Multiple approaches revealed MGc80-3 as a somatic hybrid with HeLa cells rather than a gastric cancer cell line

The short-tandem-repeats (STR) profiles of MGc80-3 and HeLa partially overlap, raising suspicion of contamination in the MGc80-3 cell line. However, there has not been any relevant study demonstrating whether MGc80-3 was fully replaced by HeLa cells, just mixed with HeLa cells (co-existing), or was a somatic hybrid with HeLa cells. In addition to STR profiling, various approaches, including single nucleotide polymorphisms genotyping, polymerase chain reaction, screening for human papillomaviruses type 18 (HPV-18) fragment, chromosome karyotyping, pathological examination of xenografts, tissue-specific-90-gene expression signature and high-throughput RNA sequencing were used to determine the nature of MGc80-3. Our study found that the abnormal STR profile, partially overlapping with that of HeLa cells (64.62% to 71.64%), could not verify MGc80-3 as a HeLa cell line. However, the STR 13.3 repeat allele in the D13S317 locus that seemed to be unique to HeLa cells was detected in MGc80-3. Almost all the MGc80-3 cells exhibited HPV-18 fragments in the genome as well as certain HeLa marker chromosomes, such as M7 and M12. The molecular assay of the 90-gene expression signature still considered MGc80-3 as a stomach cancer using an algorithmic analysis. The expression pattern of multiple genes in MGc80-3 was quite different from that in HeLa cells, which showed that certain characteristics belonged to gastric cancer cell lines. High throughput RNA sequencing showed the distinct patterns of gene expression in MGc80-3. In conclusion, MGc80-3 cell line is a somatic hybrid with HeLa cells rather than a pure gastric cancer cell line.

Paired-Box Gene 8 (PAX8) and Its Association With Epithelial Carcinomas

Cancer is the second most common culprit of mortality in the United States and epithelial carcinomas are considered as one of the most predominant types of cancer. The association between epithelial cancers and paired-box gene 8 (PAX8) has been studied significantly before. PAX8 belongs to the paired-box gene family, which plays an important role in the organogenesis of different body organ systems, especially the thyroid gland, the renal system, and the Müllerian system. Immunohistochemical staining is being used to detect PAX8 expression in different epithelial cancers and differentiate them from PAX8-negative tumors. In follicular, papillary, and anaplastic thyroid carcinomas, targeting the PAX8/peroxisome proliferator-activated receptors (PPARs) fusion protein is being considered as a potential mechanism for therapy. Moreover, because of its high expression in primary ovarian cancers, PAX8 is being considered as a target for ovarian cancer treatment as well. More studies are needed to test the possibility of using PAX8 as a possible target for managing endometrial carcinomas. In this article, we review the functions of the PAX8 gene, how its mutations lead to the development of certain epithelial carcinomas, how it can be used as a diagnostic or a prognostic marker, and its potential as a therapeutic target for these cancers.

ER-positive endocervical adenocarcinoma mimicking endometrioid adenocarcinoma in morphology and immunohistochemical profile: A case report of application of HPV RNAscope detection

RATIONALE

Usual-type endocervical adenocarcinoma (ECA), high-risk HPV associated, is the most common type of glandular carcinoma in the endocervix. Mucin-depleted usual-type ECA is 1 end of morphological lineage of usual-type ECA and morphologically may show endometrioid features, which could cause diagnostic challenge with uterine endometrioid adenocarcinoma (EEC) and primary endometrioid ECA, especially in the setting of small biopsy and endocervical curettage (ECC).

PATIENT CONCERNS

A 37-year-old women presented with dyspareunia for 1 year, showing atypical glandular cell on a liquid-based Pap TCT examination and positive for HPV16 detection. ECC showed EEC in another hospital based on its "endometrioid" morphology and immunohistochemical profiles (ER/PR/PAX8 strongly positive, though p16 also strongly positive).

DIAGNOSES

The specimen of hysterectomy in our hospital displayed a lesion confined to the uterine cervix showing the same morphology and immunohistochemical profiles as ECC. Finally, we successfully performed HPV RNAscope and detected high-risk human papilloma virus (HPV) E6/E7 mRNA particles in tumor cells in situ, which warranted usual-type ECA with mucin-depleted feature, a rare deviation of usual-type of ECA.

INTERVENTIONS

The patient underwent total hysterectomy with lymph node dissection.

OUTCOMES

To date, 14 months after surgery, the patient is well without recurrence or distant metastasis, and undergoes regular reexamination.

LESSONS SUBSECTIONS

We report a rare case of mucin-depleted usual-type ECA showing overlapping morphological and immunohistochemical profiles with EEC. The pathological diagnosis was confirmed by high-risk HPV RNAscope detection which is superior than immunohistochemistry to identify usual-type ECA, warranting an important role in assisting the diagnosis of morphological vague cases.

The Expression of E6 HPV, P53 and P16ink4a at Well, Moderately, and Poorly Differentiated Cervical Adenocarcinoma

The objective of this study is to analyze the expression of E6 Humanpapilloma virus (HPV), p53, and p16INK4A in cervical adenocarcinoma grade well differentiated (WD), moderately differentiated (MD), and poorly differentiated (PD). A cross sectional study conducted at Department of Anatomic Pathology, Dr. Soetomo General Academic Hospital Surabaya Indonesia using formalin fix paraffin embedded (FFPE) from cervical normal and cervical adenocarcioma grade WD, MD, and PD. The expression of E6 HPV, p53, and p16INK4A was performed by immunohistochemistry (IHC) staining. Data were analyzed with Kruskal-Wallis and continued with Mann-Withney test. The expression of E6 HPV in the cervical adenocarcinoma showed 35.9% specimens represented negative and 64.1% specimens represented positive. There was no significant difference in the expression of E6 HPV and p53 in cervical adenocarcinoma between grade WD, MD, and PD. The p16INK4A was overexpressed, shown as diffuse appearance in 89.7% of the specimens. There was a significant difference in the expression of p16INK4A between grade WD and MD with PD. In conclusion, some of cervical adecarcinoma were not caused by infection of HPV type 16 or 18 and the expression of p16INK4A might take a role in the developing of malignancy that caused by infection of HPV.

Immunohistochemical expression of PAX-8 in Sudanese patients diagnosed with malignant female reproductive tract tumors

Objectives

Paired box protein-8 (PAX-8) immunohistochemical expression can be used as a diagnostic marker for epithelial cells tumors. This study aimed at investigating the immunohistochemical expression of PAX-8 among Sudanese females diagnosed with cervical, endometrial, and ovarian cancers between December 2017 and May 2019 by studying their Formalin-fixed paraffin embedded blocks.

Results

Sixty patients diagnosed with female reproductive tract cancers were included who aged 58.7 ± 6.9 years (range, 43—71). Cervix was the most common cancer site in 51/60 (85%) patients. Regarding cancer stage, there was 17 (28%) and 14 (23%) of the study population had stage 3B and 2B, respectively. The histopathological diagnosis included 20 (44%), 13 (29%), and 12 (27%) poorly, moderately, and well differentiated cervical squamous cell carcinoma (SCC) as well as 11 (73%), 2 (13%), 1 (7%), and 1 (7%) endometrial adenocarcinoma, metastatic adenocarcinoma, endocervical adenocarcinoma, and ovarian mucinous cyst adenocarcinoma, respectively. PAX-8 was positively expressed in 9 endometrial adenocarcinoma, 1 endocervical adenocarcinoma and 1 ovarian mucinous cyst adenocarcinoma, 2 poorly, and 1 moderately differentiated SCC. All patients diagnosed with well differentiated SCC and metastatic adenocarcinoma showed no expression of PAX-8. A statistically significant was seen for PAX-8 expression and the different histopathological diagnosis, P value < 0.001.

Novel immunohistochemical markers in the differential diagnosis of endocervical and endometrial adenocarcinoma: The added benefit of CAIX and PAX8

In a biopsy specimen, adenocarcinomas of the endometrium and uterine cervix may demonstrate significant morphologic overlap. The distinction between these two entities prior to surgical resection is clinically significant as assigning the primary site dictates treatment and prognosis. This diagnostic dilemma is approached by the application of a panel of immunohistochemical stains, traditionally composed of CEA, vimentin, p16, ER, and PR. Most cases are successfully managed with this panel; however, in difficult cases additional tools are needed to suggest a more definitive diagnosis. In this study, we reviewed the efficacy of the customary panel of stains, as well as the added value of new stains in the diagnosis of endocervical adenocarcinoma. Our cohort included biopsy samples of 90 patients (81 endometrial and 9 endocervical adenocarcinomas) with a subsequent hysterectomy for confirmation of diagnosis. This study validated the customary panel of stains and suggests additional markers to aid in the differential diagnosis (PAX8 and CAIX). The addition of PAX8 to the traditional panel increases PPV from 85.71% to 100%. A PPV of 100% may also be attained with fewer stains (five total), with the application of a proposed new panel, which includes PAX8, CAIX, CEA, p16 and ER. This is the first-time differential expression of CAIX has been suggested in the distinction between endocervical and endometrial adenocarcinomas.

Practical Application of Lineage-Specific Immunohistochemistry Markers: Transcription Factors (Sometimes) Behaving Badly

CONTEXT.—

Transcription factors (TFs) are proteins that regulate gene expression and control RNA transcription from DNA. Lineage-specific TFs have increasingly been used by pathologists to determine tumor lineage, especially in the setting of metastatic tumors of unknown primary, among other uses. With experience gathered from its daily application and increasing pitfalls reported from immunohistochemical studies, these often-touted highly specific TFs are not as reliable as once thought.

OBJECTIVES.—

To summarize the established roles of many of the commonly used TFs in clinical practice and to discuss known and potential sources for error (eg, false-positivity from cross-reactivity, aberrant, and overlap "lineage-specific" expression) in their application and interpretation.

DATA SOURCES.—

Literature review and the authors' personal practice experience were used. Several examples selected from the University Health Network (Toronto, Ontario, Canada) are illustrated.

CONCLUSIONS.—

The application of TF diagnostic immunohistochemistry has enabled pathologists to better assess the lineage/origin of primary and metastatic tumors. However, the awareness of potential pitfalls is essential to avoid misdiagnosis.

MSK2 promotes proliferation and tumor formation in squamous cervical cancer via PAX8/RB-E2F1/cyclin A2 axis

Patients with cervical cancer have abnormal cell proliferation and invasion after many years of latency. However, the precise mechanisms remain unclear. Mitogen- and stress-activated kinase 2 (MSK2) is a serine/threonine kinase which displays a phenotype that promotes tumor growth and metastasis in many different types of tumors. The aim of the present study was to determine the effects of MSK2 on the proliferation of cervical cancer cells and elucidate the signaling pathways through which MSK2 exerts its effects in the pathogenesis of squamous cell carcinoma (SCC). Our results confirmed that MSK2 expression was significantly upregulated in cervical cancer cells both in vivo and in vitro. We further found that the expression patterns of paired-box gene 8 (PAX8) and MSK2 were positively correlated in cervical cancer specimens. Moreover, MSK2 knockdown inhibited the phosphorylation of PAX8 and retinoblastoma protein (RB), and suppressed the sequential expressions of cell proliferation factors E2F1 and cyclin A2, resulting in the inhibition of SCC cell proliferation and tumor formation. Thus, this study demonstrates that MSK2 has oncogenic effects in the formation and development of SCC via the PAX8/RB-E2F1/cyclin A2 axis.

Does Strong and Diffuse PAX-8 Positivity Occur in Primary Lung Carcinoma? An Immunohistochemical Study of 418 Cases and Review of the Literature

Although rare cases of PAX-8-positive primary lung carcinoma have been reported, details of staining distribution and intensity in such cases are limited. The aim of this study was to determine whether strong and diffuse PAX-8 staining can occur in primary lung carcinoma. Immunohistochemical staining for PAX-8 (Rabbit polyclonal, 10336-1-AP; Proteintech) was performed on whole-tissue sections from 418 resected primary lung carcinomas. PAX-8 was positive in 5/418 (1.2%) cases, all of which were large cell neuroendocrine carcinomas. Staining was weak to moderate in all 5 cases, and was seen in 5% to 30% of tumor cells. All other primary lung carcinomas (413/418) were negative for PAX-8. This study-the largest series of PAX-8-stained whole-tissue sections of primary lung carcinoma to date-shows that strong and diffuse staining for PAX-8 does not occur in primary lung carcinoma of any type. This staining pattern in a carcinoma in a lung specimen provides strong evidence of nonpulmonary origin.

Uterine Paramesonephric Cysts in Sprague-Dawley Rats from National Toxicology Program Studies

Congenital uterine wall cysts arising from paramesonephric (Müllerian) and mesonephric (Wolffian) ducts are typically incidental findings in most species. We used immunohistochemistry to characterize and determine the origin of uterine cysts in Sprague-Dawley (SD) rats from multigeneration studies conducted by the National Toxicology Program. Subserosal uterine cysts were observed in 20 of the 2,400 SD rats evaluated in five studies, and 10 cysts were characterized for this study. Single cysts were unilocular, fluid-filled, and occurred throughout the uterus. Microscopically, all cysts had a well-developed smooth muscle wall, lined by flattened to cuboidal, sometimes ciliated, epithelium that stained intensely positive for cytokeratin 18 and paired box protein 8 (PAX8). Most cyst epithelia displayed weak to moderate positivity for progesterone receptor (PR) and/or estrogen receptor α (ER-α), as well as were negative for GATA binding protein 3 (GATA3). Cyst lumens contained basophilic flocculent material. The cysts appeared to be developmental anomalies arising from paramesonephric tissue based on positive PAX8 and ER-α and/or PR staining. Additionally, 70% of the cysts lacked GATA3 expression. Taken together, the subserosal uterine cysts observed in adult rats in these studies most likely arose from the paramesonephric duct.

Cervical Adenocarcinoma: Diagnosis of Human Papillomavirus-Positive and Human Papillomavirus-Negative Tumors

CONTEXT

- Cervical adenocarcinomas span a diverse group of tumors with several distinct histologic tumor types, which include endocervical, endometrioid, intestinal, villoglandular, gastric, signet ring, serous, clear cell, and mesonephric. Diagnosis of cervical adenocarcinoma, especially early diagnosis, poses a significant challenge.

OBJECTIVE

- To review the pathogenesis, diagnostic criteria, immunohistochemical markers, and differential diagnosis of various subtypes of human papillomavirus (HPV)-positive and HPV-negative cervical adenocarcinomas. The paper presents a concise summary of the issues that may be particularly difficult in histopathologic diagnosis, such as differentiating neoplastic lesions from benign mimics, determining the tumor type, differentiating early invasive lesions from adenocarcinoma in situ, measuring the depth of invasion, and, finally, differentiating primary cervical adenocarcinoma from uterine endometrioid adenocarcinoma and tumors metastatic from other primary sites.

DATA SOURCES

- The study employed a PubMed search of recently published reports.

CONCLUSIONS

- Early detection of HPV-positive tumor types may be aided with the expansion of HPV testing; however, early diagnosis of HPV-negative cervical adenocarcinomas will continue to pose a challenge and may require the development of additional molecular testing techniques.

Late recurrence of gastric cancer in the ovary and uterine cervix

Uterine cervical metastasis from gastric cancer is relatively rare. This is a report of an extremely rare instance of concurrent late gastric-cancer recurrence to the left ovary and the uterine cervix, 11 years after initial treatment. A 53-year-old woman was referred to our hospital with continuous abdominal pain and genital bleeding. Eleven years prior, she had been treated for gastric cancer, pathologically confirmed as stage II poorly differentiated adenocarcinoma with signet-ring cell carcinoma (pT2N1M0). Magnetic resonance imaging results showed a solid mass in the left ovary, about 8 cm in diameter, fixed to the enlarged uterus and displaying slightly high intensity on T1-weighted images and uneven low intensity and enhanced hypervascular areas on T2-weighted images. Cervical biopsy revealed small, round, spindle-shaped tumor cells beneath a normal cervical epithelium. When we did the immunohistochemistry tests, the tumor cells were positive for cytokeratin 5.2, cytokeratin anion exchange protein 1/3, and cytokeratin 7; the cells were negative for cytokeratin 20 and paired-box gene (PAX) 8. This marker pattern was the same as that of her previous gastric cancer; therefore, the tumors of the cervix and left ovary were diagnosed as metastatic gastric cancer. After obtaining informed consent, the patient received transarterial chemoembolization using cisplatin and, subsequently, underwent a modified radical hysterectomy, bilateral salpingo-oophorectomy. Pathological examination revealed an infiltrative pattern with poorly differentiated adenocarcinoma and signet-ring cell carcinoma. The patient received combination chemotherapy with cisplatin and S-1, and she is currently alive 12 months after surgery with no evidence of recurrence. Late recurrence more than 10 years after treatment for primary gastric cancer is extremely rare. Clinicians should be aware of the possibility of metastasis from extrapelvic carcinomas, even in patients treated many years prior to presentation.