DMK Chief M Karunanidhi today turned 88, but kept his birthday celebrations on a low-key. Karunanidhi told reporters that party cadres who have dedicated themselves to social and political renaissance should keep going without forgetting that bad friendship will end in trouble. The birthday celebrations, usually a platform for DMK to display its strength, was low-key ostensibly after the party-led Front was routed in the polls and with Karunanidhi's daughter Kanimozhi and DMK's trusted member and former Telecom Minister A Raja lodged in Delhi's Tihar jail for their alleged role in the 2G scam.Besides, Karunanidhi's grand nephew and Union Textiles Minister Dayanidhi Maran is also in the eye of a storm over alleged pay-offs by a Malaysian company which benefited from equity sold by Aircel. Maran has denied the charges.Karunanidhi had issued a statement on Thursday night, saying he was not in the frame of mind to participate in any event other than the planned wreath laying ceremony at memorials of Anna (former Chief Minister Annadurai) and Periyar (rationalist leader E V Ramasamy) on his 88th birthday.