Usefulness of high-risk human papillomavirus mRNA silver in situ hybridization diagnostic assay in oropharyngeal squamous cell carcinomas

Pathology, research and practice

2021 Aug 14

Gale, N;Poljak, M;Volavšek, M;Hošnjak, L;Velkavrh, D;Bolha, L;Komloš, KF;Strojan, P;Aničin, A;Zidar, N;
PMID: 34455364 | DOI: 10.1016/j.prp.2021.153585

The transcriptional activity of high-risk human papillomaviruses (HR-HPV) within oropharyngeal squamous cell carcinomas (OPSCC) has been linked to improved survival of patients. HR-HPV mRNA silver in situ hybridization (SISH) was evaluated on a cohort of OPSCC and compared with viral HPV DNA tests and p16 expression. Clinical outcomes of HPV-driven OPSCC and non-HPV related OPSCC were also studied.We evaluated 67 OPSCC and 3 papillomas, obtained from 62 patients, for detection of HR-HPV DNA by PCR tests. The positive samples were additionally studied by the SISH method using three probes of HPV16, HPV18, and HP33, and for p16 expression detected by immunohistochemistry. SISH assays were evaluated for the presence/number and intensity of signals in cancer cells. Prognostic significance of HPV status in our cohort was evaluated with univariate and multivariate statistics.According to the HR-HPV PCR tests, 46 (69%) OPSCC cases were HPV positive, while three papillomas were negative. Of total 46 HPV-positive OPSCCs, 43 cases were also SISH-positive, while p16 overexpression was found in 45 of 46 HPV positive OPSCC cases. In OPSCC specimens, the sensitivity and specificity of the combined SISH probes (HPV16 and 33) were both 100.00%, when compared to HPV PCR. HPV positivity of the tumors appeared significant for predicting progression-free survival, cause specific survival and overall survival in a multivariate setting.The recently developed mRNA SISH methodology can detect HPV-driven OPSCCs without any additional test in 79% of cases. Positive SISH signals enable the visualization of viral transcripts required to recognize clinically relevant HPV infection. However, rare and tiny signals require an experienced pathologist to establish a consensus interpretation of results. The currently applied HR-HPV mRNA SISH analysis may serve as a groundwork for additional studies.

Differences in the Prevalence of Human Papillomavirus (HPV) in Head and Neck Squamous Cell Cancers by Sex, Race, Anatomic Tumor Site, and HPV Detection Method.

JAMA Oncol.

2016 Dec 08

D'Souza G, Westra WH, Wang SJ, van Zante A, Wentz A, Kluz N, Rettig E, Ryan WR, Ha PK, Kang H, Bishop J, Quon H, Kiess AP, Richmon JD, Eisele DW, Fakhry C.
PMID: 27930766 | DOI: 10.1001/jamaoncol.2016.3067

Abstract

IMPORTANCE:

Human papillomavirus (HPV) causes an increasing proportion of oropharyngeal squamous cell carcinomas (OPSCCs), particularly in white men. The prevalence of HPV among other demographic groups and other anatomic sites of HNSCC is unclear.

OBJECTIVE:

To explore the role of HPV tumor status among women and nonwhites with OPSCC and patients with nonoropharyngeal head and neck squamous cell carcinoma (non-OP HNSCC).

DESIGN, SETTING, AND PARTICIPANTS:

Retrospective cohort study at 2 tertiary academic centers including cases diagnosed 1995 through 2012, oversampled for minorities and females. A stratified random sample of 863 patients with newly diagnosed SCC of the oral cavity, oropharynx, larynx, or nasopharynx was used.

MAIN OUTCOMES AND MEASURES:

Outcomes were HPV status as measured by p16 immunohistochemical analysis, HPV16 DNA in situ hybridization (ISH), and high-risk HPV E6/E7 mRNA ISH.

RESULTS:

Of 863 patients, 551 (63.9%) were male and median age was 58 years (interquartile range, 51-68 years). Among 240 OPSCCs, 144 (60%) were p16 positive (p16+), 115 (48%) were HPV16 DNA ISH positive (ISH16+), and 134 (56%) were positive for any oncogenic HPV type (ISH+). From 1995 to 2012, the proportion of p16+ OPSCC increased significantly among women (from 29% to 77%; P = .005 for trend) and men (36% to 72%; P < .001 for trend), as well as among whites (39% to 86%; P < .001 for trend) and nonwhites (32% to 62%; P = .02 for trend). Similar results were observed for ISH+ OPSCC (P ≤ .01 for all). Among 623 non-OP HNSCCs, a higher proportion were p16+ compared with ISH positive (62 [10%] vs 30 [5%]; P = .001). A high proportion (26 of 62 [42%]) of these p16+ non-OP HNSCCs were found in sites adjacent to the oropharynx. The proportion of p16+ and ISH+ non-OP HNSCCs were similar by sex. Over time, the proportion of non-OP HNSCCs that were p16+ (or ISH+) increased among whites (P = .04 for trend) but not among nonwhites (each P > .51 for trend). Among OPSCCs, p16 had high sensitivity (100%), specificity (91%), and positive (93%) and negative predictive value (100%) for ISH positivity. In non-OP HNSCCs, p16 had lower sensitivity (83%) and positive predictive value (40%) but high specificity (94%) and negative predictive value (99%) for ISH positivity.

CONCLUSIONS AND RELEVANCE:

During 1995 through 2012, the proportion of OPSCCs caused by HPV has increased significantly. This increase was not restricted to white men but was a consistent trend for women and men, as well as for white and nonwhite racial groups. Few non-OP HNSCCs were HPV related. P16 positivity was a good surrogate for ISH+ tumor status among OPSCC, but not a good surrogate for non-OP HNSCC.

Human papilloma virus testing in oropharyngeal squamous cell carcinoma: What the clinician should know.

Oral oncology, 50(1):1–9.

Mirghani H1, Amen F2, Moreau F3, Guigay J4, Ferchiou M5, Melkane AE6, Hartl DM7, Lacau St Guily J (2014).
PMID: 24169585 | DOI: 10.1016/j.oraloncology.2013.10.008.

High risk Human Papilloma virus (HR-HPV) associated oropharyngeal cancers are on the increase. Although, the scientific community is aware of the importance of Human Papilloma Virus (HPV) testing, there is no consensus on the assays that are required to reliably identify HR-HPV related tumors. A wide range of methods have been developed. The most widely used techniques include viral DNA detection, with polymerase chain reaction (PCR) or In Situ Hybridization, and p16 detected by immunohistochemistry. However, these tests provide different information and have their own specific limitations. In this review, we summarize these different techniques, in light of the recent literature. p16 Overexpression, which is an indirect marker of HPV infection, is considered by many head and neck oncologists to be the most important marker for patient stratification. We describe the frequent lack of concordance of this marker with other assays and the possible reasons for this. The latest developments in HPV testing are also reported, such as the RNAscope™ HPV test, and how they fit into the existing framework of techniques. HPV testing must not be considered in isolation, as there are important interactions with other parameters, such as tobacco exposure. This is an important and rapidly evolving field and is likely to become pivotal to staging and choice of treatment of oropharyngeal carcinoma in the future.

"Transcriptionally Active High-Risk Human Papillomavirus is Not a Common Etiologic Agent in the Malignant Transformation of Inverted Schneiderian Papillomas. "

Head Neck Pathol.

2017 Feb 08

Rooper LM, Bishop JA, Westra WH.
PMID: 28181187 | DOI: 10.1007/s12105-017-0779-0

The role of human papillomavirus (HPV) as an etiologic and transformational agent in inverted Schneiderian papilloma (ISP) is unclear. Indeed, reported detection rates of HPV in ISPs range from 0 to 100%. The true incidence has been confounded by a tendency to conflate high- and low-risk HPV types and by the inability to discern biologically relevant from irrelevant HPV infections. The recent development of RNA in situ hybridization for high-risk HPV E6/E7 mRNA now allows the direct visualization of transcriptionally active high-risk HPV in ISP, providing an opportunity to more definitively assess its role in the development and progression of ISPs. We performed p16 immunohistochemistry and high-risk HPV RNA in situ hybridization on 30 benign ISPs, 7 ISPs with dysplasia, 16 ISPs with carcinomatous transformation, and 7 non-keratinizing squamous cell carcinomas (SCCs) with inverted growth that were unassociated with ISP. Transcriptionally active HPV was not detected in any of the 52 ISPs including those that had undergone carcinomatous transformation, but it was detected in two of seven (29%) non-keratinizing SCCs that showed inverted growth. There was a strong correlation between high-risk HPV RNA in situ hybridization and p16 immunohistochemistry (97%; p < 0.01). These results indicate that transcriptionally active high-risk HPV does not play a common role in either the development of ISP or in its transformation into carcinoma.

In situ hybridization detection methods for HPV16 E6/E7 mRNA in identifying transcriptionally active HPV infection of oropharyngeal carcinoma: an updating

Human Pathology

2017 Oct 06

Volpi CC, Ciniselli CM, Gualeni AV, Plebani M, Alfieri S, Verderio P, Locati L, Perrone F, Quattronea P, Carbone A, Pilotti S, Gloghini A.
PMID: 28993274 | DOI: 10.1016/j.humpath.2017.09.011

The aim of this study is comparing two in situ hybridization (ISH) detection methods for human papilloma virus (HPV) 16 E6/E7 mRNA, i.e. the RNAscope™ 2.0 High Definition (HD) and the upgraded RNAscope™ 2.5 HD version. The RNAscope™ 2.5 HD has recently replaced the RNAscope™ 2.0 HD detection kit. Therefore, this investigation starts from the need to analytically validate the new mRNA ISH assay and, possibly, to refine the current algorithm for HPV detection in oropharyngeal squamous cell carcinoma (OSCC) with the final goal to apply it to daily laboratory practice. The study was based on HPV status and on generated data, interpreted by a scoring algorithm. The results highlighted that the compared RNAscope HPV tests had a good level of interchangeability and enabled to identify OSCC that are truly driven by high risk-HPV infection. This was also supported by the comparison of the RNAscope HPV test with HPV E6/E7 mRNA real time reverse transcriptase-polymerase chain reaction (RT-PCR), in a fraction of cases where material for HPV E6/E7 mRNA real time RT-PCR was available. Furthermore, the algorithm that associates p16 immunohistochemistry (IHC) with the identification of HPV mRNA by RNAscope was more effective than the one that associated p16 IHC with the identification of HPV DNA by ISH.

Diagnosis of HPV driven oropharyngeal cancers: Comparing p16 based algorithms with the RNAscope HPV-test

Oral Oncology

2016 Oct 15

Mirghani H, Casiraghi O, Guerlain J, Amen F, He MX, Ma XJ, Luo Y, Mourareau C, Drusch F, Lakdhar AB, Melkane A, St Guily L, Badoual C, Scoazec JY, Borget I, Aupérin A, Dalstein V, Vielh P.
PMID: - | DOI: http://dx.doi.org/10.1016/j.oraloncology.2016.10.009

Abstract

Background

Accurate identification of HPV-driven oropharyngeal cancer (OPC) is a major issue and none of the current diagnostic approaches is ideal. An in situ hybridization (ISH) assay that detects high-risk HPV E6/E7 mRNA, called the RNAscope HPV-test, has been recently developed. Studies have suggested that this assay may become a standard to define HPV-status.

Methods

To further assess this test, we compared its performance against the strategies that are used in routine clinical practice: p16 immunohistochemistry (IHC) as a single test and algorithms combining p16-IHC with HPV-DNA identification by PCR (algorithm-1) or ISH (algorithm-2).

Results

105 OPC specimens were analyzed. The prevalence of HPV-positive samples varied considerably: 67% for p16-IHC, 54% for algorithm-1, 61% for algorithm-2 and 59% for the RNAscope HPV-test. Discrepancies between the RNAscope HPV-test and p16-IHC, algorithm-1 and 2 were noted in respectively 13.3%, 13.1%, and 8.6%.

The 4 diagnostic strategies were able to identify 2 groups with different prognosis according to HPV-status, as expected. However, the greater survival differential was observed with the RNAscope HPV-test [HR: 0.19, 95% confidence interval (CI), 0.07–0.51, p = 0.001] closely followed by algorithm-1 (HR: 0.23, 95% CI, 0.08–0.66, p = 0.006) and algorithm-2 (HR: 0.26, 95% CI, 0.1–0.65, p = 0.004). In contrast, a weaker association was found when p16-IHC was used as a single test (HR: 0.33, 95% CI, 0.13–0.81, p = 0.02).

Conclusions

Our findings suggest that the RNAscope HPV-test and p16-based algorithms perform better that p16 alone to identify OPC that are truly driven by HPV-infection. The RNAscope HPV-test has the advantage of being a single test.

HR-HPV E6/E7 mRNA In Situ Hybridization: Validation Against PCR, DNA In Situ Hybridization, and p16 Immunohistochemistry in 102 Samples of Cervical, Vulvar, Anal, and Head and Neck Neoplasia.

Am J Surg Pathol.

2017 May 01

Mills AM, Dirks DC, Poulter MD, Mills SE, Stoler MH.
PMID: 28403015 | DOI: 10.1097/PAS.0000000000000800

Dysregulated expression of oncogenic types of E6 and E7 is necessary for human papillomavirus (HPV)-driven carcinogenesis. An HPV E6/E7 mRNA in situ hybridization (ISH) assay covering 18 common high-risk types ("HR-RISH," aka HR-HPV RNA18 ISH) has not been extensively studied in the anogenital tract or validated on automated technology. We herein compare HR-RISH to DNA polymerase chain reaction (PCR), p16 immunohistochemistry, and a previously available HPV DNA ISH assay in HPV-related anogenital and head and neck (H&N) neoplasia. A total of 102 squamous intraepithelial lesions (16 CIN1, 25 CIN3, 3 AIN1, 12 AIN3, 9 VIN3)/invasive squamous cell carcinomas (17 cervical, 2 anal, 18 H&N) as well as 10 normal and 15 reactive cervix samples were collected. HR-RISH, DNA ISH, and p16 immunohistochemistry were performed on whole formalin-fixed, paraffin-embedded sections. RNA ISH for 6 low-risk HPV types (LR-RISH) was also performed. RNA and DNA ISH assays used automated systems. HR-HPV PCR was performed on morphology-directed formalin-fixed, paraffin-embedded punches. HR-RISH was ≥97% sensitive for PCR+ and p16+ neoplasia, as well as morphologically defined anogenital high grade squamous intraepithelial lesion/invasive squamous cell carcinoma. HR-RISH was also positive in 78% of anogenital low grade squamous intraepithelial lesion, including 81% of CIN1. Furthermore, a subset of PCR-negative/invalid and p16-negative lesions was positive for HR-RISH. Only 1 problematic reactive cervix sample and no normal cervix samples stained. These results demonstrate that HR-RISH is a robust method for the detection of HR-HPV-related neoplasia and provides insight into HPV pathobiology. Performance meets or exceeds that of existing assays in anogenital and H&N lesions and may play a role in resolving diagnostically challenging CIN1 versus reactive cases.

The presence of high-risk human papillomavirus (HPV) E6/E7 mRNA transcripts in a subset of sinonasal carcinomas is evidence of involvement of HPV in its etiopathogenesis.

Virchows Arch. 2015 Jul 31.

Laco J, Sieglová K, Vošmiková H, Dundr P, Němejcová K, Michálek J, Čelakovský P, Chrobok V, Mottl R, Mottlová A, Tuček L, Slezák R, Chmelařová M, Sirák I, Vošmik M, Ryška A.
PMID: 26229021

The aim of the study was to investigate prevalence of high-risk human papillomavirus (HR-HPV) infection in sinonasal carcinomas by immunohistochemistry, in situ hybridization, and polymerase chain reaction, detecting p16INK4a protein (p16) expression and presence of both HPV DNA and HPV E6/E7 messenger RNA (mRNA). The study comprised 47 males and 26 females, aged 23-83 years (median 62 years), mostly (67 %) with a squamous cell carcinoma (SCC). Of the tumors, 53 % arose in the nasal cavity, 42 % in the maxillary sinus, and 5 % in the ethmoid complex. The follow-up period ranged 1-241 months (median 19 months). HPV16, HPV18, or HPV35 were detected in 18/73 (25 %) tumors, 17 SCCs, and 1 small cell neuroendocrine carcinoma. There was a strong correlation between results of HPV detection methods and p16 expression (p < 0.005). HPV-positive SCCs occurred more frequently in smokers (p = 0.04) and were more frequently p16-positive (p < 0.0001) and nonkeratinizing (p = 0.02), the latter occurring more commonly in nasal cavity (p = 0.025). Median survival for HPV-positive SCC patients was 30 months, while for HPV-negative SCC patients was 14 months (p = 0.23). In summary, we confirm that HR-HPV is actively involved in the etiopathogenesis of a significant subset of sinonasal SCCs. p16 may be used as a reliable surrogate marker for determination of HPV status also in sinonasal SCCs. Although we observed a trend toward better overall survival in HPV-positive SCCs, the prognostic impact of HPV status in sinonasal carcinomas needs to be elucidated by further studies.

Spindle Cell Carcinomas of the Head and Neck Rarely Harbor Transcriptionally-Active Human Papillomavirus.

Head and neck pathology, ;7(3):250–257.

Watson RF, Chernock RD, Wang X, Liu W, Ma XJ, Luo Y, Wang H, El-Mofty SK, Lewis JS Jr (2013).
PMID: 23536041 | DOI: 10.1007/s12105-013-0438-z.

Spindle cell carcinoma is an uncommon variant of squamous cell carcinoma characterized by spindled or pleomorphic cells which appear to be a true sarcoma but are actually epithelial. Some head and neck squamous cell carcinoma variants can be human papillomavirus (HPV)-related and have improved outcomes. We sought to determine if spindle cell carcinomas are associated with transcriptionally-active HPV. Cases of spindle cell carcinoma were retrieved from department files. Transcriptionally-active HPV was determined by mRNA in situ hybridization for high risk HPV E6 and E7 transcripts and by a surrogate marker, p16 immunohistochemistry, with a 50% staining cutoff. RT-PCR for high risk HPV mRNA was performed on the cases that were technical failures by in situ hybridization. Medical records and follow up information were retrieved for all patients. Of 31 cases, 5 were from the oropharynx, 12 from the oral cavity, and 14 from the larynx or hypopharynx. One purely spindled oral cavity spindle cell carcinoma was HPV positive. It was also diffusely positive for p16. Another laryngeal spindle cell carcinoma was HPV positive in both the squamous and spindle cell components, but was negative for p16. None of the five oropharyngeal spindle cell carcinomas were positive for p16 or HPV RNA. The HPV positive patients both presented at high stage (IV) and died with disease within 2 years of diagnosis. The majority of spindle cell carcinomas of the head and neck, including those arising in the oropharynx, are not related to transcriptionally active HPV. Although the number of cases is too small for any definitive conclusions, for the rare HPV positive spindle cell carcinoma cases, positive viral status does not appear to confer any prognostic benefit.

Adenosquamous Carcinoma of the Head and Neck: Relationship to Human Papillomavirus and Review of the Literature.

Head & Neck Pathology, 5(2):108–116.

Masand RP, El-Mofty SK, Ma XJ, Luo Y, Flanagan JJ, Lewis JS Jr (2011).
PMID: 21305368 | DOI: 10.1007/s12105-011-0245-3.

Adenosquamous carcinoma (ADSC) of the head and neck is an aggressive variant of squamous cell carcinoma (SCC). Certain variants of head and neck SCC are human papillomavirus (HPV)-related and have better prognosis. The relationship of HPV to head and neck ADSC has not been investigated. We searched our files for the term "adenosquamous" and head and neck subsites and found cases from 1998 to 2009. The requisite histologic criteria were the presence of SCC combined with distinct gland formation and/or intracellular mucin. DNA in situ hybridization for high-risk HPV, RNA in situ hybridization for high risk HPV E6 and E7 transcripts, and immunohistochemistry for p16 and p53 were performed. The existing literature on ADSC was also reviewed. Of the 18 cases, eight were from the larynx and hypopharynx, four from the oral cavity, three from the oropharynx, and three from the nasal cavity. Three cases (16%) showed both high risk HPV E6 and E7 and p16 expression, one from the nasal cavity and two from the oropharynx. Both oropharyngeal carcinoma patients were alive and disease free at 34 and 103 months, respectively. ADSCs of the head and neck are a heterogeneous group of tumors. A small minority of cases harbor HPV and most of these, particularly those occurring at sites with known high prevalence of HPV, show active viral transcription with detectable E6 and E7 and overexpression of p16. The HPV-related oropharyngeal cases, though rare, appear to do very well clinically, while the remaining cohort of ADSC patients do quite poorly. Head and neck ADSC appears to be a mixed variant that can be further classified according to its HPV status.

Diagnosis of HPV-driven head and neck cancer with a single test in routine clinical practice.

Mod Pathol.

2015 Sep 25

Mirghani H, Casiraghi O, Amen F, He M, Ma XJ, Saulnier P, Lacroix L, Drusch F, Ben Lakdhar A, Saint Guily JL, Badoual C, Scoazec JY, Vielh P.
PMID: 26403782 | DOI: 10.1038/modpathol.2015.113

Abstract

Accurate screening of HPV-driven head and neck squamous cell carcinoma is a critical issue. Although there are commercial direct and indirect assays for HPV-related head and neck squamous cell carcinoma, none are ideal. Recently, a novel RNA in situ hybridization test (the RNAscope HPV-test) has been developed for the detection of high-risk HPV E6/E7 mRNA in formalin-fixed paraffin-embedded tissue. However, validation of this assay against the 'gold standard' (identification of high-risk HPV E6/E7 mRNA in fresh-frozen tissue by quantitative real-time (qRT)-PCR) has only been reported by one team. Formalin-fixed paraffin-embedded samples from 50 patients with tonsil or tongue base carcinoma were tested using the RNAscope HPV-test, p16 immunohistochemistry, and chromogenic in situ hybridization for high-risk HPV-DNA. The results were compared with those of qRT-PCR on matched fresh-frozen samples. Compared with the reference test, the sensitivity, specificity, positive, and negative predictive values of the RNAscope HPV-test and of p16 immunohistochemistry were 93%, 94%, 96%, 88% and 96%, 93%, 96%, and 93%, respectively. Five cases were discrepant between the RNAscope HPV-test and p16-immunohistochemisrty. The RNAscope HPV-test demonstrated excellent analytical performance against the 'gold standard' and is easier to interpret than chromogenic in situ hybridization. p16-immunohistochemistry also performed very well, however its main weakness is that it is an indirect marker of the presence of HPV. These data suggest that the RNAscope HPV-test is a promising test that could be developed as a clinical standard for the precise identification of HPV-driven oropharyngeal squamous cell carcinoma.

Presence of high risk HPV DNA but indolent transcription of E6/E7 oncogenes in invasive ductal carcinoma of breast

Pathology - Research and Practice

2016 Sep 22

Wanga D, Fu L, Shah W, Zhang J, Yan Y, Ge X, He J, Wang Y, Xu Li.
PMID: - | DOI: dx.doi.org/10.1016/j.prp.2016.09.009

Background and aims

The causative role of high risk human papillomavirus (HR-HPV) in breast cancer development is controversial, though a number of reports have identified HR-HPV DNA in breast cancer specimens. Nevertheless, most studies to date have focused primarily on viral DNA rather than the viral transcription. The aim of this study was to investigate the presence of HR-HPV in breast cancer tissues at HPV DNA level and HPV oncogenes mRNA level by in situ hybridization (ISH).

Methods

One hundred and forty six (146) cases of breast invasive ductal carcinoma(IDC) and 83 cases of benign breast lesions were included in the study. Type specific oligonucleotide probes were used for the DNA detection of HPV 16,18 and 58 by ISH. HR-HPV oncogenes mRNA was assayed by novel RNAscope HR-HPV HR7 assay ISH. p16 protein expression was evaluated by immunohistochemistry (IHC).

Results

HR-HPV 16,18 and 58 DNA were detected in 52 out of 146 (35.6%) IDC and in 3 out of 83 (3.6%) benign breast lesions by ISH. The HR-HPV mRNAs was detected only in a few specimens with strong HPV DNA positivity(4/25) in a few scattered cancer cells with very weak punctate nuclear and/or cytoplasmic staining. p16 over-expression did not correlate with the HPV DNA positive breast cancer samples(17/52 HPVDNA+ vs 28/94 HPV DNA-, p = 0.731).

Conclusions

HR-HPVs certainly exist in breast cancer tissue with less active transcription, which implies that the causal role of HPV in breast cancer development need further study.

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	Description
sense Example: Hs-LAG3-sense	Standard probes for RNA detection are in antisense. Sense probe is reverse complent to the corresponding antisense probe.
Intron# Example: Mm-Htt-intron2	Probe targets the indicated intron in the target gene, commonly used for pre-mRNA detection
Pool/Pan Example: Hs-CD3-pool (Hs-CD3D, Hs-CD3E, Hs-CD3G)	A mixture of multiple probe sets targeting multiple genes or transcripts
No-XSp Example: Hs-PDGFB-No-XMm	Does not cross detect with the species (Sp)
XSp Example: Rn-Pde9a-XMm	designed to cross detect with the species (Sp)
O# Example: Mm-Islr-O1	Alternative design targeting different regions of the same transcript or isoforms
CDS Example: Hs-SLC31A-CDS	Probe targets the protein-coding sequence only
EnEm	Probe targets exons n and m
En-Em	Probe targets region from exon n to exon m
Retired Nomenclature
tvn Example: Hs-LEPR-tv1	Designed to target transcript variant n
ORF Example: Hs-ACVRL1-ORF	Probe targets open reading frame
UTR Example: Hs-HTT-UTR-C3	Probe targets the untranslated region (non-protein-coding region) only
5UTR Example: Hs-GNRHR-5UTR	Probe targets the 5' untranslated region only
3UTR Example: Rn-Npy1r-3UTR	Probe targets the 3' untranslated region only
Pan Example: Pool	A mixture of multiple probe sets targeting multiple genes or transcripts

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Probes for P16

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Abstract

IMPORTANCE:

OBJECTIVE:

DESIGN, SETTING, AND PARTICIPANTS:

MAIN OUTCOMES AND MEASURES:

RESULTS:

CONCLUSIONS AND RELEVANCE:

Abstract

Background

Methods

Results

Conclusions

Abstract

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