplification of the HER-2/neu gene have been reported in many other cancers, including those studied in this laboratory. In view of the fact that HER-2/neu amplification was not found to play a prominent role in the group of prostate cancer specimens that we studied, an exploration of other biomarkers was felt to be warranted. Thus, we began a pilot study of c-myc oncogene copy number in prostate cancer using the same protocol for fluorescent in situ hybridization and a direct-labeled SpectrumOrange LSI c-myc probe (Vysis, Inc., Downers Grove, IL) on formalin-fixed, paraffin-embedded tissue. From a total of 36 cases of prostate cancers successfully analyzed, we found 11 (31%) tumors exhibiting 3 or more positive signals for c-myc in 15% or more of the cells. Of these, only 7 tumors (19% of the total cases studied) had >/=3 signals in 20% or more of the cells. No case had >/=3 signals in 25% or more of the cells. Compared to other molecular probes tested, the c-myc signals were more faint and the quality of the preparation was less optimal than other tumor specimens that we previously studied. Based on the information available thus far, we conclude that an increased copy number in c-myc oncogene copy number was not a prominent finding in our cohort of prostate cancer patients.