•lung cancer ( SCLC, NSCLC) is the most frequent cause of cancer death -American women and man •Romania –10.000 new cases /year •rates increasing in… [618038]

microRNAs as Next Generation
Biomarkers for Lung Cancer
Iurca Ioana

General overview
•lung cancer ( SCLC, NSCLC) is the most frequent cause of
cancer death -American women and man
•Romania –10.000 new cases /year
•rates increasing in the past 10 years
•non specific symptoms, until far advanced
•75% of lung cancers are recognised => locally advanced or
metastatic stages => less than 15% five -year overall survival
rate
•insuffiency of specialized and precise means for immediate
diagnosis

“You can change a phenotype by modulating a single
miRNA ” Thomas Wurdinger , HMS
•class of small noncoding RNA molecules
•19-25 nucleotides fragments controlling genes expression
by binding to mRNA
•degrades or inhibits proteic synthesis of mRNA
•role in disease still in research ( cancer)
•> 2500 types
•revealed in serum, sputum
•function as promoters or inhibitors of tumor gene according
to substrate -protoncogenes TSG
•controlled by other epimechanisms
•posttranscriptional event
•www.mirbase.org

•A meta -analysis of 20 published miRNA studies in lung
cancer -> total = 598 tumor , 528 non -cancerous control
samples, they identified a statistically significant miRNA
signature of seven upregulated (miR -21, miR -210, miR -182,
miR-31, miR -200b, miR -205 and miR -183) and 8
downregulated (miR -126-3p, miR -30a, miR -30d, miR -486-
5p, miR -451a, miR -126-5p, miR -143 miR -145)
•this meta -analysis reaching is suited and adequate solution
for identification of expressing miRNA meta -signature by
conecting certain distinct miRNA expression research
•This study is particular to comparison of tumor and
noncancerous tissues only.
•It would be interesting to evaluate miRNAs correlated with
progression free survival, staging, prognostic, clinical
response to treatment.

Potential miRNA for Lung cancer
•serum -miR-21-3p, -205-5p, -205-3p, -141, 200c
-miR -24, -205, -30d
•plasma -miR-21, -155, miR 145
•exosome -miR-17-3p, -21, -106a, -146, -155, -191,-192, -203, -205, –
210, -212, -214
•sputum -miR-205, -210, -708
Plasma miRNAs
–define risk for lung cancer in asymptomatic initial stages
–diagnose lung cancer in screen identified nodules -80%
efficiency
–define expectation of life in screen -detected lung cancer

MicroRna expression in cancer
•12 years ago was reported the first association between miRNAs and
cancer by Calin et al
•fundamental biomarkers that may control >30% of human genes and could
be a part of the massive cancer puzzle
•adjustement of miRNA expression have been seen in hcc, lung, breast,
stomach, pancreatic cancer progression and chemoresistance
• expression will decline the establishment and translatability of the
target tumor suppressor mRNA
Principle -> decreased expression of the tumor suppressor
Development tumor formation
• expression of the miR will regulate transcript stability of the target
oncogene mRNA
Leads to increased expression of the oncogene
Increased tumor evolution

Tumor supressor microRNA
let-7 miRNA
•first in human
•suppress expression RAS, MYC, HMGA 2, CDK6
•generally reduced in human lung cancers
•reduced let-7miRNA expression was very much
associated with shortened postoperative surveillance
•Overexpression of let-7miRNA in A549 lung
adenocarcinoma cell line repressed lung cancer cell
growth in vitro

miR-34Family
•miR-34a,miR-34b, and miR-34cis precisely caused by TP53
in reply to DNA deterioration, regulating cell cycle delay
and programmed cell death in tumour
•is down -regulated in lung tumour , directing to the up –
regulation of miR-34reference genes, such
asMET ,BCL2 ,PDGFR -α(PDGFRA ), and PDGFR -β(PDGFRB )
•the up -regulation of MET and BCL2 by decreased miR-
34expression induces cell proliferation
•MiR-34dependent PDGFR -α/β downregulation supresses
the process of promoting the development of the tumour
and strengthens TRAIL (TNF -related apoptosis -inducing
ligand )-induced cell death in lung neoplasm

miR-200 family
-miR-200a, miR -200b, miR-200c, miR-429
-role in the promotion of EMT
-regulation of ZEB
-transcription factors (ZEB1 and ZEB2),
-E-cadherin
-vimentin
-the down -regulation promotes EMT in the
progression of lung cancer

Smoking and microRNA expression
•Nodal et al (2014 ) discovered that miR-210 is associated with
cigarette smoking and pack -years consumed
•On the other hand, miR-342,miR-151,miR-501-3p,miR-29b,miR-
30d,miR-497,miR-222,miR-505,miR-34b,miR-500 miR-99a-3pare
contrary connected with pack -years consumed
•MiR-210-was remarcably expressed in heavy -smoking patients’
lung adenocarcinoma , has been combined with hypoxia in lung
tumour and positively regulates HIF -1a
•particular microRNAs negatively correlated with pack -years persist
as tumor suppressor microRNAs , and their expression may be
regulated by epigenetic system
•Lu et al discovered that lncRNA CCAT1, c-Myc could be interested in
cigarette smoke extract -induced lung tumorigenesis along let-7c
•Feedback connection along let-7cbetween CCAT1 and c -Myc might
be involved in smoking -associated lung cancers

Oncogenic microRNAs
miR-21
•upregulated miRNAs -> solid tumours ; overexpressed -leukemia
•Jiang et al revealed that endogenous miRNAs are strongly present in the
patients sputum
•initiates cancerogenesis over suppressing of multiple bad regulators of
RAS, MEK and ERK pathway and suppression of apoptosis
•miR-21 was found to be substantial in sputum of NSCLC patients as
compared with tumour -free subjects
•the same study it was shown that miR -21 overexpression in sputum was a
more responsive biomarker (70%) than current sputum cytology (48%) in
determining lung cancer
•Markou and co found that overexpression of mature miR-21was an
autonomous negative prognostic factor for global survival in NSCLC
patients
•overexpressed miR-155in lung cancer cells correlated with reduced patients
expectation of life
•relevant role in evolution of heart condition

miR-17-92Cluster
•miR-17-92polycistronic group contains 7 distinctive
microRNAs (miR-17-3p,miR-17-5p,miR-18a,miR-
19a,miR-20a,miR-19b-1, and miR-92a) and locates
in intron 3 of the C13orf25 gene at 13q31.3
•expected to be overexpressed in lung
neoplasm(especially in SCLC)
•Overexpression ofmiR-17-92cluster down –
regulates E2F1 ,HIF1A, PTEN developing cell
reproduction and tumour growth

miR-155
•B-cell malignancies
•transcribed from a noncoding RNA BIC
•physiologically, miR -155 is a necessary partcipant in
hematopoiesis , the immune response and inflammation .
•upregulated in several types of malignancies
•has an important role in pathogenesis of B cell diseases.
•the oncogenic objective of miR -155 can be interpreted by its
spotted genes and the involved underlying molecular
pathways
•overexpression of miR -155 in mice results in expansion of
lymphoproliferative disorders at the same time subsequent
withdrawal , induces remission

Research for prognostic
•tested as potential prognostic biomarkers
•In 2004, Takamizawa et al. revealed that let-7expression is diminished in
lung tumour than in normal lung cell and it was correlated with small
chance of survival.
•Further more, overexpression oflet-7in lung adenocarcinoma cellule
profile repressed cell expansion.
•Observations of let-7expressions in adenocarcinoma in situ and in invasive
adenocarcinoma were correlated with the association of let-7expression
with the growth of pulmonary adenocarcinoma
•the expression in AIS of let-7was decreased related to matched normal
lung cell, implying that let-7expression was diminished in the initial stage
of lung tumourigenesis .

•Unusual, the expression of let-7was reduced in mucinous AIS compared
non-mucinous AIS.
•The different interpretation between those 2 types of AIS propose a
combination between microRNA expression and histology (alike in
identical type of AIS).
•Therefore involvement of microRNA expressions are connected to
morphology, cancer evolution or driver alterations.
•2006 Yanaihara et al described first microRNA in lung neoplasm
•Method: 104 NSCLCs (65 adenocarcinomas and 39 SCLC) compared to
normal lung tissues
•using microarray -analyses of microRNA .
•They determined the significant level of miR-155and the lessened
expression of let-7a-2as biomarkers of low prognosis for NSCLC subjects
•validity was confirmed by using a separated RT-PCRResearch for prognostic

•2008 Yu et al. revealed a five -microRNA signature ( let-
7a,miR-221, miR -137,miR-372, and miR-182) that divided
a total of 56 NSCLC cases into good -prognosis and poor –
prognosis group.
•they confirmed that the 5 -microRNA signature divided 62
NSCLC testing cases into 2 divisions with good and poor
prognosis
•moreover, they confirmed the 5 -microRNAs signature as a
prognostic indicator experimenting an independent cohort
set of 62 NSCLCs
•in conclusion, 5 -microRNA signature was used as a
prognostic classifier for NSCLC with the same stage or SCLC
and adenocarcinomas

MicroRNAs and Therapeutically -Targeted Molecules
•Separately from directly driver alterations, other molecular targets
are favourable and hopeful for fighting cancer
•PDL1 The immune checkpoints mechanism is very important in
reressing the anti -tumor T -cell-mediated immune reaction in the
tumor growth
•PD-L1 ( CD274, B7 -H1) is an immune modifier that improves
immunosuppression by binding to PD -1 of T -lymphocytes.
•Therapeutic antibodies targeting PD -1 and PD -L1 are effective in
many neoplasm categories, especially in lung cancer ( NSCLC and
SCLC )
•PD-L1 expression in cancer cells has been implied as a anticipating
marker of the clinical benefit rate to PD -1/PD -L1-targeted therapy

MicroRNAs and Therapeutically -Targeted Molecules
•If PD -L1 is positive in lung adenocarcinoma it is associated
with increasing death rate and EGFR wild -type status
•PD-L1 has been noted to be regulated by TP53 via miR-34.
The 3′ -UTR of the PD-L1mRNA carries a miR-34binding site.
•In cases of NSCLC, TP53 transcriptionally promoted miR-
34expression, and increased miR-34targeted PD-L1mRNA,
leading to the loss of PD -L1 protein
•they established that the curative role of delivery of miR-
34a combined with standard treatment and radiotherapy,
demonstrated a better clinical benefit rate
•this combined therapy may describe an advanced model of
immunotherapy

Conclusions
•role of several miRNAs are currently under investigation in
diagnostic, prognostic, predictive value for numerous
categories of cancer
•there is a precise interest in microRNAs correlated with
histological category, genetic mutations, therapeutically –
targeted molecules and environmental carcinogens in lung
cancer. The circulating microRNA signature for the early
diagnostic of lung tumour and the significance of them as the
modulators of tumor immune response are also very
important

Conclusions
•there is an increased capacity in microRNA evaluation for
cancer research because microRNAs are far less
degradeted in FFPE fragments than mRNAs and are
present also in body fluids
•further research is warranted to use microRNAs as
diagnostic markers and conduct microRNA -based
treatments in clinical practice;
•requires considerable contribution in effort and capital
•miRNAs expression could represent an useful appliance
to define observation of oncogene addicted NSCLC